Ternary Copolymerization of Trimethylvinyloxysilane, Styrene, and Acrylic Esters Catalyzed by Organoaluminum Compounds

Abstract

ABSTRACT:The ternary copolymerization of trimethylvinyloxysilane, styrene, and methyl or phenyl acrylate was attempted in the presence of organoaluminum compounds at 0°C. All copolymers had a considerable amount of five-membered lactone structures in their backbone chains following the hydrolysis of the trimethylsiloxy group. These copolymers originally had a I : I composition between acrylate as an electron acceptor and the other two components as electron donors, and therefore could be recognized as copolymers of two alternating units, trimethylvinyland The conversion of lactonization was often beyond 86.5% (Flory's limit) being nearly 100%, especially in copolymers containing the phenyl acrylate component. Additional lactonization of the copolymers did not occur under the same conditions used in the work-up process. Hence, the realized conversion resulted from a statistical intramolecular reaction between trimethylsiloxy and alkoxycarbonyl groups. These terpolymers may thus be regarded as a model of the "specially-designed alternating copolymer" described in the preceding paper.KEY Recently, attention has been directed to the permeation and transport activities of particular ions of membranes of synthetic polymers containing lactone structures. 1 Such polymers can be synthesized either by polymerizing unsaturated lactone monomers or by reacting two neighboring substituents on a copolymer chain so as to form an ester bond. However, misaturated lactone monomers often show low polymerizabilities 2 and the substituents of a simple copolymer are not always arranged in favor of intramolecular lactonization. achieve 100% conversion. Inevitably, 13.5% of the substituents remain unreacted, as was experimentally observed in Hirooka's study. 4