Atom-Transfer Radical Polymerization of a Reactive Monomer: 3-(Trimethoxysilyl)propyl Methacrylate

Abstract

Atom-transfer radical polymerizations (ATRPs) of a reactive monomer, 3-(trimethoxysilyl)propyl methacrylate (TMSPMA), mediated by CuBr/N,N,N‘,N‘ ‘,N‘ ‘-pentamethyldiethylenetriamine (PMDETA) in anisole have been studied using ethyl 2-bromoisobutyrate (2-EBiB) and poly(ethylene oxide) methyl ether 2-bromoisobutyrate (PEO-Br) as initiators. In general, the polymerizations of TMSPMA exhibited first-order kinetics, and molecular weights increased linearly with monomer conversion. Molecular weight distributions remained low throughout the polymerizations (Mw/Mn = 1.20−1.40). The overall rate of polymerization with PEO-Br as the initiator was enhanced compared to that with 2-EBiB as the initiator. A series of reactive diblock copolymers, poly(ethylene oxide)-b-poly[3-(trimethoxysilyl)propyl methacrylate] (PEO-b-PTMSPMA), were thus synthesized. By random copolymerization with methyl methacrylate (MMA), PEO-b-P(TMSPMA-r-MMA) copolymer was prepared at the same time. Organic/inorganic hybrid nanospheres were produced by the self-assembly of PEO-b-P(TMSPMA-r-MMA) in a selective solvent and further gelation of the trimethoxylsilyl groups within each individual sphere. Preparation of organic/inorganic nanocomposites was also explored preliminarily on the basis of the sol−gel process of PEO-b-PTMSPMA diblock copolymers and the tetraethyl orthosilicate.