Determination of chain transfer constant to dodecanethiol in styrene methyl methacrylate and butyl acrylate methyl methacrylate copolymerization and effect of chain length on composition and stereochemical configuration of copolymers

摘要

Free radical copolymerization of styrene/methyl methacrylate (S/MMA) and butyl acrylate/methyl methacrylate (BA/MMA) in the presence of n-dodecanthiol (DDT) has been studied at 60 degrees C in a 3 mol/L benzene solution using 2,2'-azobis(isobutyronitrile) (AIBN) as initiator. Overall chain transfer constant to DDT has been determined far both copolymerization systems, as a function of monomer feed composition using complete molecular weight distribution and the Mayo method. Overall transfer coefficients have values which are dependent on both monomer feed composition and individual comonomer transfer values. Composition, sequence distribution, and stereoregularity of copolymers obtained are, in our experimental conditions, independent of copolymer molecular weight. (C) 1998 John Wiley & Sons, Inc. [References: 41]