Comb copolymers of polystyrene-poly(tert-butyl (meth)acrylate) prepared by combination of nitroxide mediated polymerization and photoinduced iniferter technique
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- 作者：Daniel Gromadzki ; Rič ; ardas Makuš ; ka ; Miloš ; Netopilí ; k ; Petr Holler ; Jan Lokaj ; Miroslav Janata ; Petr Š ; tě ; pá ; nek
- 关键词：Controlled radical polymerization ; TEMPO ; Macro-iniferter ; Polystyrene-graft-poly(tert-butyl methacrylate) ; Amphiphilic graft copolymer
- 刊名：European Polymer Journal
- 出版年：2008
- 出版时间：January 2008
- 年：2008
- 卷：44
- 期：1
- 页码：59-71
- 全文大小：334 K
文摘
Comb copolymers consisting of polystyrene backbone and poly(tert-butyl (meth)acrylate) side chains were synthesized by combination of nitroxide (TEMPO)-mediated polymerization (NMP) and photoinduced grafting from macro-iniferters. First, poly(chloromethylstyrene), PCMS, with the degree of polymerization ![]()
and two random poly(styrene-co-chloromethylstyrene) copolymers, P(S-co-CMS), with similar ![]()
but different content (8 and 14 mol % ) of CMS units, were synthesized by NMP. In the second step the CMS units both in the homopolymer and the copolymers were converted to N,N-diethyldithiocarbamyl groups (DC) yielding photosensitive multifunctional macro-iniferters. Finally, tert-butyl methacrylate tBuMA was grafted from the synthesized polymer backbones by iniferter technique under UV-irradiation yielding copolymers polystyrene-graft-poly(tert-butyl methacrylate) PS-g-P(tBuMA). Grafting initiated by the macro-iniferters containing ![]()
6–11 DC initiating sites per macromolecule proceeded by pseudo-living polymerization mechanism, i.e., the number-average molecular weight increased with conversion and the SEC traces were unimodal. In contrast, photo-polymerization initiated by highly functionalized polystyrene backbone was poorly controlled. Hydrolysis of loosely grafted copolymers PS-g-P(tBuMA) afforded amphiphilic copolymers polystyrene-graft-poly(methacrylic acid). Molecular parameters of the synthesized graft copolymers in dilute THF solutions were determined by scattering (DLS, SLS, SAXS) and viscometric measurements.