Oxyanion-initiated Polymerization Of Methacrylates

Oxyanion-initiated polymerization of methacrylates was investigated. A series of well-defined benzyloxy end-capped poly[2-(N,N-dimthylamino)ethyl methacrylate] (BzO-PDMAEMA) had been synthesized via oxyanion-initiated polymerization. Their micellization behavior in aqueous solution and lower critical solution temperature (LCST) were studied. The results showed that they had excellent surface activity, and the values of critical micelle concentration (CMC) and LCST changed with the increase of molecular weight of BzO-PDMAEMA and pH of solution. Therefore, they have potential applications as polymeric surfactant in emulsion polymerization of styrene. The latexes obtained possessed a regular size and narrow polydispersity. We also synthesized two amphiphilic block copolymers, i.e. BzO-PMMA-b-PDMAEMA and BzO-PDMAEMA -b-PMMA, with narrow molecular weight distribution. The different monomer-addition sequence yielded two block copolymers, which were synthesized by using potassium benzyl alcoholate as initiator via oxyanionic polymerization. Their structures were comformed by 1H NMR, FTIR, and their molecular weights and molecular weight distributions were analyzed by 1H NMR and GPC. Compared with two kinds of diblock copolymers, their compositions are identical under the same ratios of monomer to initiator. This new discovery expanded monomers available for oxyanionic polymerization, and obtained the evidence of the living/control polymerization for oxyanion-initiated reaction.