Controlled Synthesis of Various Poly(Alkyl Methacrylates) by Anionic Techniques

Abstract

Homopolymer synthesis investigations have further defined the requirements for the controlled anionic synthesis of various poly(alkyl methacrylates). Small variations in polymerization conditions have a profound influence on the nature of the propagating lithium enolate. However, the effects depend largely upon the size of the ester alkyl group involved. The delicate relationship among such variables as ester alkyl group size, polymerization temperature and polymerization solvent have been explored and will be discussed. Drastically different enolate stabilities have been observed for the bulkier branched alkyl methacrylates compared to those based upon linear ester alkyl groups. This has been primarily attributed to the significantly modified steric and electronic environment of the ester carbonyl. Thus, the constraints of classical alkyl methacrylate polymerizations, i.e., low temperatures and polar solvents, may be overcome by the judicious choice of the ester alkyl group. Extensive thermal, microstructural, and mechanical characterization reveal that a wide range of polymer physical properties can be achieved by the careful alteration of several variables.