Atom transfer radical polymerization of protected methacrylic acids

Abstract

The atom transfer radical polymerization (ATRP) of methacrylic acid (MA) protected by trimethylsilyl, tetrahydropyranyl, tert-butyl or benzyl groups was carried out. Polymerization of trimethylsilyl methacrylate led to no polymer formation likely due to side reactions, such as hydrolysis and SN2 nucleophilic attack of terminal halogen. The ATRP of tetrahydropyranyl methacrylate yielded polymers with limited conversion. Evidence showed that cleavage of the tetrahydropyranyl protecting group occurred during the polymerization. The ATRP of tert-butyl or benzyl methacrylate under appropriate conditions afforded well-defined polymers. Subsequent hydrolysis of these polymers can yield poly(MA) with predictable molecular weight and low polydispersities.