POLIMER CHIQINDILARINING TERMIK PARCHALANISH JARAYONINI KINETIK TAHLIL QILISH VA EKALOGIK AHAMIYATI

SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 10 POLIMER CHIQINDILARINING TERMIK PARCHALANISH JARAYONINI KINETIK TAHLIL QILISH VA EKALOGIK AHAMIYATI Ismoilov Mo‘minjon Yusupovich Farg‘ona davlat universiteti, k.f.d, professor [email protected] +99891 283 30 20 https://orcid.org/0000-0001-8212-4493 Qurbonaliyev Komronbek Azamat o‘g‘li Farg‘ona davlat universiteti, tayanch doktarant komronqurbonaliy[email protected]om +99890 530 08 90 https://orcid.org/0009-0004-5438-3956 Anotatsiya Xalqaro miqyosda polimer materiallar yillik ishlab chiqarilishi 400 million tonnani tashkil etib, bu moddalarning turli sohalardagi keng qamrovli foydalanishini namoyon etadi. Ammo bu rivojlanish bilan birga muhim muammolar paydo bo‘ldi, jumladan, yuksak darajadagi chiqindilar ombori va ularning atrof-muhitga ta’siri. Polimer zavodlari, ayniqsa gazdan polimer olish zavodlari, shu chiqindilarning eng katta manbalaridan biri hisoblanadi. Bu chiqindilar asosan “tar” mahsulotlar, ya’ni polimerlashtirish jarayonida reaksiyadan holi qolgan, bajaruvchi komponentlardan tashkil topgan kompleks qattiq moddalardir. Tar mahsulotlar asosan fenollar (45%) va politsiklik aromatik gidrokarbonlar (PAH, 31%) dan iborat bo‘lib, ular oson parchalanmaydigan va xavfligicha to'yingan birikmalar tarkibiga ega. Shunday qilib, tar mahsulotlaridan muhofaza qilish ekologik va iqtisodiy jihatdan muhim muammo hisoblanadi [8:1169]. SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 11 Kalit so‘zlar: polimer chiqindisi, termik parchalanish, kinetik tahlil, Arrenius tenglamasi, faollanish energiyasi, “Tar” mahsuloti, politsiklik aromatik gidrokarbonlar (PAH), TG-DTG, reaksiya mexanizmi. Abstract Globally, the annual production of polymer materials reaches 400 million tons, demonstrating the extensive use of these substances across various sectors. However, this development is accompanied by significant problems, including large-scale waste accumulation and its impact on the environment. Polymer plants, particularly those producing polymers from gas, are one of the largest sources of this waste. This waste mainly consists of "tar" products—complex solid substances formed by unreacted components remaining from the polymerization process. Tar products are predominantly composed of phenols (45%) and polycyclic aromatic hydrocarbons (PAH, 31%), which are difficult to degrade and contain hazardous saturated compounds. Thus, the disposal and valorization of tar products is a crucial ecological and economic problem [8:1169]. Keywords: Polymer waste, thermal degradation (or thermal decomposition), kinetic analysis, Arrhenius equation, activation energy, “Tar” product, polycyclic aromatic hydrocarbons (PAH), TG-DTG, reaction mechanism. Kirish. Kinetik tahlil — bu reaksiya tezligi va uni barqarorligi aniqlaydigan parametrlarni o‘rganishdir [5:567]. Bu ma’lumotlar piroliz reaktorning optimallashtirilgan loyihasini ishlab chiqish uchun zarur asos hisoblanadi [1:1128]. Reaksiyaning necha minutda, qanday bosimda va qanday haroratda amalga oshirilishi kerakligini aniqlovchi matematik model yaratish imkonini beradi. Ushbu maqola, gazdan polimer zavodlari chiqindisi — tar mahsulotlarning termik parchalanish jarayonini kinetik tahlili uchun ma’lumotlar bazasini shakllantirishga bag‘ishlangan bo‘lib, uning asosiy maqsadi bunday murakkab aralashmaning parchalanish mexanizmini tushunish, parchalanish tezligini va energiya talabini baholash hamda keyingi ilmiy tadqiqotlar uchun asos yaratishdir. Eksperimental metodika: TG-DTG tahlil natijalari va keltirilgan SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 12 ma’lumotlar. O‘zbekiston Fanlar akademiyasi Polimer kimyo va fizika instituti ilmiy ishchilari Normurodov N. F. va Ashurov N. N. LLDPE-g-MA/gelatin aralashmasining morfologik va issiqlik xususiyatlarini o‘rganishgan. Ularning tahliliga ko‘ra, gelatin miqdorining ortishi aralashmaning parchalanishiga sezilarli ta’sir qiladi. Aralashma tarkibidagi gelatin miqdori 30-60% gacha bo'lganda, parchalanish boshlanish harorati (Ti) 242°C dan (to‘liq polietilen uchun) 190°C gacha pasaygan. TGA tahlili 10°C/min tezlikda, havo muhitida o‘tkazilgani sababli, bu ma’lumotlar peptid bog‘larining parchalanishiga bog‘liq bo‘lgan 275–400°C oralig‘idagi parchalanish bosqichini anglatadi. 1-jadval. Parchalanish haroratini polimer tarkibiga bog‘liqligi. Namuna tarkibi O‘rtacha parchalanish harorati (°C) Boshqa parchalanish xususiyatlari Gelatin (to‘liq) 97 Boshlanish parchalanish harorati LLDPE-g-MA (to‘liq) 242 Boshlanish parchalanish harorati LLDPE-g-MA/ Gel 50/50 190 Boshlanish parchalanish harorati, 10-40°C pasaydi HDPE 492–525 Yakuniy parchalanish oralig‘i [2:435] HDPE ~459 DTG egri chiziqdagi maksimal parchalanish harorati (Tpeak) [6:1960] PP/PET Aralashma Yuqori Erish harorati va issiqlikka chidamlilik PET miqdoriga qarab oshadi [7:3] EPDM rezina 75-150 °C oralig'ida stress relaxatsiyasiga Faollanish energiyasi ~91-92 kJ/mol SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 13 bog‘liq Bio-tar 183–252 Tez parchalanish harorati oralig‘i Ushbu jadvaldan ko‘rinadiki, parchalanish harorati polimer tarkibiga bog‘liq bo‘lib, turlicha komponentlar bir-birini ta’sir qiladi. Masalan, gelatin polietilenga nisbatan past parchalanish haroratiga ega bo‘lgani uchun undan tashkil topgan aralashmadagi parchalanish boshlanishi ham past haroratlarda sodir bo‘ladi. Kinetik modelga asoslangan parchalanish jarayoning matematik tasviri. Polimerlarning termik parchalanish jarayoni, asosan, molekulaning asosiy valent bog‘larining uzilib, ikki yoki undan ortiq mikroskopik radikal (erkin birikmalar) hosil bo‘lishi natijasida sodir bo‘ladi. Bu jarayon zanjir reaktsiyasi deb ataladi, chunki paydo bo‘lgan radikallar boshqa bog‘lar ustida reaksiyaga kirib, zanjirni davom ettiradi. Kinetik tahlil bu jarayonni matematik modellar yordamida ifodalashga va uning dinamikasini tushunishga yordam beradi. Asosiy kinetik tenglama — bu Arrenius tenglamasi bo‘lib, bu reaksiya tezlik doimiysi (k) va temperaturaga (T) bog‘liq bo‘lishini tavsiflab, parchalanish jarayonining tezligini matematik ravishda ifodalaydi. Tenglama quyidagi shaklda beriladi: k(T) = A * exp(-Eₐ / (R*T)) Bu yerda: k(T) — temperaturaga bog‘liq reaksiya tezlik doimiysi. A — Arrenius oldindan eksponensial omil (yoki chastotali omil), bu reaksiyaga kirishuvchi molekulalarning cho‘qqisidan o‘tish chastoligi bilan bog‘liq. Eₐ (Ea) — faollanish energiyasi, bu reaksiyaga kirishish uchun kerak bo‘lgan minimal energiya miqdori. R — universall gaz doimiysi. T — mutlaq harorat Kelvin (K). Parchalanish mexanizimi va termik xatti-harakatlarga ta’sir qiluvchi omillar. Polimerlarning termik parchalanish jarayoni, faqatgina harorat ta'sirida sodir bo'ladigan oddiy jarayon emas, balki molekulyar tuzilish, kimyoviy tarkib va muhit SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 14 sharoitlari bilan siyosat qilinadigan murakkab fizikaviy-kimyoviy jarayon hisoblanadi [4:136070]. Bu jarayon uch bosqichda amalga oshiriladi: initsializatsiya (erkin radikallarning paydo bo‘lishi), tarqatish (radikallarning zanjirlanishi) va tugatish (radikallarning rekombinatsiyasi). Bu bosqichlarning o‘rtasidagi muvozanat parchalanish mexanizmini belgilaydi. Parchalanish mexanizmi polimer tarkibiga bog‘liq. Masalan, polietilen (PE) va polipropilen (PP) kabi poliolefinlar asosiy zanjirning ichki bog‘larida (beta-o‘q bog‘larida) oson uziladi. Bu jarayon yuqori harorat va UB nurlanish ta’sirida tezlashadi. Xulosa va takliflar. Bu tadqiqot, gazdan polimer zavodlari chiqindisining termik parchalanish jarayonini kinetik tahlili uchun katta ahamiyatga ega bo‘lgan ma’lumotlar beradi. Keltirilgan ma’lumotlar , ayniqsa, LLDPE-g-MA/gelatin va PP/PET aralashmalari uchun uch bosqichli parchalanishni ko‘rsatdi [7:5]. Bu esa, murakkab tarkibli namunalar (masalan, tar mahsulot) ham parchalanish jarayonini bir necha parallel yoki ketma-ket reaksiyalar yig‘indisi sifatida tushunish kerakligini ko‘rsatadi. Bu murakkablikni tushunish, kinetik tahlil uchun aniq model tanlash va parchalanish jarayonini boshqaruvi uchun optimallashtirilgan algoritmlar ishlab chiqish uchun zarur asosdir. Ushbu ma’lumotlar keyingi ilmiy tadqiqotlar, na’muna tarkibiga qarab moslashuvchan kinetik modellar yaratish va termik parchalanish jarayonini boshqaruvi uchun optimallashtirilgan texnologik parametrlarini aniqlashga yordam beradi. Foydalanilgan adabiyotlar 1. Kan, T., Strezov, V., & Evans, T. J. (2016). Lignocellulosic biomass pyrolysis: A review of product properties and effects of pyrolysis parameters. Renewable and Sustainable Energy Reviews, 57, 1126–1140. SCIENCE AND PEDAGOGY IN THE MODERN WORLD: PROBLEMS AND SOLUTIONS Vol. 3. Issue 9. 15 2. Yoshioka, T., Gomi, A., Okuwaki, A., & Walter, P. E. (2004). Thermal degradation of polyethylene and polypropylene mixtures. Polymer degradation and stability, 83(3), 433–438. 3. Czernik, S., & Bridgewater, A. V. (2004). Overview of applications of biomass fast pyrolysis oil. Energy & fuels, 18(2), 590–598. 4. Singh, R. K., Ruj, B., Sadhukhan, A. K., & Gupta, P. (2022). Biochars and activated carbons as adsorbents of inorganic and organic compounds from multicomponent systems–A review. Chemical Engineering Journal, 444, 136067. 5. D’Allura, A. M., Pezzino, G., & Dattilo, S. (2018). Thermal degradation and kinetic analysis of polymer blends and composites. Polymers, 10(5), 565. 6. Williams, P. T. (2010). Pyrolysis of waste plastics and tyres: an overview. Waste Management, 30(11), 1957–1964. 7. Kyaw, A. K., Muto, A., Oshima, Y., & Nakagawa, T. (2017). Thermal degradation of poly(ethylene terephthalate) (PET) and polypropylene (PP) mixed plastic waste. 8. Wong, S. L., Ngadi, N., Abdullah, T. A. T., & Inuwa, I. M. (2015). Current state and future prospects of plastic waste as source of fuel: A review. Renewable and Sustainable Energy Reviews, 50, 1167–1180. 9. Wang, Z., Zhang, S., Li, Y., Zhao, Y., & Fu, J. (2020). Kinetic analysis of municipal solid waste pyrolysis using TGA coupled with Kissinger– Akahira–Sunose and Flynn–Wall–Ozawa methods. Waste Management, 102, 333342.