Accession Number : ADA309786

Title :   Kinetic Studies of Atom Transfer Radical Polymerization of Methyl Acrylate.

Descriptive Note : Technical rept.,

Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF CHEMISTRY

Personal Author(s) : Paik, H. ; Matyjaszewski, K.

PDF Url : ADA309786

Report Date : 12 JUN 1996

Pagination or Media Count : 5

Abstract : Kinetic aspects of Atom Transfer Radical Polymerization of methyl acrylate MA were studied. The results showed the characteristic features of living polymerization up to Mn (80,000, e.g. constant concentration of propagating species, a linear relation between conversion and molecular weight and narrow polydispersities (Mw/Mn (1.2). As an initiation system, 2- bromomethyl propionate and CuBr complexed by 4,4'-Di-tert-butyl-2,2'-bipyridine DThipy or 4,4'-di-(5-nonyl)-2,2'-bipyridine DNbipy were employed. Kinetic studies showed that the propagation rate is first order in relation to the monomer and initiator. For the homogeneous catalyst system (copper(I)/dNbipy), the propagation rate is first order with respect to the initial concentration of catalyst and inverse first order with respect to the initial concentration of Cu(II)Br2. The propagation rate in non-homogeneous system (copper(I)/dTbipy) less depends on the on the initial concentration of catalyst and Cu(II)Br2. These results can be explained by the reversible formation of growing polyacrylate radicals by the reaction of dormant bromo-terminated chains with copper halide.

Descriptors :   *POLYMERIZATION, *METHACRYLATES, REACTION KINETICS, MOLECULAR WEIGHT, COPPER COMPOUNDS, HALIDES, CATALYSTS, CHEMICAL RADICALS.

Subject Categories : Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE