کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5182001 1380977 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
RAFT ab initio emulsion copolymerization of γ-methyl-α-methylene-γ-butyrolactone and styrene
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
RAFT ab initio emulsion copolymerization of γ-methyl-α-methylene-γ-butyrolactone and styrene
چکیده انگلیسی

RAFT ab initio emulsion copolymerization of γ-methyl-α-methylene-γ-butyrolactone (MeMBL) and styrene with various monomer ratios was investigated with PAA20-PS5 trithiocarbonate being mediator and surfactant at 70 °C. The polymerization was fully controlled as evidenced by stable latexes, well predicted molecular weights and low PDIs about 1.2 when [MeMBL]:[St] ≤ 1:2. However, in the case of [MeMBL]:[St] = 1:1, the molecular weight became out of control due to gel effect of RAFT reactions. The relatively water-soluble MeMBL was found to dramatically influence the polymerization kinetics and copolymer properties, as evidenced by (1) No inhibition period was observed; (2) The copolymer compositions in the early stage of polymerization were much higher than those predicted by the Mayo-Lewis equation in the case of [MeMBL]:[St] = 1:2, leading to the formation of linear gradient copolymer. (3) Tgs of the copolymers from emulsion copolymerization were higher than those from bulk copolymerization. It was concluded that we could synthesize the gradient copolymer with preset molecular weight and low PDI in RAFT emulsion polymerization, Tg of which should be much higher than 100 °C.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 54, Issue 7, 22 March 2013, Pages 1779-1785
نویسندگان
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