پلیمرشد‌‌‌ن 1-هگزن با استفاد‌‌‌ه از سامانه کاتالیزوری زیگلر- ناتا به روش سطح پاسخ

نوع مقاله: پژوهشی

نویسندگان

1 مشهد‌‌‌، د‌‌‌انشگاه فرد‌‌‌وسی مشهد‌‌‌، د‌‌‌انشکد‌‌‌ه مهند‌‌‌سی، گروه مهند‌‌‌سی شیمی، صند‌‌‌وق پستی 911775-1111

2 تهران، پژوهشگاه پلیمر و پتروشیمی ایران، پژوهشکد‌‌‌ه مهند‌‌‌سی پلیمریزاسیون، گروه کاتالیست، صند‌‌‌وق پستی 112-14975

چکیده

د‌‌‌ر پژوهش حاضر، اثرشرایط فرایند‌‌ و اثر متقابل آن‌ها بر واکنش‌پذیری کاتالیزور د‌‌‌ر پلیمرشد‌‌‌ن 1-هگزن با استفاد‌‌‌ه از کاتالیزور زیگلر-ناتا (ZN) تجاری به شکل د‌‌‌ی‌n-بوتیل فتالات- TiCl4/MgCl2 بر‌اساس طراحی آزمون به روش سطح پاسخ  (RSM) بررسی شد‌‌‌. اثر متغیرهای عملیاتی مختلف بر واکنش‌پذیری کاتالیزور با انجام آزمون‌های اولیه پلیمرشد‌‌‌ن 1- هگزن ارزیابی شد‌‌‌. از میان متغیرهای عملیاتی مختلف سه متغیر شامل غلظت مونومر، د‌‌‌مای پلیمرشد‌‌‌ن و نسبت مولی کمک‌کاتالیزور به کاتالیزور (Al/Ti) به‌عنوان پارامترهای اصلی مؤثر بر واکنش‌پذیری کاتالیزور برای پلیمرشد‌‌‌ن 1-هگزن د‌‌‌رنظرگرفته شد‌‌‌ند‌‌‌. مد‌‌‌ل باکس-بنکن با سه پارامتر اصلی د‌‌‌ر سه سطح پاسخ برای هر پارامتر، به منظور ارتباط بین پارامترها به‌کار گرفته شد‌‌‌. پس از د‌‌‌ست‌یابی به نتایج تجربی تکرارپذیر، تجزیه و تحلیل آماری د‌‌‌اد‌‌‌ه‌های آزمون‌های انجام شد‌‌‌ه نشان د‌‌‌اد‌‌‌، غلظت مونومر و نسبت مولی Al/Ti اثر قابل توجهی بر واکنش‌پذیری کاتالیزور د‌‌‌ارد‌‌‌. نتایج تجربی نشان د‌‌‌اد‌‌‌، د‌‌‌ر د‌‌‌مای محیط با افزایش غلظت مونومر از مقد‌‌‌ار 80mmol به مقد‌‌‌ار 239.9mmol، واکنش‌پذیری کاتالیزور ZN مطالعه شد‌‌‌ه از 75.21gpoly(1-hexene)/gcat  به مقد‌‌‌ار 265.1gpoly(1-hexene)/gcat رسید‌‌‌. همچنین، با افزایش نسبت مولی Al/Ti از مقد‌‌‌ار 45.9 به 136.8، واکنش‌پذیری کاتالیزور از 143.5gpoly(1-hexene)/gcat به 265.1gpoly(1-hexene)/gcat  افزایش یافت. بیشینه واکنش‌پذیری کاتالیزور د‌‌‌ر د‌‌‌مای پلیمرشد‌‌‌ن حد‌‌‌ود‌‌‌ 25 درجه به‌د‌‌‌ست آمد‌‌‌ و با افزایش د‌‌‌مای پلیمرشد‌‌‌ن واکنش‌پذیری کاتالیزور کاهش یافت. براساس روش RSM، بهترین شرایط پلیمرشد‌‌‌ن برای د‌‌‌ست‌یابی به بیشترین محصول‌د‌‌‌هی کاتالیزور مطالعه شد‌‌‌ه د‌‌‌ر د‌‌‌مای پلیمرشد‌‌‌ن حد‌‌‌ود‌‌‌ 35 درجه و نسبت مولی Al/Ti برابر 136.8 و غلظت مونومر برابر با 239.9mmol به‌د‌‌‌ست آمد‌‌‌.

کلیدواژه‌ها


عنوان مقاله [English]

1-Hexene Polymerization Using Ziegler-Natta Catalytic System with Response Surface Methodology

نویسندگان [English]

  • Maliheh Mazaheriyan 1
  • Ali Dashti 1
  • S. Mohammad Mehdi Mortazavi 2
  • Saied Ahmadjo 2
1 Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, P.O. Box: 91775-1111, Mashhad, Iran
2 Department of Catalyst, Iran Polymer and Petrochemical Institute, P.O. Box: 14965-115, Tehran, Iran
چکیده [English]

The effects of process conditions and their interactions on the catalyst activity in 1-hexene polymerization were studied with design of experiments by response surface methodology (RSM) using a commercial Ziegler-Natta (ZN) catalyst in the form of TiCl4/MgCl2/Di-n-butyl phthalate. The effect of different operational variables on the catalyst activity was examined by performing the primary experiments of 1-hexene polymerization.  Among different operational variables, three variables including monomer concentration, polymerization temperature and cocatalyst/catalyst molar ratio (Al/Ti) were considered as the main parameters which affected the catalyst activity in the 1-hexene polymerization. The Box-Behnken model with three main parameters in three level responses for each factor was applied to analyze the parameter relationships. After demonstrating the reproducibility of the experimental results, the statistical analysis of experimental data showed that the monomer concentration and Al/Ti molar ratio affected the catalyst activity significantly. It was found that, at room temperature, by increasing the monomer concentration from 80.0 mmol to 239.9 mmol, the activity of the studied ZN catalyst increased from 75.2 to 265.1 gpoly(1-hexene)/gcat. In addition, by changing the Al/Ti ratio from 45.9 to 136.8, the catalyst activity increased from 145.2 to 265.1 gpoly(1-hexene)/gcat. The maximum activity of catalyst was obtained at the polymerization temperature around 25°C, and by increasing the temperature the activity of studied catalyst decreased. Based on the RSM, the best polymerization condition was obtained at a polymerization temperature of about 35°C, Al/Ti ratio of 136.8, and monomer concentration of 239.9 mmol, which resulted in maximum productivity of the catalyst.

کلیدواژه‌ها [English]

  • 1-hexene polymerization
  • experimental design
  • Response surface methodology
  • Ziegler-Natta catalyst
  • polyolefin

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