کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5187240 1381124 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ring-opening polymerization of ɛ-caprolactone by poly(propyleneglycol) in the presence of a monomer activator
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Ring-opening polymerization of ɛ-caprolactone by poly(propyleneglycol) in the presence of a monomer activator
چکیده انگلیسی

The ring-opening polymerization of ɛ-caprolactone (CL) was induced by using polypropylene glycol (PPG) as an initiator in the presence of the monomer activator HCl·Et2O to synthesize triblock copolymers composed of PPG and poly(ɛ-caprolactone) (PCL). The degree of CL conversion and the molecular weight of PCL increased linearly with the polymerization time or with the feed ratio of CL to PPG in the presence of HCl·Et2O in CH2Cl2 at 25 °C. The PCLs obtained had molecular weights close to the theoretical values calculated from the CL:PPG molar ratios and exhibited monomodal GPC curves with narrow polydispersity indexes. The apparent rate constant (kapp) for the polymerization of CL activated by HCl·Et2O was greatly affected by the ratio of HCl·Et2O/PPG. The activation energy for the polymerization of CL in this system was estimated to be 49.8 kJ/mol K. We successfully prepared PPG and PCL triblock copolymers using this activated monomer mechanism.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 50, Issue 25, 27 November 2009, Pages 6019-6023
نویسندگان
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