کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5184334 1381045 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of prepolymer crystallinity on solid-state polymerization of poly(bisphenol A carbonate)
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
The effect of prepolymer crystallinity on solid-state polymerization of poly(bisphenol A carbonate)
چکیده انگلیسی

The effect of prepolymer crystallinity on the solid-state polymerization (SSP) of poly(bisphenol A carbonate) was examined using nitrogen as a sweep fluid. A low-molecular-weight prepolymer was synthesized by melt transesterification and prepolymers with different crystallinities (11.7%, 23.3%, 33.7%) were prepared with supercritical carbon dioxide treatment. SSP of the three prepolymers was then carried out at reaction temperatures in the range of 150-190 °C, with a prepolymer particle size of 75 μm and a N2 flow rate of 1600 ml/min. The glass-transition temperature (Tg), absolute weight-average molecular weight (Mn), and percent crystallinity were measured at various times during each SSP. At each reaction temperature, SSP of the lower crystallinity prepolymer (11.7%) always resulted in higher-molecular-weight polymers, compared with the polymers synthesized using the higher crystallinity prepolymer (23.3% and 33.7%). The crystallinity of the polymers synthesized from the high crystallinity prepolymer was significantly higher than for those synthesized from the low crystallinity prepolymer. Higher crystallinity of the prepolymer and the synthesized polymers may lower the reaction rate by reducing chain-end mobility or/and by inhibiting byproduct diffusion.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 51, Issue 12, 28 May 2010, Pages 2520-2526
نویسندگان
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