کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5188046 | 1381144 | 2008 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Polyisobutylene-based miktoarm star polymers via a combination of carbocationic and atom transfer radical polymerizations
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
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چکیده انگلیسی
Poly(isobutylene-b-styrene) (PIB-PS) copolymers and polyisobutylene (PIB) homopolymers were synthesized via quasiliving carbocationic polymerization from the initiator 3,3,5-trimethyl-5-chlorohexyl acetate, which contains a protected hydroxyl group. The PIB block was created at â70 °C in a methylcyclohexane/methyl chloride (60:40) cosolvent system, using TiCl4 as co-initiator, followed optionally by sequential addition of styrene. Using a strong base, the acetate head group of the resulting block copolymer was cleaved to yield a hydroxyl group, which was subsequently esterified with the branching agent 2,2-bis((2-bromo-2-methyl)propionatomethyl)propionyl chloride (BPPC) to create dual initiating sites for atom transfer radical polymerization (ATRP). ATRP of tert-butyl acrylate was carried out using a Cu(I)Br/1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA) catalyst system. In some cases, the ester side chains of the poly(tert-butyl acrylate) (PtBA) blocks were cleaved to create poly(acrylic acid) (PAA) blocks. The final miktoarm star polymers had compositions that were very close to theoretical.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 49, Issue 5, 3 March 2008, Pages 1154-1163
Journal: Polymer - Volume 49, Issue 5, 3 March 2008, Pages 1154-1163
نویسندگان
L. Krystin Breland, Robson F. Storey,