Synthesis of poly(tert‐butyl methacrylate)‐graft‐poly(dimethylsiloxane) graft copolymers via reversible addition‐fragmentation chain transfer polymerization

Abstract

Well‐defined poly(tert‐butyl methacrylate)‐graft‐poly (dimethylsiloxane) (PtBuMA‐g‐PDMS) graft copolymers were synthesized via reversible addition‐fragmentation chain transfer (RAFT) copolymerization of methacryloyl‐terminated poly (dimethylsiloxane) (PDMS‐MA) with tert‐butyl methacrylate (tBuMA) in ethyl acetate, using 2,2′‐azobis(isobutyronitrile) (AIBN) as the initiator and 2‐cyanoprop‐2‐yl dithiobenzoate as the RAFT agent. The RAFT statistical copolymerization of PDMS‐MA with tBuMA is shown to be azeotropic and the obtained PtBuMA‐g‐PDMS graft copolymers have homogeneously distributed branches because of the similar reactivity of monomers (rtBuMA ≈ rPDMS‐MA ≈ 1). By the RAFT block copolymerization of PDMS‐MA with tBuMA, moreover, narrow molecular weight distribution (Mw/Mn < 1.3) PtBuMA‐g‐PDMS graft copolymers with gradient or blocky branch spacing were synthesized. The graft copolymers exhibit the glass transitions corresponding to the PDMS and PtBuMA phase, respectively. However, the arrangement of monomer units in copolymer chains and the length of PtBuMA moieties have important effects on the thermal behavior of PtBuMA‐g‐PDMS graft copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Silicone containing copolymers: Synthesis, properties and applications

“…Silicone-acrylic block, segmented and graft copolymers and interpenetrating networks have also been extensively investigated . In addition to basic studies on the composition dependent structure-morphology-surface behavior (270,274,276,281,282,284,285,290), these materials were also investigated as protective coatings (271,279,287), adhesives (273,277,283), membranes (286,288,289)and biomaterials (268,272).…”

Synthesis of bottlebrush copolymers based on poly(dimethylsiloxane) for surface active additives

“…[30][31] There are limited reports on branched PDMS polymers. [30][31][32][33][34][35][36] RAFT polymerization of methacrylate-terminated PDMS has produced bottlebrush PDMS with side-chain M n of 1 or 4.3 kg/mol and backbone degree of polymerizations (DP) up to 70 for the shorter side-chains. [32][33] Masuda et al 34 reported branched PDMS material with M w up to 349 kg/mol but with broad molecular weight dispersity (Đ = 1.7 -3.2).…”

Poly(N‐vinylimidazole)‐l‐poly(tetrahydrofuran) amphiphilic conetworks and gels. II. Unexpected dependence of the reactivity of poly(tetrahydrofuran) macromonomer cross‐linker on molecular weight in copolymerization with N‐vinylimidazole

“…Monofunctional macromonomers with one terminal polymerizable group are frequently used to prepare graft copolymers via copolymerization with low molecular weight monomers (see e.g., refs 28–44. and references therein).…”