tech-2022_05(98)

№ 5 (98) май, 2022 г. 35 Gp, million tons II 6 31,8 I 5 30 II-design case 26,8 4 3 25 2 1 21,8 I-design case 20 21,2 17,6 13,9 15 10 5 tIIн1= 4,5 tIIн2= 9,9 tIIн3= 4,6 I - scheme tIн4= 4,6 II - scheme tIн1= 4,5 tIн2= 4,3 tIн3= 5,6 t, years 0 Figure 1. Graph of transportation mastering in each calculation case Finding the best way to increase the capacity of the Before proceeding to consider the issue of making a railways of Uzbekistan in order to switch transit cargo decision when justifying the strengthening of the capac- flows between China, Central and South Asia is a diffi- ity of the Angren-Pap railway projects under conditions cult task, which is due, on the one hand, to the uncer- of uncertainty and risks, we will formulate the concepts tainty of the time for switching transit cargo flows, and of \"uncertainty\" and \"risk\" themselves, and establish the on the other hand, the reliability of the initial infor- differences between them. mation on the size of transit cargo flows between China, Central and South Asia. Uncertainty implies the presence in the information block of factors for which it is impossible to give deter- As can be seen from the graph, when choosing the ministic (single-valued) values, i.e. information is in- variant of the scheme for mastering the transportation of complete or inaccurate. In our case, such factors include, the Angren-Pap railway line, a rather long period for example, information about the volume of traffic or (15 years) of operation of the line is considered, while, the size of traffic in the future, which depend on the for- obviously, deviations in traffic volumes are possible, mation of a corridor between China and Central and both in time intervals and in general over the horizon South Asia. calculation (this depends on many factors independent of each other). Uncertainty factors can be divided according to their genetics into external and internal. External factors The prospect of developing the existing Angren-Pap include information, for example, on the size and struc- line as a link between China, Central and South Asia ture of transportation, which depend on the country's may not provide large transit cargo flows between macroeconomic development programs, the legal China, Central and South Asia, since there are bottle- framework, the actions of competitors in the transport necks on this railway line that significantly reduce services market, etc. throughput and carrying capacity, which need to be sub- jected to an increase in the capacity of the line when Internal - this is, first of all, the competence of the switching transit cargo flows between China, Central apparatus of managers of the railway company when and South Asia. The same can be said about the schemes choosing a strategy for its functioning, and here, in our of options for strengthening the operated railway line opinion, it is important to involve science and educa- Angren - Pap, i.e. there are conditions of uncertainty. tional institutions in solving this problem. Obviously, the longer the calculation horizon, the higher the level of uncertainty and risk when adopting a partic- There are various methods for determining the vol- ular scheme based on the results of an economic assess- ume of traffic and the size of traffic for the estimated ment of the effectiveness of investments [1]. time and perspective, showing that uncertainty cannot be interpreted as a complete lack of information, but only about its incompleteness and inaccuracy. Hence the 42

№ 5 (98) май, 2022 г. conclusion: - the available information must be used as risk that differ in place and time of occurrence, a combi- \"conditionally accurate\" when assessing the options for nation of external and internal factors affecting their the program to increase the capacity of the operated rail- level and, consequently, according to the method of their way Angren - Pap. If new information is received in the analysis and methods of description. process of project implementation, then, obviously, it is necessary to correct the course (process, technology, Risk classification consists in systematizing a large scheme) of implementation. number of risks according to certain characteristics and criteria, which will make it possible to combine a subset The risk should be understood as the probability of of risks into more general concepts. The classification of occurrence of such conditions that lead to negative con- risks, which is recommended for evaluating investment sequences in the course of implementing decisions to in- projects, is shown in fig. 2. In addition, a brief descrip- crease the capacity of the operated Angren-Pap railways tion of each type of risk is given, taking into account or its individual elements. the particular justification for increasing the capacity of Uzbekistan's railways in order to switch transit In the process of strengthening the capacity of the cargo between China and Central and South Asia. operated railways in order to switch transit cargo be- tween China and Central and South Asia, the Uzbek rail- ways are faced with a combination of various types of Figure 2. Classification of project risks The systematic risks include, first of all, the risks of of an international corridor between China and Central force majeure (Fig. 3), where the first place is the risk of and South Asia is envisaged in a complex mountainous impact on the progress of the project and its (object) area, which is a seismic hazard zone. In winter, there functioning during the life cycle of natural disasters will be periodic threats of avalanches, mudflows and (earthquakes, avalanches, mudflows). , landslides, etc.) landslides in the area of the international corridor be- [4-5]. tween China and Central and South Asia. It should be noted that the territory of Central Asia is located in a seismically dangerous zone. The project Figure 3. Systematic risks If we talk about country risk (Figure 3), then here we arise due to adverse changes in the political situation are talking, first of all, about the political and economic in the state or the actions of local authorities. Vivid stability of the country, the size of its participation in examples of the manifestation of country risk are foreign economic relations. Country risk can be divided the events that occurred in some countries in 2010-11. into political (Figure 4) and economic (Figure 5). Political (eg Libya, Syria, Sudan, etc.) and current events (Syria, risks of direct losses and losses or shortfalls in profits Yemen, Ukraine, etc.). 43

№ 5 (98) май, 2022 г. Figure 4. Possible political risks The successful development of the project to effectiveness of decisions made. As previously noted, strengthen the capacity of Uzbekistan's railways in order the construction of a new railway line through Afghani- to switch transit cargo between China and Central and stan has continued, which will provide Central Asia with South Asia largely depends on a stable political and eco- access to the seaports of Iran and Pakistan on the coast nomic situation in the region. The instability of the situ- of the Indian Ocean. However, today it comes up against ation in Central Asia will have a negative impact on the the unresolved situation in Afghanistan. Figure 5. Possible economic risks Economic risks are caused by unfavorable changes • the need for additional investments in the infrastruc- in the economies of countries. When choosing design ture and rolling stock of railways due to their quality ser- parameters for increasing the capacity of the operated vice; railways of Uzbekistan in order to switch transit cargo between China and Central and South Asia, the follow- • lack of capacity and low technical level of develop- ing types of uncertainty and economic risks seem to be ment of the locomotive and car fleet; the most significant: • lack of infrastructure development (warehouses, • lack of the state budget and own funds of the Uzbek terminals, etc.); railways to increase the capacity of the railways; • reduction of transit cargo flows due to the develop- • a decrease in the volume of cargo traffic due to ment of alternative railway routes bypassing the territory of the fall of the state economy and the economic crisis in the Uzbekistan; region; • high level of inflation; • lack of conversion for foreign investors. 44

№ 5 (98) май, 2022 г. At the same time, there are “bottlenecks” on the rail- Uzbekistan's railways will become a serious obstacle to way network of the Republic of Uzbekistan that signifi- the implementation of plans to increase the capacity of cantly reduce the throughput and carrying capacity and Uzbekistan's railways in order to switch transit cargo be- require significant modernization. The most important tween China and Central and South Asia. The intergov- work in this direction is to reduce the depreciation of ernmental agreement on the permanent operation of Uz- fixed assets, and for rolling stock (diesel locomotives - bekistan's railways should become a supporting legal 76%; freight electric locomotives - 30.8%; freight cars - document, creating the basis for the implementation of 70%; passenger cars - 49.1%) and track facilities (rail- draft plans to strengthen the capacity of Uzbekistan's way tracks – 33%), this figure is much higher. railways in order to switch transit cargo between China and Central and South Asia, as well as the second stage It is important to note that the absence of an inter- of development of the country's railway network. governmental agreement on the permanent operation of References: 1. Умаров Х.К., Свинцов Е.С. Математическая модель по прогнозированию грузопотока Китая и Южной Кореи между Центральной и Южной Азией // Вестник. Ростовского государственного университета путей сообщения. – 2017 – Вып. 2 (66). – С. 69-75. 2. Umarov Kh. Mathematical model for forecasting freight flows between Ferghana valley and other regions of Uzbekistan. Philosophical Readings XIII.4 (2021), pp. 1318-1328; 3. Umarov Xasan, Botirov Otanur. THE ROLE OF CONSTRUCTION OF THE ANGREN-PAP RAILWAY LINE IN THE PLANS OF INTERNATIONAL TRANSPORT AND ECONOMIC RELATIONS // Universum: технические науки. 2021. №6-5 (87). 4. Lesov K.S., Kenjaliyev M.K., Mavlanov A.Kh. and Tadjibaev Sh.A. Stability of the embankment of fine sand rein- forced with geosynthetic materials. //E3S Web of Conferences; CONMECHYDRO – 2021, Les Ulis, - Vol. 264. DOI:10.1051/e3sconf/202126402011. 5. Lesov K.S., Tadjibaev Sh.A. and Kenjaliyev M.K., Technology for strengthening slopes of the subgrade of railroads made of sandy soils using geosynthetic materials. //Problems of architecture and construction. 4 pp. 15-18, (2019). 45

№ 5 (98) май, 2022 г. FOOD TECHNOLOGY INFLUENCE OF SPRINKLING ON THE GROWTH AND DEVELOPMENT OF PROMISING VARIETIES OF WINTER WHEAT Isashov Anvarjon Doctor of Agricultural Sciences, Professor of Andijan Institute of Agriculture and Agrotechnology, Uzbekistan, Andijan E-mail: [email protected] Xusanov Dilmurod Dexkanovich Assistant of Andijan Institute of Agriculture and Agrotechnology Uzbekistan, Andijan ВЛИЯНИЕ ДОЖДЕВАНИЯ НА РОСТ И РАЗВИТИЕ ПЕРСПЕКТИВНЫХ СОРТОВ ОЗИМОЙ ПШЕНИЦЫ Исашов Анварджон д-р с.-х. наук, профессор Андижанского института сельского хозяйства и агротехнологии, Республика Узбекистан, г. Андижан Хусанов Дилмурод Дехканович ассистент Андижанского института сельского хозяйства и агротехнологии, Республика Узбекистан, г. Андижан ABSTRACT This article describes how the irrigation method affects the growth and development of promising varieties of winter wheat \"Grom\" and \"Nodira\" on light gray soils of the Andijan region. АННОТАЦИЯ В данной статье описано, как способ орошения влияет на рост и развитие перспективных сортов озимой пшеницы «Гром» и «Нодира» на светло-серых почвах Андижанской области. Keywords: groundwater, chdns, slope length, moisture thickness, irrigation methods. Ключевые слова: подземные воды, предельная полевая влагоёмкость (ППВ), длина склона, мощность увлажнения, способы орошения. ________________________________________________________________________________________________ Today, winter wheat is grown on 220.4 million based on the water consumption of each crop, depending hectares in more than 132 countries. Of this, 12.3% is on the natural and climatic conditions. irrigated land, the average grain yield is 31.1 quintals per hectare, and the bulk of food is grown on these lands1. Adherence to scientifically based irrigation In recent years, the sharp change in climate has caused a procedures in the context of water shortages in world number of inconveniences in the cultivation of grain agriculture today has a positive impact on increasing crops. A number of countries around the world, crop yields and its quality. In this regard, it is important including the United States, Australia, Russia, China, to conduct research to improve modern science-based India, Pakistan, Bangladesh, North Africa, Central Asia, irrigation procedures that save water and resources, as South Kazakhstan, Transcaucasia, are finding solutions well as to improve the reclamation of lands. through the introduction of modern agricultural technologies and reclamation measures. Therefore, the The study was conducted in the Andijan region in light norm of seasonal irrigation, the timing of irrigation is gray, medium-heavy sands with mechanical composition, groundwater level at a depth of 1.5-2.0 meters. The experimental system is presented (Table 1). __________________________ Библиографическое описание: Isashov A., Xusanov D. INFLUENCE OF SPRINKLING ON THE GROWTH AND DEVELOPMENT OF PROMISING VARIETIES OF WINTER WHEAT // Universum: технические науки : электрон. научн. журн. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13685

№ 5 (98) май, 2022 г. The experiments were performed in 4 repetitions. the edges is v-0.9 m, the area of the option is 4.8x 50 = The area of the fold 4 times is 0.6 x 8 = 4.8 m2, 240 m2, the area of the fold is 240 x 5 = 1200 m2 , total the length of the edge is L-50 m, the distance between area 1200 x4 = 4800 m2 or 0.46 ha. Table 1. Experimental system Irrigation method and soil moisture Calculated moisture thickness, cm before irrigation(wilting point) % Options during planting During the ripening time and harvesting flowering period Varieties of autumn wheat 1 Irrigation (control)70-70-60 0-50 0-70 0-100 2 Irrigation with a flexible hose 70-70-60 0-50 0-70 0-100 3 Irrigation with a flexible hose 65-65-60 0-50 0-70 0-100 4 Sprinkler Irrigation 0-50 0-70 0-100 70-70-60 0-50 0-70 0-100 5 Sprinkler Irrigation 65-65-60 Data on growth and development of winter wheat growth of winter wheat. However, the height of stalks depending on irrigation regimes are given in Table 2. and the number of stalks of winter wheat do not determine the yield, but only increase its dry mass. It According to the data, in 2022, the optimal was observed that the soil moisture content was higher irrigation regime for winter wheat in the \"Grom\" variety than the 5 variant values set at 65-65-60% compared to is 70-70-60% of the wilting point in the irrigated control wilting point before irrigation. variant. and 856 cm, the number of stems was 884 in the collection and 3.9 in the tubing. Similar data were obtained for winter wheat variety \"Nodir\". In 5 variants of rain-fed irrigation with soil moisture 65-65-60% relative to wilting point, these values are: In conclusion, for optimal growth and high yield of 8.8; 17.9 and 84.6 cm; the number of stems was 860, and winter wheat, it should be 65-65-60% of the wilting 4.8 and 4.6 per plant, respectively, which is 2.2, -3.5; point relative to the limited field capacity in terms of and 856 and 1.3 compared to variant 1. ; 1.0 is the pre-irrigation soil moisture phases, and it is advisable to excess. It should be noted that the high soil moisture irrigate by rain. content of 70-70-60% had an optimal effect on the Growth and development of winter wheat Table 2. Soil moisture, Stem height, cm Number of stems, pcs yields in% of ChDNS tufts In the tube Numbers tufts In the tube maturing tufts In the tube milky-wax 3,5 3,9 3,8 4,1 variety \"Grom\" 3,8 4,1 4,5 4,6 1 70-70-60 7,6 14,4 83,0 856 884 4,8 4,6 2 70-70-60 3 65-65-60 7,5 15.6 84,2 850 886 3,4 3,8 4 70-70-60 3,8 4,0 5 65-65-60 7,8 15.9 84,4 856 883 3,8 4,1 3,8 3,0 1 70-70-60 8,4 16,3 84.2 812 836 4,0 3,2 2 70-70-60 3 65-65-60 8,8 17,9 84,6 860 880 4 70-70-60 5 65-65-60 variety \"Nodir\" 7,4 14,1 82,0 859 880 7,6 15.8 84,0 854 883 7,8 15.9 84,4 856 883 8,6 16,7 84.6 810 832 8,9 17,9 84,8 862 884 47

№ 5 (98) май, 2022 г. References: 1. Исашов А., Мирфозилов Н., Аминов Ш. ВЛИЯНИЕ РАЗНЫХ МЕТОДОВ ОРОШЕНИЯ НА РАЗВИТИЕ И УРОЖАЙНОСТЬ РАННЕГО И ПОЗДНЕГО КАРТОФЕЛЯ В УСЛОВИЯ АНДИЖАНСКОЙ ОБЛАСТИ // Life Sciences and Agriculture. – 2020. – №. 3-1. – С. 14-21. 2. Исашов А. и др. ВОЗДЕЛЫВАНИЕ КАРТОФЕЛЯ ПРИ РАЗНЫХ СПОСОБАХ ПОЛИВА //Universum: технические науки. – 2021. – №. 12-2 (93). – С. 37-41. 3. Исашов А., Норкузиев А., Кодыров Р. ВЛИЯНИЕ НОРМЫ КОРМЛЕНИЯ И ОРОШЕНИЯ ОЗИМОЙ ПШЕНИЦЫ НА УРОЖАЙНОСТЬ ЗЕРНА И СОЛОМЫ // УПРАВЛЕНИЕ ИННОВАЦИОННЫМ РАЗВИТИЕМ АГРОПРОДОВОЛЬСТВЕННЫХ СИСТЕМ НА НАЦИОНАЛЬНОМ И РЕГИОНАЛЬНОМ УРОВНЯХ. – 2020. – С. 108-112. 4. ИСАШОВ А., КАДИРОВ Р., ТАДЖИБАЕВ А. Задачи реконструкции и практика расчета режима орошения озимой пшеницы в Узбекистане //Российский электронный научный журнал. – 2013. – №. 3. – С. 3-6. 5. Исашов А., Мирфозилов Н., Аминов Ш. THE EFFECT OF DIFFERENT WATERING METHODES IN GROWING AND FERTILITY OF EARLY AND LATE TYPES OF POTATOES IN ANDIJAN REGION’S CONDITION // Life Sciences and Agriculture. – 2020. – №. 3. – С. 14-21. 48

№ 5 (98) май, 2022 г. DRYING PRODUCTS WITH INFRARED RAYS Bakhodir Kholdorov Associate Professor Jizzakh Polytechnic Institute (JizPi), Uzbekistan, Jizzakh E-mail: [email protected] Otabek Irmatov Assistant Jizzakh Polytechnic Institute (JizPi) Uzbekistan, Jizzakh Shokir Issaqov Assistant Jizzakh Polytechnic Institute (JizPi) Uzbekistan, Jizzakh Jasur Sadullaev Master Jizzakh Polytechnic Institute (JizPi) Uzbekistan, Jizzakh СУШКА ПРОДУКТОВ ИНФРАКРАСНЫМИ ЛУЧАМИ Холдоров Баходир Баратович доцент Джизакский политехнический институт Республика Узбекистан, г. Джизак Эрматов Отабек Саидович ассистент Джизакский политехнический институт Республика Узбекистан, г. Джизак Иссаков Шокир Аллаберди ўғли ассистент Джизакский политехнический институт Республика Узбекистан, г. Джизак Садуллаев Жасур Мансур ўғли магистр Джизакский политехнический институт Республика Узбекистан, г. Джизак ABSTRACT By maximizing the nutritional value and taste of products, the use of infrared rays during drying increases the heat density on the product surface, and the intensity of the process can be increased to a certain extent due to the fact that shortwave IR rays penetrate deeper into the material. АННОТАЦИЯ Максимально повышая пищевую ценность и вкусовые качества продуктов, использование ИК-лучей при сушке увеличивает плотность тепла на поверхности продукта, а интенсивность процесса можно в определенной степени увеличить за счет того, что коротковолновые ИК-лучи проникают глубже в материал. Keywords: IR-rays, range, intensity, vibration, electromagnetic, thermoradiation, combination, absorption. Ключевые слова: ИК-лучи, диапазон, интенсивность, вибрация, электромагнитное, термоизлучение, сочетание, поглощение. ________________________________________________________________________________________________ __________________________ Библиографическое описание: DRYING PRODUCTS WITH INFRARED RAYS // Universum: технические науки : электрон. научн. журн. Kholdorov B.B. [и др.]. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13701

№ 5 (98) май, 2022 г. Research in recent years has focused on improving energy transfer, no significant moisture loss from the drying methods that maximize the nutritional value and product is observed. In this case, the moisture is redis- taste of products, as well as ensuring high process effi- tributed along the thickness of the layer. In the case of ciency. thermal moisture permeability, the transition of the bulk of the moisture to the vapor phase and the transfer of a Infrared drying, its types and possibilities of appli- small amount of moisture into the layer leads to dehy- cation by combining heat carriers. By using infrared rays dration of the surface layer. These studies have shown in the drying of products, the heat density reaching the that the duration of IR-drying is 1.5-2 times shorter than surface of the product increases and the intensity of the other methods. process can be increased to a certain extent due to the fact that short-wave IR rays penetrate deeper into the In order to intensify the drying process and maintain material. the high quality of the finished product, it is necessary to determine the physicochemical, structural-mechanical, Infrared rays include rays with wavelengths ranging thermoradiation and heat-physical properties of the prod- from 0.77 to 340 μm. In practice, rays with a wavelength uct, as well as the basic laws of heat treatment. of 0.77 to 5-6 microns are used for drying. IR-irradiation of thick material results in a certain temperature change Processing in the electromagnetic field in the IR range (compared to normal convective drying). Also, the flow corresponds to a wavelength of 0.76-750 μm, which is of moisture into the material brings with it a certain conventionally divided into three smaller ranges: long- amount of heat, which accelerates the internal heat ex- wave - 750-25 μm, medium-wave - 25-2.5, short-wave - change. To increase the intensity of thermoradiation 2.5-0.76 μm. The range of IR radiation is represented by drying, IR rays are required to penetrate the material as three directions: wavelength - short infrared range (NIR) deeply as possible. It depends on the conductivity of the to 0.75-1.4 μm; average - up to 1.4-3 microns (MIR) and material and the wavelength of the IR rays. The lower it long infrared range - up to 3-1000 microns (FIR). is, the greater the penetration capacity of infrared rays. As the layer thickness decreases and the moisture con- Water and organic components, especially protein tent in the material decreases, the permeability of the and starch, absorb energy over a long range (wavelength products increases. 2.5mkm), while many foods have low absorption prop- erties of wavelengths smaller than 2.5mkm. In IR heat- Processing of agricultural products in the electromag- ing, short waves are absorbed by water, while long netic field in the IR-RAN range is a combination of heat waves are absorbed by the surface of the product. This transfer, in which infrared rays are converted into ther- means that it is more efficient to dry products of mini- mal energy without direct interaction between the en- mum thickness on long-range waves (25-100mkm), ergy source and the product, with energy transfer as while it is more efficient to dry thick pieces on short- electromagnetic oscillations entering the product. Infra- range waves (0.75-3.0). red rays have the ability to penetrate the product to a cer- tain depth and affect the molecular structure of the ma- In studying the mechanism of action of IR rays on terial, which ensures a rapid rise in temperature inside food, they are described as a matrix of various biological the product. Infrared drying is based on the absorption polymers, salts, water. Each element in the food system of infrared rays of a certain wavelength by the moisture absorbs IR rays of a certain wavelength. Proteins range in the product. from 6 to 9 microns cha absorbs waves in the range of cha, lipids absorb almost all waves in the range of 0.25 The boiling point of water depends on the total pres- to 10 μm, but absorption peaks occur in the range of 3-4 sure, the lower the pressure, the lower the boiling point. μm, 6 μm and 6-9 μm, shaker absorbs waves in the range Loss of moisture at low temperatures allows complete of 7-10 μm and 0.5-4 μm . The maximum absorption of preservation of almost all proteins and amino acids, water is 2 μm and the minimum absorption is 6 μm at carbohydrates, biologically active substances, vitamins, wavelength. minerals, dyes and odors. Vacuum drying is the most optimal method. The use of IR-heating in the drying of thin layers is very effective, as the drying intensity increases by 1.5-2 Despite the intensive (rapid) heating of the surface times, energy consumption is reduced by 1.5 times. layer during the initial period of the infrared method of List of references: 1. Douglas J. Arent, Alison Wise, Rachel Gelman. The status and prospects of renewable energy for combating global warming // Energy Economics, Volume 33, Issue 4, July 2011, Pages 584-593. 2. Bahrus D. Solar drian drying // Crops and soils. -№4 (30). - P.14-15. 3. Lowand T.A. Solar catined drues // Solar energy. - №4. -P.32-36. 4. Niles P.W., Carnegie E.J., Pohl J.G., Cherne J.M. Design and performance of an aircollector for indusrial croop dehydration // Solar energy. - №1 (20). -P.19-23. 5. Norkulova K.T., Iskandarov Z.S., Jumaev B.M. Issledovanie kombinirovannoy sushilnoy ustanovki. International Scientific Conference Innovation Tashkent 2016. P. 96-97. 6. Bala B. et al. Solar drying of pineapple using solar tunnel dryer Renewable Energy, 2003. Vol. 28. p. 183-190. 7. Safarov J.E., Sultanova Sh.A., Jumaev B.M. Texnologicheskiy protsess proizvodstva sushenyx lekarstvennyx trav. // Vestnik TashGTU, №2. 2015. S.164-167. 50

№ 5 (98) май, 2022 г. CHEMICAL ENGINEERING DOI - 10.32743/UniTech.2022.98.5.13817 SYSTEMATIC ANALYSIS AND MATHEMATICAL MODELING OF ULTRASONIC EXTRACTION PROCESS Asqar Artikov Dr, prof., Tashkent Chemical-Technological Institute, Republic of Uzbekistan, Tashkent Eldor Sakhatov Master student of the Tashkent Chemical-Technological Institute, Republic of Uzbekistan, Tashkent Sitorabonu Khudoyberdiyeva Master student of the Tashkent State Technical University, Republic of Uzbekistan, Tashkent E-mail: [email protected] Azamat Usenov Resercher of the Faculty of Machine building, Tashkent State Technical University named after Islam Karimov, Republic of Uzbekistan, Tashkent E-mail: [email protected] СИСТЕМАТИЧЕСКИЙ АНАЛИЗ И МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ПРОЦЕССА УЛЬТРАЗВУКОВОЙ ЭКСТРАКЦИИ Артиков Аскар д-р техн. наук, проф., Ташкентский химико-технологический институт, Республика Узбекистан, г. Ташкент Сахатов Эльдор магистрант Ташкентского химико-технологического института, Республика Узбекистан, г. Ташкент Худойбердиева Ситорабону Фарход кизи магистрант Ташкентского государственного технического университета, Республика Узбекистан, г. Ташкент Усенов Азамат соискатель машиностроительного факультета, Ташкентский государственный технический университет Республика Узбекистан, г. Ташкент ABSTRACT Systematic analysis of extraction allows a complete study of the object as a system, to determine the input and output parameters of the process and their interaction, and as a result to find the right solution. Initially, the object of research was to classify medicinal plants as a single system (single hierarchical level). Taking the following assumptions, we __________________________ Библиографическое описание: SYSTEMATIC ANALYSIS AND MATHEMATICAL MODELING OF ULTRASONIC EXTRACTION PROCESS // Universum: технические науки : электрон. научн. журн. Artikov A. [и др.]. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13817

№ 5 (98) май, 2022 г. construct a mathematical model of mass transfer in the inner and middle quasi layers of a particle, as well as in quasi layers in direct contact with the solvent. It is known that in the quasi layers of the leaves of the mint plant, the substance passes through molecular diffusion to the surface in contact with the solvent. АННОТАЦИЯ Системный анализ добычи позволяет всесторонне изучить объект как систему, определить входные и выход- ные параметры процесса и их взаимодействие и в результате найти правильное решение. Изначально объектом исследования была классификация лекарственных растений как единой системы (единого иерархического уровня). Принимая следующие допущения, построим математическую модель массопереноса во внутреннем и среднем квазислоях частицы, а также в квазислоях, непосредственно контактирующих с растворителем. Из- вестно, что в квазислоях листьев растения мяты вещество переходит путем молекулярной диффузии на поверх- ность, контактирующую с растворителем. Keywords: modeling, systematic analysis, ultrasonic, extraction, hierarchical scheme Ключевые слова: моделирование, систематический анализ, ультразвук, извлечение, иерархическая схема ________________________________________________________________________________________________ The proposed method of systematic thinking of the depending on the level of need for decision-making and object of obtaining medicinal plants, which we offer, al- research capabilities [2]. lows you to easily analyze the system of isolation of me- dicinal plants in the installation of existing methods [1]. The process of obtaining medicinal plants can be di- According to the proposed method, first of all, the in- vided into 3 stages [1,2,3]: dicators - the object of separation of medicinal plants - the extraction system and the input and output parameters 1) \"internal diffusion\", which includes all the phe- of the process that takes place at the object of separation nomena of transfer of substances within the raw material of medicinal plants are determined. The system under particles (penetration of the solvent into the pores of parti- consideration in the device (element) for the production cles of plant materials; melting of the component); of medicinal plants is then divided into components, the parameters for each selected element and the process 2) direct distribution of the substance within the in the element are indicated. And similarly, the division boundary layer; of an element (a plant extraction system in an extraction plant) into subsequent systems is not limited. Optimal 3) The passage of the extracted substance through the extraction of medicinal plants in the device was performed shell of the moving extractant and its distribution through- out the entire extractor mass (convective diffusion). For mathematical modeling of the process, we de- termined the input and output parameters of the plant ex- traction process. Fig. 1 shows a level 1 diagram of the hierarchy of medicinal plants. Figure 1. Level 1 hierarchical scheme of plant separation The main input parameters at this level are: (valuable components) in the apparatus over time; мerit2 - solvent output consumption. M - mass of raw material; ат - valuable components of raw materials; мerit - the mass of the solvent; аerit - The block diagram of the laboratory experimental the concentration of the solvent; Тerit - solution temperature. equipment and the computer model of the process of ob- Output parameters are as follows: тм - the mass of the remaining medicinal plants; ам - valuable components of taining a valuable component from the leaf of the mint medicinal plant residues; а(τ) - change in concentration plant are as follows: 52

№ 5 (98) май, 2022 г. y0 y 0 0.097130965656529 y2 X x0 x2 x x Scope x4 m0r Gr F1 m0r y m0 m0 0.23959106815255 i2 Y ekstraktor Figure 2. Structural diagram of laboratory and experimental equipment and computer model of the process of obtaining a valuable component from the leaves of the mint plant The structure of the holes in many ways affects the as well as in the quasi layers in direct contact with the extraction mechanism and the speed of its flow. The par- solvent. It is known that in the quasi layers of the leaves ticle size of a mint leaf is much larger than the diameter of the mint plant, the substance passes through the of the pores, so they can be obtained as isotropic porous molecular diffusion to the surface in contact with the bodies. Let us assume another: the extracts obtained are solvent. a group of components with different diffusion and physicochemical properties. Equation of material equilibrium in the middle quasi layer of a particle: In a one-dimensional system with a concentration gradient x dc/dx, the rate of change in the concentration dM mas3 = Gqk 3 − Gsarf 3 (3) of a substance at a given point depends on the diffusion dt and is determined by Fick's [3] second law. The result of Fick's second law is a second-order diffusion equation: Here Gqk3 is the arrival of a valuable component in the quasi-layer of the leaf particle of the mint plant ������с = ������ ���������������2������2���, (1) (m3 / s); Gsarf3 is the consumption of the valuable ������������ component through the quasi-layer of the mint particle, (m3 / s). where t is the time and x is the thickness coordinate of the mint leaf. It is known that the amount of Mmas3 valuable component passing through the middle quasi-layer to the Or the time distribution of the concentration of ex- outer layer is equal to the product of the amount of Mqk3 tractives in the particle size of a mint leaf is written by solution passing through this layer to the concentration the equation: of the valuable component in this layer amas3: ������с = ������ (���������������2������2��� + ������2������ + ������������2���������2���), (2) ������������������������3 = ������������������3 ⋅ ������������������������3 (4) ������������ ������������2 Such an equation has been solved by scientists to In this case: linearly describe the initial conditions. In the actual pro- cess, the initial conditions, in particular the distribution ������(������������������3⋅������������������3) = ������������������ 3 − ������������������������������ 3 (5) of the concentration of the crushed mint leaf in the body, ������������ are related to taking into account the concentration of the valuable component in the external environment, which The following is an analysis of a mathematical changes over time. The order of derivation of computa- expression describing a change in the concentration of a tional equations, there are also large errors in the appli- valuable component in a solution: cation of the third type of boundary conditions. da3 = 1  (Gqk3 − Gsarf 3 ) (6) Therefore, the development and application of com- dt m3 putational solutions based on multi-stage computer modeling techniques will be more optimal. it begins The results of experiments conducted on a computer with modeling the distribution of concentration within a model of the process of extraction of extractive substances body of material. from mint analyzed the changes in the concentration in the solvent and quasi-layers (Fig. 3). It is known that Modeling of the extraction process in quasi-layers over time, the concentration of the valuable component of a material particle. Taking the above assumptions, from each layer decreases. we construct a mathematical model of the mass transfer in the inner and middle quasi layers of the particle, 53

№ 5 (98) май, 2022 г. Figure 3. Change of the concentration of the valuable component in the solid phase quasi-layers with diffusion coefficient D=0,7∙10-11 m2/s (decrease in the concentration of the valuable component) As can be seen from Fig. 3, intensive extraction of coefficient over time in the study does not contradict extractives from the raw material continued for 3000 s modern ideas about the mechanism of obtaining a po- from open holes and capillaries. Subsequently, the pro- rous structure from plant raw materials. cess proceeded more slowly and approached equilib- rium after 8100 s. The nature of the change in diffusion Список литературы: 1. Султанова Ш.А., Усенов А.Б. Получение данных температурной зависимости растворимости спирта при экс- тракции растения базилика обыкновенного (ocimum basilicum). // Universum: технические науки: электрон. научн. журн. 2020. 11(80). 2. Yoo C.K., Lee J.M. and Lee I.B. Nonlinear Model-based Dissolved Oxygen Control in a Biological Wastewater Treatment Process // Korean J. Chem. Eng., 21(1), 14 (2004). 3. Kitanovic S., D. Milenovic, Veljkovic V.B. Empirical kinetic models for the resinoid extraction from aerial parts of St. John’s wort (Hypericum perforatum L.) Biochemical Engineering Journal. – 2008. – V. 41. – P. 1. 54

№ 5 (98) май, 2022 г. DOI - 10.32743/UniTech.2022.98.5.13700 USE OF PHOSPHOGIPS IN SILICATES Abdulaziz Khokimov Assistant of “Chemical technology” Chair, Fergana Polytechnic Institute, Uzbekistan, Ferghana E-mail: [email protected] ИСПОЛЬЗОВАНИЕ ФОСФОГИПСОВ В СИЛИКАТАХ Хокимов Абдулазиз Эргашали угли ассистент кафедры «Химическая технология», Ферганский политехнический институт, Республика Узбекистан, г.Фергана ABSTRACT Today, as in the rest of the world, our country needs to use waste as secondary raw material. Of course, this is due to the growing demographics and the declining supply of ore-rich raw materials. In this era of trends, finding helpful solutions for the use of phosphogypsum and its introduction into the industry is always relevant. Here are some results of this problem and discuss the possibilities of using world experience. АННОТАЦИЯ Сегодня, как и во всем мире, наша страна нуждается в использовании отходов в качестве вторичного сырья. Это, конечно, связано с ростом демографии и сокращением поставок богатого рудой сырья. В эту эпоху тенденций поиск эффективных решений по использованию фосфогипса и внедрение его в промышленность всегда актуальны. Приведем некоторые решения этой проблемы и обсудим возможности использования мирового опыта. Keywords: phosphoric acid, wet process, phosphogypsum, compost, ceramic filler. Ключевые слова: фосфатная кислота, мокрый способ, фосфогипс, компостирование, керамический наполнитель. ________________________________________________________________________________________________ Phosphoric acid (H3PO4) is produced from phosphate disposed of without any processing, mainly by disposing ores by wet or thermal methods. The world’s 80% of of large stocks. These areas are usually located in areas phosphoric acid obtained by the wet process. The wet close to phosphate acid plants, which occupy large areas method involves chemical reactions, filtration, and evapo- of land and cause serious damage to the environment. ration (increasing the concentration). The phosphate rock Phosphogypsum is mainly composed of gypsum, but also is first ground and mixed with sulfuric acid in a reactor contains high levels of compounds such as phosphates, vessel. As a result of the reaction, tricalcium phosphate fluorides and sulfates, natural radionuclides, heavy of the phosphate rock convert into phosphoric acid and an metals, and other trace elements. All this hurts the envi- insoluble salt called gypsum, calcium sulfate (CaSO4). ronment and places many restrictions on the widespread use of PG. Up to 15% of PG in the world is used as Ca5(PO4)3F + 5H2SO4 + nH2O = additional raw material in the production of building 5CaSO4∙nH2O + 3H3P04 + HF↑ materials, soil modification, and the production of Keeping the concentration of sulfuric acid at Portland cement (Table 1,). In particular, the use of PG 93-98% affects the reaction rate and crystallization of is prohibited in many countries. The US Environmental gypsum. In addition, controlling the concentration of Protection Agency classifies PG as a “Technologically sulfuric acid reduces the energy demand for evaporation Enhanced Naturally Occurring Radioactive Material” [2]. and ensures optimal production. Radioactive substances found in nature are found The next step is filtration, in which solids are sepa- everywhere throughout the earth's crust; mining, ore rated and washed. Finally, the extract is evaporated to processing, fuel extraction, and other industries. The obtain commercial phosphate acid. High levels of phos- presence of radioactivity in the waste increases the risk phoric acid used in the food, pharmaceutical, and cos- of human exposure. The chemical industry can emit metic industries will need to be refined [1]. The produc- large amounts of radioactive substances into the envi- tion of phosphoric acid from natural phosphate rock by ronment, which leads to the spread of radiation. These the wet method results in an industrial by-product industries include mining, phosphate processing, metal called phosphogypsum (PG). The production of one ton ore processing, heavy mineral sand processing, pigment of phosphoric acid produces about 5 tons of PG and production, fuel extraction and combustion, construc- provides an increase in PG reserves worldwide of tion materials, thorium compounds production, aviation, 100-280 million tons per year. This additional product is and scrap metal processing [3]. __________________________ Библиографическое описание: Khokimov A.E. USE OF PHOSPHOGIPS IN SILICATES // Universum: технические науки : электрон. научн. журн. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13700

№ 5 (98) май, 2022 г. Chemical composition of raw materials in cement production [4] Table 1. Components Phosphogypsum Shale Limestone CaO 30,45 5,05 50,81 SiO2 9,50 35,34 7,67 Al2O3 2,80 14,21 2,41 Fe2O3 0,90 5,23 1,15 SO3 42,9 0,15 0,26 MgO 0,30 1,88 0,57 K2O 0,10 0,30 0,16 P2O5 0,63 0,11 0,29 LOI 12,42 37,73 36,68 In many coastal countries, industrial by-products were added in conjunction with PG and the experimental are located along the coast, resulting in marine changes. inspection determined the optimal amount of water, fiber Phosphogypsum is also a solid by-product formed in the content, compression pressure, and compression num- production of phosphoric acid using similar traditional ber. Using an intermittent pressurized hydration process, synthesis methods. Dissolution of raw phosphorite, phosphogypsum and fiberglass-based non-combustible which is about 50 times more radioactive than ordinary tiles were produced for optimal ratios. The mechanical soils, in dilute sulfuric acid produces the primary product, and durability properties of the phosphogypsum and phosphoric acid, and additional phosphogypsum. Reactive fiberglass coated tile were tested. The main component hazardous elements and natural radionuclides bind to PG. of PG is CaSO4 • 2H2O, which is well compatible with An insignificant portion of PG is in the form of nanopar- glass fiber in the hydration process. Phosphogypsum ticles (<0.1 μm). However, PG is a harmful by-product and fiberglass-based tiles have also been found to be in many countries [5]. slightly more acid-resistant than traditional tiles. [7]. Due to the high content of phosphate, sulfate, and In addition to the above, PG can be used as addi- calcium in phosphogypsum, there have been several at- tional raw material and filler in many other areas. Exam- tempts to change it from soil to soil. In particular, ples, the use of phosphogypsum to improve the sorption PG was used in composting. Composts are produced by capacity of ceramic composites, the use of clay as a mixing olive oil and coffee bean waste into PG. binder, and the use of ceramic glass [8]. Two concentrations of PG were tested, and composts formed after fermentation were used in field experiments In short, the efficient and economical use of indus- to grow potatoes. The plants were grown in the field trial waste is a task of economic and social importance. and composts were added as fertilizer and compared At present, the use or recycling of phosphogypsum re- to commercial compost and cattle manure. Yields of mains a problem for new or existing chemical plants. potatoes grown in composts with the addition of phos- Although a lot of scientific research has been done in the phogypsum increased by 55.17% and were recommended field of complex processing of raw materials and some for use in the production of high-quality food products [6]. achievements have been made, the problem of using phosphogypsum is still on the agenda. Many world ex- There are also opportunities to use PG in the produc- periments using PG have been discussed and analyzed tion of environmentally friendly non-combustible ceramic above, and the results have been presented. Of course, it wall tiles. In particular, the possibility of using phos- is not possible to use them 100%, but it is advisable to phogypsum as a binder in ceramic tiles is given below. apply them to the development of the most effective so- To increase the bending strength of the slab, glass fibers lutions. References: 1. A.A. Ismatov, T.A. Otaqo’ziyev, N.P. Ismoilov, F.M. Mirzayev. “Noorganik materiallar kimyoviy texnologiyasi”. “O’zbekiston”, Toshkent-2002, 321. 2. Tayibi H, Choura M, López FA, Alguacil FJ, López-Delgado A. Environmental impact and management of phos- phogypsum. J Environ Manage. 2009 Jun;90(8):2377-86. doi: 10.1016/j.jenvman.2009.03.007. Epub 2009 Apr 29. PMID: 19406560. 3. Vearrier D, Curtis JA, Greenberg MI. Technologically enhanced naturally occurring radioactive materials. Clin Toxicol (Phila). 2009 May;47(5):393-406. doi: 10.1080/15563650902997849. PMID: 19492930. 4. Addi, K. & Diouri, A. & Khachani, Nacer & Boukhari, A.. (2018). Mineralogical stabilization of Ternesite in Belite Sulfo-Aluminate Clinker elaborated from limestone, shale and phosphogypsum. MATEC Web of Conferences. 149. 01073. 10.1051/matecconf/201714901073. 56

№ 5 (98) май, 2022 г. 5. Silva LFO, Oliveira MLS, Crissien TJ, Santosh M, Bolivar J, Shao L, Dotto GL, Gasparotto J, Schindler M. A review on the environmental impact of phosphogypsum and potential health impacts through the release of nanoparticles. Chemosphere. 2022 Jan;286(Pt 1):131513. doi: 10.1016/j.chemosphere.2021.131513. Epub 2021 Jul 9. PMID: 34284899. 6. Kammoun M, Ghorbel I, Charfeddine S, Kamoun L, Gargouri-Bouzid R, Nouri-Ellouz O. The positive effect of phosphogypsum-supplemented composts on potato plant growth in the field and tuber yield. J Environ Manage. 2017 Sep 15;200:475-483. doi: 10.1016/j.jenvman.2017.06.016. Epub 2017 Jun 13. PMID: 28622650. 7. Arunvivek, G.K., Rameshkumar, D. Experimental Investigation on Feasibility of utilizing Phosphogypsum in E-Glass Fiber-incorporated Non-fired Ceramic Wall Tile.J. Inst. Eng. India Ser. A(2022). https://doi.org/10.1007/s40030- 021-00604-2 8. Sh.Sh.Xamdamova, S.R.Mirsalimova, A.E.Xokimov. Fosfogipsdan keramik-shisha tayyorlash. «Инновационные разработки и перспективы развития химической технологии силикатных материалов» посвященная 90-летию со дня основания лаборатории Химии и химической технологии силикатов АН РУз, памяти заслуженного деятеля науки Узбекистана, д.х.н., проф. Н.А. Сиражиддинова и приуроченный Международному году «Стекло-2022». Toshkent, 2022y, 282-284. 57

№ 5 (98) май, 2022 г. DOI - 10.32743/UniTech.2022.98.5.13640 PRODUCTION OF POLYETHYLENE TEREPHTHALATE Zuhriddin Rayimov Assistant, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara E-mail: [email protected] Niginabonu Jamilova Assistant, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara E-mail: [email protected] ПРОИЗВОДСТВО ПОЛИЭТИЛЕНТЕРЕФТАЛАТА Райимов Зуҳриддин Хайриддин угли ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара Жамилова Нигинабону Кобил кизи ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара ABSTRACT The article analyzes the methods of obtaining polyethylene terephthalate from petroleum and coke chemical pro- cessing products, which play a leading role in the creation of a new generation of polymer materials in the polymer industry. АННОТАЦИЯ В статье проанализированы способы получения полиэтилентерефталата из продуктов переработки нефти и коксохимии, играющие ведущую роль в создании полимерных материалов нового поколения в полимерной про- мышленности. Keywords: polyethylene terephthalate (PETP,PET), terephthalic acid (TPA), ethyleneglycol (EG), esterification, diethylene glycol (DEG), isophthalic acid (IPA), thixotrope, monoglycol ether, diglycol ether Ключевые слова: полиэтилентерефталат (ПЭТФ, ПЭТФ), терефталаткислота (ТФК), этиленгликоль (ЭГ), этерификация, диэтиленгликоль (ДЭГ), изофталевая кислота (ИФК), тиксотроп, моногликольэфир, дигликоль- эфир. ________________________________________________________________________________________________ The chemistry and technology of polymeric materi- Polyethylene terephthalate (PETP, PET) is a satu- als is an important technology of modern development, rated polyester based on ethylene glycol and terephthalic and the possibility of obtaining new properties of mate- acid. rials based on a given combination of known polymers is very important. The production of polyethylene terephthalate is based on the direct esterification of TPA with ethylene Today, in the polymer industry, the creation of a glycol and the subsequent polycondensation of the re- new generation of polymer materials based on the sulting diglycol ether to form a high molecular weight achievements of innovative technologies in world prac- polyester. tice is leading. The scheme of obtaining PETP from petroleum and coke chemical refining products can be summarized as follows (Figure 1) __________________________ Библиографическое описание: Rayimov Z.X., Jamilova N.Q. PRODUCTION OF POLYETHYLENE TEREPHTHALATE // Universum: технические науки: электрон. научн. журн. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13640

№ 5 (98) май, 2022 г. Figure 1. General connection scheme for PETP PETP production raw materials in the presence of catalysts (cobalt and manganese acetates) and promoters (bromine, mainly sodium The main raw materials for the production of PETP bromide-containing compounds). The solvent in this are terephthalic acid and ethylene glycol. They are de- rived from petroleum and coke chemical products. case is actively involved in the oxidation process. Acetic acid activates oxygen, shortens the induction period and Terephthalic acid is a crystalline substance that is less increases the rate of formation and decomposition of soluble in water and organic liquids than dicarboxylic hydroperoxides. acids (phthalic acid and isophthalic acid), which are isomers to it. Changes in the oxidation of p-xylene occur in the following sequence (Figure 2): p-xylene 1 → p-toluene Terphthalic acid is oxidized to p-xylene. P-xylene is acid 2 → p-toluene acid 3 → p-carboxybenzaldehyde 4 → obtained by catalytic reforming of the gasoline fraction. p-benzoldicarboxylic acid (TPA) Oxidation of P-xylene is carried out in air in a solution of acetic acid at a pressure of 125–2750C and up to 40 atm CH3 CH3 CH3 CHO COOH CH3 CHO COOH COOH COOH 1 23 4 TPA Figure 2. Sequence of changes in the oxidation of p-xylene Ethylene glycol is a hygroscopic, odorless liquid Direct oxidation of ethylene glycol with air or pure with a clear colorless light oily consistency when puri- oxygen in a silver catalyst to ethylene oxide, followed fied. It mixes with water, various alcohols, acetone, by hydration of ethylene oxide at 10 atm and in the pres- glycerin in different proportions, is insoluble in aromatic ence of 0.1-0.5% sulfuric and orthophosphate acids is hydrocarbons, chloroform, carbon sulfide. obtained by. (Figure 3) 59

№ 5 (98) май, 2022 г. H2C CH2 O2 CH2 + H2O H+ HO CH2CH2 OH cat H2C  O Figure 3. Ethylene glycol extraction reactions from ethylene Hydration is carried out with a large amount of ex- Diethylene glycol (DEG) gives polyester its elasticity cess water to minimize the formation of other glycols. and clarity properties. Isophthalic acid (IPA) prevents When the reaction is carried out within 1 hour, the yield premature crystallization when blowing products from of ethylene glycol reaches ~ 90%. preforms, which reduces the breakdown of items from cracking. Small amounts of diethylene glycol and isophthalic acid are used as modifiers in the esterification and The general formula of the modified PETF is shown pre-polycondensation stages of PETP to form specific in figure 4. properties [1]. Figure 4. General formula of modified polyester: x- amount of IFK,% mass; y - amount of DEG,% mass; p- degree of polycondensation. The process of obtaining PETP consists of two main Properties of preparation of TPA suspension stages: in ethylene glycol 1 - esterification stage; 2 - polycondensation stage. In ethylene glycol, the TPA suspension is prepared in a molar ratio of EG: TFK 1: 1 to 2: 1. For convenience, Etherification of terephthalic acid with ethylene glycol we denote the ratio of goods by the Latin letter ƒ. For ex- ample, when ƒ = 2, 2 moles of ethylene glycol in suspen- Etherification of terephthalic acid with ethylene gly- sion with a concentration of TFK of 57.23% (Table 1). col is carried out by the continuous method at a temper- ature of 280 - 2850C by delivering a pre-prepared sus- pension of TPA in ethylene glycol to the reactor-esteri- fier, adding to the TPA as a modifier in the amount of isophthalic acid (2.0 ± 0.1)%. swells. Characteristics of TPA suspensions in ethylene glycol Table 1. EG: TFK mole Suspension composition,% mass. Density 200C Carboxylic number, ratios * mg-eq / kg ƒ TPA ethyleneglycol 8763,66 1:1 8531,33 1,1 : 1 1 72,80 27,20 1,3775 8312,24 1,2 : 1 8102,78 1,3 : 1 1,1 70,87 29,13 1,3690 7904,15 1,4 : 1 7713,95 1,5 : 1 1,2 69,05 30,95 1,3610 7534,58 1,6 : 1 7362,44 1,7 : 1 1,3 67,31 32,69 1,3535 7197,52 1,8 : 1 7041,03 1,9 : 1 1,4 65,66 34,34 1,3465 6889,35 2:1 1,5 64,08 35,92 1,3398 1,6 62,59 37,41 1,3336 1,7 61,16 38,84 1,3276 1,8 59,79 40,21 1,3220 1,9 58,49 41,51 1,3167 2 57,23 42,77 1,3116 60

№ 5 (98) май, 2022 г. During preparation, the density of the suspension glycol between the particles (network nodes). If such a is calculated according to the formula: suspension is constantly stirred, it will have the appearance of a viscous liquid. If mixing is stopped, the suspension Cj . C t will not flow for some time due to the internal structure Csp = ct − Cm . Dc of the solid phase particles. If this happens in a large- capacity device, it can still be mixed. In practice, the Here drive reducer often breaks when the agitator is started. Cj is the density of the liquid, kg / m3; Csp - suspension density, kg / m3; Heating this suspension reduces the likelihood of Dc - space density difference, kg / m3; structuring and makes it easier to mix and blend and Ct - solid phase density, kg / m3; drive. Cm is the percentage of solid phase in the suspen- sion. Suspensions are often thixotropic fluids. ƒ=2 The suspension retains its fluidity and can be These fluids are fluids whose shear stress decreases driven by special pumps. Other ratios ƒ = 1.3–1.6 can also over time at constant rates of deformation. Thixotropic be used. Such suspensions, which retain a large amount fluids are able to restore their structure after removing of solid phase at low internal friction stresses, do not the external force that causes leakage. leak, only change their shape. When the internal friction In practice, the suspension is prepared by mixing force is higher than a certain value, the suspension starts TFK with ethylene glycol at 110–1600C and ƒ = 1.6–1.8. to flow. This creates a technological reserve of suspension for Suspensions that retain large amounts of solid phase 4-5 hours. At the same time, the suspension is stirred are structured over time. The structuring process is continuously and heated to maintain the set temperature. caused by the presence of TPA microparticles in the chain, Heating the suspension initiates the esterification re- which in turn form spatial three-dimensional networks action. For example, at 1400C, the suspension begins to (networks). The higher the solid phase concentration, lose its fluidity after 3 hours. At 130℃, this process the smaller the network cell and the stronger the network takes much longer, about 12 hours. Under these condi- as a whole. In the cells there is a liquid phase - ethylene tions, the esterification of TPA is shown in figure 5. COOCH3 COO CH2 CH2 OH + 3 HO CH2CH2 OH + COOCH3 COOH TPA monoglycol ether COO CH2 CH2 OH + + 3 H2O COO CH2 CH2 OH diglycol ether Figure 5. Etherification of TPA ƒ˂2 insufficiency of ethylene glycol relative to the which exhibits thixotropic fluid properties of non-New- stoichiometric amount leads to incomplete conversion tonian viscous fluid with non-Newtonian viscous fluid of TPA, ie the formation of a mixture of mono- and properties. diglocol esters. 2) At rest, the suspension can be structured and re- From the above, the following conclusions can be quires external force to disrupt its internal structure drawn. to create flexibility. 1) When preparing a mixture of TPA in EG, a sus- 3) In the preparation of a suspension of TPA in EG, pension can be formed in the range of values ƒ = 1 ÷ 2, an esterification reaction is initiated at a temperature 61

№ 5 (98) май, 2022 г. of 110 ℃ and above. This reaction is maintained until reduction in particle size occurs due to the esterification the hydrolysis reverse reaction with water is reached to reaction that occurs on the surface of TPA crystals, a steady state. which results in a reduction in their size. 4) When the suspension is kept in a stirred state for 5) The processes that take place during the preparation a long time, the solid phase does not break down as a of the suspension of TPA in EG do not lead to a defec- result of mechanical action on the TPA particles. The tive product (waste) in the later stages of production. Reference: 1. ОгрельЛ.Д. Оценка накопления, сбора и переработки отходов ПЭТФ в России // Экологический вестник России. – 2012. - №4 – с. 34. 2. O’G’Li, Rayimov Zuhriddin Khayriddin, and Jamilova Niginabonu Qobil Qizi. \"ANALYSIS OF IMPORTANCE AND METHODS OF PRODUCTION OF BLOCK SOPOLYMERS BASED ON POLYETYLENTEREPHTALATE.\" International Journal of Advanced Technology and Natural Sciences 3.1 (2022): 51-55. 3. Жамилова Н.К.К., Зарипов М.Х.У., & Мирзаев С.С. (2017). Изучение процесса регенерации цеолитовой очистки природного газа на УДП\" Шуртаннефтгаз\". Вопросы науки и образования, (2 (3)), 45-47.Жамилова, Н.К.К., Зарипов, М.Х.У., & Мирзаев, С.С. (2017). Изучение процесса регенерации цеолитовой очистки при- родного газа на УДП\" Шуртаннефтгаз\". Вопросы науки и образования, (2 (3)), 45-47. 4. Rayimov, Z.X. O.G. L. (2021). Ftal angidridning vinillanish jarayoni erituvchilari. Science and Education, 2(12), 266-269. 5. Ахмедов, Вохид Низомович, Бобир Баходир Угли Олимов, and Шомурод Комилович Назаров. \"Электронная структура и квантово-химические расчёты виниловых эфиров фенолов.\" Universum: химия и биология 4 (70) (2020). 62

№ 5 (98) май, 2022 г. DOI - 10.32743/UniTech.2022.98.5.13712 MECHANISMS OF ETERIFICATION OF TEREFTALIC ACID WITH ETYLENGLYCOL Zuhriddin Rayimov Assistant, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara E-mail: [email protected] Niginabonu Jamilova Assistant, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara E-mail: [email protected] Aminjon Voxidov Student, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara Temurbek Dusiyorov Student, Bukhara Institute of Engineering and Technology, the Republic of Uzbekistan, Bukhara МЕХАНИЗМЫ ЭТЕРИФИКАЦИИ ТЕРЕФТАЛЕВОЙ КИСЛОТЫ ЭТИЛЕНГЛИКОЛЕМ Райимов Зуҳриддин Хайриддин угли ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара Жамилова Нигинабону Кобил кизи ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара Вохидов Аминжон Олимович студент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара Дусиёров Темурбек Рузимурод угли студент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара ABSTRACT The article presents the mechanisms of the reaction of esterification of terephthalic acid with ethylene glycol, the effects of the chemical structure of the catalyst on the rate constant of the esterification reaction, and the analysis of changes in the number of unresponsive groups during esterification using different catalysts. АННОТАЦИЯ В статье описаны механизмы реакции этерификации терефталевой кислоты этиленгликолем, влияние хими- ческого строения катализатора на константу скорости реакции этерификации, а также анализ изменения количе- ства нереагирующих групп при этерификации с использованием различных катализаторы. __________________________ Библиографическое описание: MECHANISMS OF ETERIFICATION OF TEREFTALIC ACID WITH ETYLENGLYCOL // Universum: технические науки : электрон. научн. журн. Rayimov Z.X. [и др.]. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13712

№ 5 (98) май, 2022 г. Keywords: polyethylene terephthalate (PETP,PET), terephthalic acid (TPA), ethyleneglycol (EG), esterification, tet- rabutoxytitanium, lead dibutyl phthalate, nucleophilic component, sulfuric acid. Ключевые слова: полиэтилентерефталат (ПЭТФ, ПЭТФ), терефталаткислота (ТФК), этиленгликоль (ЭГ), этерификация, тетрабутоксититанат, дибутилфталат свинца, нуклеофильный компонент, серная кислота. ________________________________________________________________________________________________ Analyzing the esterification reaction of terephthalic acid with ethylene glycol (Figure 1). COOH COO CH2 CH2 OH + 2 HO CH2CH2 OH + 2 H2O COOH COO CH2 CH2 OH Figure 1. Etherification reaction of terephthalic acid with ethylene glycol Etherification processes are usually carried out in The catalytic activity of strong acids is very large. the presence of catalysts. In practice, acid catalysts (sul- When used, the reaction rate increases by more than 30 furic acid, p-toluene sulfoxic acid, etc.) and amphoteric times. This can be seen in the example of the values of catalysts (tetrabutoxytitanate, lead dibutylphthalate, etc.) the rate constants of the reaction of esterification of TPA are used. Sometimes the process is done without with diol in their presence. Table 1 shows the effect of a catalyst. the chemical structure of the catalyst on the rate constant of the esterification reaction. Table 1. The effect of the chemical structure of the catalyst on the rate constant of the esterification reaction Catalyst Reaction rate constant с·108 g – equiv / (g s) Without catalysts 7,8 Sulfuric acid 263,0 Antimony acid 25,6 Tetrabutoxytitanat 30,2 Lead dibutyl phthalate 22,6 However, when strong acids are used in practice as resulting in an unacceptable amount of diethylene glycol catalysts, they complicate the process due to their sim- of 3-5%. Large amounts of 1,4-dioxane were found in ultaneous catalytic acceleration of additional reactions the by-products of the reaction. and their interaction with the initial and final products. For example, sulfuric acid sulfates the products of the On fig. 2 is a graphical representation of the number reaction at high temperatures. Similarly, it catalyzes the of unreacted carboxyl groups as a function of the cata- intermolecular dehydration reaction of ethylene glycol, lyst used. 64

№ 5 (98) май, 2022 г. 1- without catalyst; 2- antimony acid; 3- lead dibutyl phthalate; 4- tetrabutoxytitanate; 5- sulfuric acid. Figure 2 Change in the number of non-reactive groups during esterification using various catalysts (% of the mass of TFA). T=230℃ When the temperature rises above 230 ℃, the reaction case, the role of the catalyst is played by the ion pair - rate rises to such an extent that it can be carried out with- TPA dimer, which is formed by autoprolysis of TPA. out an external catalyst, but with a rapid release of water. The reaction mechanism is shown in fig. 3 and is in To synthesize PETP, TPA undergoes a reaction to good agreement with classical ideas about the process of obtain diglycol ester without an external catalyst. In this esterification of carboxylic acids with alcohols. COOH HO 2 HOOC COO ... C COOH HO COOH 1 HO COOH HOOC OH TFK C 2 C HO OH OH HO CH2 CH2 OH HOOC C OH TFK O CH2CH2 OH - H2O 3 65

№ 5 (98) май, 2022 г. OH HOOC OH C C TFK HOOC O CH2CH2 OH O CH2CH2 OH 4 5 HO O C C O CH2CH2 OH HO 6 HO O TFK C C O CH2CH2 OH HO 7 HO O HO CH2 CH2 OH HO C C O CH2CH2 OH TFK O H CH2CH2 OH 8 - H2O HO O C C O CH2CH2 OH HO CH2 CH2 O 9 HO O C O CH2CH2 OH TFK HO CH2 CH2 C O 10 66

№ 5 (98) май, 2022 г. O O -H C O CH2CH2 OH + TFK HO CH2 CH2 O C 11 Figure 3. Mechanisms of the esterification reaction of carboxylic acids with alcohols Due to autoprolysis, the protonation of the oxygen In order to reach the end of the reaction, water must atom of the carbonyl group of TPA 1 occurs. The proto- be expelled from the reaction area, if no water is expelled, nated molecule carrying the positive charge then undergoes an equilibrium state is created and the reaction stops a polycondensation reaction with 1 EG. In the scheme, before it reaches the end. The release of water acceler- the structures (1,2,3,4,5 and 6,7,9,10) interconnected by ates the reaction and shifts the equilibrium towards the a sharp arrow on both sides are considered saturated. formation of TPA esters. Their rate of transition is so great that they can be detected spectroscopically as if they existed at the same time. The esterification is carried out using a continuous However, only carbokation (electrophilic) 2 and 7 are method by delivering a suspension of TPA in the EG to attacked by the nucleophilic component (EG). The re- the reaction area and bringing the esterification to the sulting structure redirects the proton within 5 molecules, polycondensation stage. The process is so rapid that the along with the positive charge, to the carbony oxygen atom TPA suspension has almost complete reaction from the of the empty carboxyl group. A protonated molecule of the point of its introduction into the reactor until the reaction second carbonyl group of TPA monoglycol ester 6 (7) is mass is removed from the apparatus circulation circuit. formed, which interacts with the next molecule of EG. (that is, the TPA does not remain in the etheric). The esterification process continues until the formation of diglycol ester of TPA 11. Reference: 1. Огрель Л.Д. Оценка накопления, сбора и переработки отходов ПЭТФ в России // Экологический вестник России. – 2012. - №4 – с. 34. 2. O’G’Li, Rayimov Zuhriddin Khayriddin, and Jamilova Niginabonu Qobil Qizi. \"ANALYSIS OF IMPORTANCE AND METHODS OF PRODUCTION OF BLOCK SOPOLYMERS BASED ON POLYETYLENTEREPHTA- LATE.\" International Journal of Advanced Technology and Natural Sciences 3.1 (2022): 51-55. 3. Жамилова Н.К.К., Зарипов, М.Х.У., & Мирзаев, С.С. (2017). Изучение процесса регенерации цеолитовой очистки природного газа на УДП\" Шуртаннефтгаз\". Вопросы науки и образования, (2 (3)), 45-47.Жамилова Н.К.К., Зарипов, М.Х.У., & Мирзаев, С.С. (2017). Изучение процесса регенерации цеолитовой очистки природного газа на УДП\" Шуртаннефтгаз\". Вопросы науки и образования, (2 (3)), 45-47. 4. Жумаев Ж.Х., Ахмедов В.Н. МЕХАНИЗМ ПОВЫШЕНИЕ АКТИВНОСТИ КАТАЛИЗАТОРА В ПРОЦЕССЕ АЛЛЕНЛИЗАЦИИ МОФОЛИНА ВИНИЛАЦЕТИЛЕНОМ //Universum: химия и биология. – 2022. – №. 3-2 (93). – С. 24-27. 5. Rayimov, Z.X.O.G.L. (2021). Ftal angidridning vinillanish jarayoni erituvchilari. Science and Education, 2(12), 266-269. 6. Ахмедов, Вохид Низомович, Бобир Баходир Угли Олимов, and Шомурод Комилович Назаров. \"Электронная структура и квантово-химические расчёты виниловых эфиров фенолов.\" Universum: химия и биология 4 (70) (2020). 7. Жумаев Ж.Х., Ахмедов В., Шарипова Н.У. ВЛИЯНИЕ ПРИРОДЫ И КОЛИЧЕСТВА КАТАЛИЗАТОРА ПРИ СИНТЕЗЕ МОРФОЛИНОВЫХ НЕНАСЫЩЕННЫХ ПРОДУКТОВ ПРИ УЧАСТИИ ВИНИЛАЦЕТИЛЕНА // Москва. – 2021. – С. 58-61. 8. Рахматов М.С. Влияние катализатора, температуры и растворителя на синтез и выход продукта реакции с виниловым эфиром салициловый кислоты в присутствии винилацетилена //Universum: химия и биология. – 2020. – №. 11-2 (77). – С. 16-20. 67

№ 5 (98) май, 2022 г. DOI - 10.32743/UniTech.2022.98.5.13592 ANALYSIS OF IMPORTANCE AND METHODS OF PRODUCTION OF BLOCK SOPOLYMERS BASED ON POLYETYLENTEREPHTALATE Zuhriddin Rayimov Assistant, Bukhara Institute of Engineering andTechnology, the Republic of Uzbekistan, Bukhara G-mail: [email protected] Niginabonu Jamilova Assistant, Bukhara Institute of Engineering andTechnology, the Republic of Uzbekistan, Bukhara E-mail: [email protected] АНАЛИЗ ЗНАЧЕНИЯ И СПОСОБОВ ПОЛУЧЕНИЯ БЛОК-СОПОЛИМЕРОВ НА ОСНОВЕ ПОЛИЭТИЛЕНТЕРЕФТАЛАТА Райимов Зуҳриддин Хайриддин угли ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара Жамилова Нигинабону Кобил кизи ассистент, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара ABSTRACT The article analyzes the importance and methods of obtaining polyethylene terephthalate-based copolymers, which play a leading role in the creation of a new generation of polymer materials with properties based on the achievements of innovative technologies in the polymer industry. АННОТАЦИЯ В статье анализируются значение и способы получения сополимеров на основе полиэтилентерефталата, играющих ведущую роль в создании полимерных материалов нового поколения со свойствами, основанными на достижениях инновационных технологий полимерной промышленности. Keywords: block copolymerization, copolyesters, antipyrenes, modifiers, hydroquinone, terephthalic acid, exchange bisphenols, polyethylene terephthalate Ключевые слова: блок-сополимеризация, сополиэфиры, антипирены, модификаторы, гидрохинон, терефталевая кислота, обменные бисфенолы, полиэтилентерефталат ________________________________________________________________________________________________ Today in the polymer industry in the world practice microphase layering, which eventually allows the is the creation of a new generation of polymer materials properties of the block-copolymers to combine in an odd with properties based on the achievements of innovative way. technologies. Depending on the chemical nature of the blocks, it The chemistry and technology of polymeric is possible to obtain structural and properties materials materials is an important technology of modern that differ significantly from the properties of the development, the search for the possibility of obtaining original component, depending on their length, number new properties of materials based on a given binding of and sequence of exchange. There is a great potential for certain polymers. this, and they are beginning to be realized. The most One of the interesting ways in this direction is the typical is the creation of thermoelastoplasts large-toned creation of block copolymers, the macromolecules of polymeric materials, the application of the principles of which are hybrids of blocks with different chemical block-copolymerization in their synthesis allowed to structure and composition. The thermodynamic combine the properties of thermoplastics and elastomers incompatibility of the blocks often leads to a solid in one material. The great potential of block copolymers __________________________ Библиографическое описание: Rayimov Z.X., Jamilova N.Q. ANALYSIS OF IMPORTANCE AND METHODS OF PRODUCTION OF BLOCK SOPOLYMERS BASED ON POLYETYLENTEREPHTALATE // Universum: технические науки : электрон. научн. журн. 2022. 5(98). URL: https://7universum.com/ru/tech/archive/item/13592

№ 5 (98) май, 2022 г. has led to a sharp increase in interest in them in recent phthalic acids and 3.5- dibromo-p-oxybenzoic acid years. chlorohydride and terephthaloid (p-oxybenzoic) acid groups have high mechanical and dielectric properties, At present, all the main problems of polymer high chemical and dielectric properties. In the synthesis physics and physical chemistry in the field of block of the mentioned polymers, the acceptor catalytic copolymer testing - the nature of polymer sequencing, method of polycondensation and the laws of high- phase separation properties in polymers and the temperature polycondensation were studied, the laws influence of basic molecular parameters, phase strength between the structure, composition and properties of the under temperature and force, physical and mechanical obtained polyesters were determined. The block properties of microphases and their role in these synthesized within the scope of this research - ceramic properties. being investigated. polyester and ceramic film can be used in various industries of modern industry (automotive - radio- There are some limitations and unresolved issues in electronic, electrical aviation, electronic, chemical, etc.) the field of synthesis, analysis, properties description as heat-resistant construction and film materials. and application of block copolymers. This provides a good incentive for intensive inspections, research and Synthesis of copolymers with polyethylene development of relevant industries. terephthalate (PETP) and other components of p- oxybenzoic acid can also be performed. It has been The following three methods are the most preferred found that when copolymers are introduced into a PETP methods for the synthesis of block copolymers: reaction mixture of a two-phase nature, copolymers with a block structure are formed. The first method uses polymerization by the addition of monomers one after the other on the mechanism The effect of temperature and heating time and of \"living\" chains. heating rate on the properties of ceramic fibers is considered. The glassing temperature increases with The second method is based on the interaction of increasing heating time. Much of the work has been two initially derived oligomers with functional groups devoted to the study of the complex of physical and at the end. mechanical properties of liquid crystalline copolyesters based on p-oxybenzoic acid (p-OBK) and polyethylene The third path is the polycondensation of the second terephthalate (PETP). block at the expense of the group at the end of the initially obtained block of the first monomer. Up to 75% liquid-crystalline (LC) - pure PETP liquefaction and crystallization have been detected in The second and third methods allow the use of a mixtures containing the component. Copolies that retain large variety of chemical structures. less than 30% p-OBK are in the isotronic glassy phase, copolies with a much higher content of the second Thus, a large number of reactions can be used to component are in the liquid crystalline state and are obtain block copolymers by attaching loops (cycles) or characterized by greater dielectric constant than the binding to the macromolecule the blocks synthesized by glassy state. This difference is due to the presence of polycondensation methods due to their opening. different orientation distributions on the copolyesters relative to the electric field direction of the main chains Morphological studies have now been performed on in different structural states. infrared spectral data show block copolymers that retain two blocks A and B, which that the components of the mixture interact due to the re- differ in nature. For a three-block copolymer that retains esterification reaction in the liquid. An increase in pressure three different incompatible block (ABS) n, the slows down the reaction between its components, manifestation of relatively new morphological reducing the free volume and mobility in the mixture. structures can be expected, with very little information In the study, p - OBK / PETP and their mixtures with about such copolymers in the literature. isotactic polypropylene (PP), polymethyl methacrylate (PMMA), polysulfate, polyethylene - 2,6 - naphthalate Simple and complex aromatic polyesters, polysulfones (PEN), p - oxybenzoic acid and 6,2 - oxynaphthoic acid and polyarylene ketones have high physical-mechanical (ONA) copolyester Investigation of the properties of SK and dielectric properties as well as high thermal stability, based sopholofir is underway. The following properties which is a complex of properties of a number of valuable of mixtures with P - OBK / PETF SK - copolymer of PP properties. were expressed by measured-specific volume, coefficient of thermal expansion a (alpha) and compressibility Due to the importance of the problem of creating b (betta). High pressure has been found to cause sorting thermogenerated polymers with high flame - and heat in PP fluid. In the field of liquefaction and crystallization tolerance combined with good physical - mechanical temperatures of PP, an increase in the coefficient of properties for various fields of technology , to determine thermal expansion and compressibility for all components the relationships between composition and properties is of the mixture (100 - 25% PP) was found, with a slight important from a scientific and practical point of view. change in these parameters for the SK - copolyeper. An increase in the amount of SK-polymer in the mixture The synthesis of copolyesters and block- significantly reduces the coefficient of thermal copolyesters to improve the basic physical-mechanical expansion, both in its solid state and in the liquid state strength and processingability of polymers, in particular, of PP, which must be taken into account when processing was carried out through the formation stage of oligomers with functional groups that are finally reactive. As a result of the work, oligomers of different chemical structures - oligosulfon, oligocetone, oligosulfonetone, oligoformals were synthesized and on their basis new aromatic copolyesters and block copolyesters were obtained. The obtained ceramic- and block-copolyefirsulfone ketones and polyacrylates based on dichlorohydrides of 69

№ 5 (98) май, 2022 г. the mixture into a product. In a mixture with polysulfon, Piezoelectrics were obtained from p-OBK / PETP and the SK component is grouped in the form of concentric p-OBK / ONA-based SK-polymers. 6, 2 - The temperature cylinders of different radii. Under such conditions, range of the time stability and performance of piezoelec- it remains responsible for the viscosity properties of the trics from oxynaphthoic acid-based polymer is higher mixtures. than that of PETF-based polymer. Table 1 shows the brands of PETF and p OBK-based ceramic fibers pro- duced in the United States. Table 1. PETP and p OBK-based polyesters Company Country Trade name Eastman Kodak Cо United States Vectron LCC - 10108 LCC - 10109 It was found that the use of 30% p-OBK / PETP SK Under the harsh conditions of operation of polymers copolifier results in a 110% increase in the 30% solubility in the presence of the effect of open flame, oxygen, high modulus of PMAA strength, without compromising its temperatures, polymer materials are required to recyclability. maintain their shape and size under the influence of high fire resistance and high temperature heat fluxes. The structure and properties of various SK ceramic Extensive research is being conducted on the synthesis polyesters are being investigated in the works. For of aromatic polyesters with high fire resistance and example, copolymers based on p-oxybenzoic acid (p- modification of existing samples of this type of polymer, OBK), polyethylene terephthalate, hydroquinone and based on the requirements for polymer materials. terephthalic acid are being studied. The addition of a Currently, the most widely used methods of reducing mixture of hydroquinone and terephthalic acid flammability are: accelerates crystallization and increases the degree of crystallization of polyesters. • Laying fire protection coatings; • Add fillers; In the study of the flow curves of homogeneous and • Oriented synthesis of polymers; heterogeneous liquids of PETP and acitoxybenzoic acid- • Introduction of flame retardants; based copolifers, it was confirmed that there are two • Chemical modification. structural areas of copolifier liquids. At low temperatures, A common, technologically easy way to increase there are highly liquefied crystals in the nematic phase, the fire resistance of polymers is their chemical modifi- and at high temperatures, where a homogeneous nematic cation, which can be carried out directly in the process liquid is formed. SK - fluid flow curves are typical for of copolymerization with a synthetic reactive modifier, viscous plastic systems, however, the tendency to have for example: exchange of bisphenols, various acids, a flow limit increases with increasing molecular mass other oxybrids and reaction of the obtained polymer. by and decreasing temperature. Extruds formed from modification during mechanical chemical treatment homogeneous liquefaction have much higher values of with additives capable of or during the processing of the molecular orientation and strength than extrudates polymer liquid. formed from heterophasic liquefaction. The effect of The most optimal methods of modification of aro- highly liquefied crystallites on the orientation process of matic polyesters in order to obtain high-strength self-ex- the structure and the decrease in the strength of the tinguishing materials under the influence of aggressive exudates increases with increasing proportion of the environments are condensing them from halogen-retain- mesogent fragment in the chain. ing monomers, as well as combining aromatic polyesters with halogen-containing compounds and using halogen- Examination of the structure of p-OBK / PETP and containing sewing agents. m atestoxibenzoic acid-based SK-copolymers by IQ, Various compounds (aromatic and aliphatic) are YaMPN and X-ray diffraction methods at wide angles used as modifiers. They inhibit combustion processes showed that the degree of orientation in copolymers and can not only give polymers some new properties, increases when the amount of p-oxybenzoy units but also improve their physical properties. increases from 60 to 75%. Reference: 1. Темирова, Матлаб Ибодовна, and Элбек Улуғбекович Файзиев. \"ЧАРМНИ ОШЛАШДА МАҲАЛЛИЙ СУВДА ЭРУВЧАН ФАОЛ СИНТЕТИК ПОЛИМЕРЛАРНИ ҚЎЛЛАШ.\" International Journal of Advanced Technology and Natural Sciences 2.1 (2021): 33-38. 2. Rayimov, Zuhriddin Xayriddin O’G’Li. \"Ftal angidridning vinillanish jarayoni erituvchilari.\" Science and Education 2.12 (2021): 266-269. 3. Садирова, Саодат Насреддиновна. \"ИННОВАЦИОННЫЕ БИМОДАЛЬНЫЕ СМОЛЫ.\" Universum: технические науки 11-4 (92) (2021): 74-76. 70

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