The relationship among changes in microstructure, active sites behavior and properties in the propylene polymerization with a 4th generation Ziegler-Natta catalyst
Publish place: Polyolefins Journal، Vol: 6، Issue: 2
Publish Year: 1398
نوع سند: مقاله ژورنالی
زبان: English
View: 482
This Paper With 12 Page And PDF Format Ready To Download
- Certificate
- من نویسنده این مقاله هستم
استخراج به نرم افزارهای پژوهشی:
شناسه ملی سند علمی:
JR_POJ-6-2_004
تاریخ نمایه سازی: 5 مرداد 1398
Abstract:
Three polypropylene samples (1-3) were synthesized with a 4th generation Ziegler-Natta catalyst in the presence of cyclohexyldimethoxymethylsilane (donor c), dicyclopenthyldimethoxysilane (donor d) and diisopropyldimethoxysilane (donor p), respectively, as external electron donors. The physical properties of the synthesized polypropylenes were determined. For samples 1 to 3, Successive self-nucleation and annealing (SSA) and Fourier transform infrared spectroscopy (FT-IR) analyses indicated that the relative content of the fraction with high isotacticity and regularity in conformational structure decreased in contrast with the fraction of low isotacticity and low uniformity in stereo-defect distribution from sample 1 to 3. The results demonstrated that the longer the isotactic sequence length and the less uniform the stereo-defect distribution, the greater the conformational order. Deconvolution of the molecular weight distribution curves indicated that the stability of the active centers increased from samples 1 to 3, but the participation of stereo-specefic active centers in the polymerization decreased. DMA tests showed that samples 3 and 1 had the highest damping ability and storage modulus, respectively.
Keywords:
Authors
Shokoufeh Hakim
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box: ۱۴۹۶۵/۱۱۵, Tehran, Iran
Mehdi Nekoomanesh
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box: ۱۴۹۶۵/۱۱۵, Tehran, Iran
Ali Shahrokhinia
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box: ۱۴۹۶۵/۱۱۵, Tehran, Iran
مراجع و منابع این Paper:
لیست زیر مراجع و منابع استفاده شده در این Paper را نمایش می دهد. این مراجع به صورت کاملا ماشینی و بر اساس هوش مصنوعی استخراج شده اند و لذا ممکن است دارای اشکالاتی باشند که به مرور زمان دقت استخراج این محتوا افزایش می یابد. مراجعی که مقالات مربوط به آنها در سیویلیکا نمایه شده و پیدا شده اند، به خود Paper لینک شده اند :