Synthesis of PMMA-PTHF-PMMA and PMMA-PTHF-PST linear and star block copolymers
B Hazer, H Macit
article (Uluslararası, Hakemli) | Yazar(lar): B Hazer, H Macit | Yıl: 2004 | Dergi/Kurum: JOURNAL OF APPLIED POLYMER SCIENCE | İndeks: WOS.SCI | DOI: 10.1002/app.20455 | Anahtar Kelimeler: star polymers, cationic polymerization, polystyrene, polyethers, redox polymers — Özet: Combination of cationic, redox free radical
Combination of cationic, redox free radical, and thermal free radical polymerizations was performed to obtain linear and star polytetramethylene oxide (poly-THF)-polymethyl methacrylate (PMMA)/polystyrene (PSt) multiblock copolymers. Cationic polymerization of THF was initiated by the mixture of AgSbF(6) and bis(4,4' bromomethyl benzoyl) peroxide (BBP) or bis (3,5,3',5' dibromomethyl benzoyl) peroxide (BDBP) at 20degreesC to obtain linear and star poly-THF initiators with M(w) varying from 7,500 to 59,000 Da. Poly-THF samples with hydroxyl ends were used in the methyl methacrylate (MMA) polymerization in the presence of Ce(IV) salt at 40degreesC to obtain poly(THF-b-MMA) block copolymers containing the peroxide group in the middle. Poly(MMA-b-THF) linear and star block copolymers having the peroxide group in the chain were used in the polymerization of methyl methacrylate (MMA) and styrene (St) at 80degreesC to obtain PMMA-b-PTHF-b-PMMA and PMMA-b-PTHF-b-PSt linear and star multiblock copolymers. Polymers obtained were characterizated by GPC, FT-IR, DSC, TGA, (1)H-NMR, and (13)C-NMR techniques and the fractional precipitation method. (C) 2004 Wiley Periodicals, Inc.