~1H NMR Studies of the Molecular Structure of FYAc-b-(MA-co-MMA) Block Terpolymer in Atom Transfer Radical Copolymerizatin Reaction

摘要

Atom transfer radical copolymerization of methyl acrylate (MA) and methyl methacrylate (MMA) with PVAc-CCl_3 telomer as macroinitiator and CuCI/N,N,N',N',N"-pentamethyldiethylenetriamine (PMDETA) catalyst system in bulk at 80℃ was investigated. The molecular structure of the poly(vinyl acetate-b-MA-co-MMA) block terpolymers were characterized by ~1H NMR and FTIR spectroscopies and gel permeation chromatography (GPC). The composition and end chain functionality of MA units in terpolymer increased with mole fraction of MA in the feed. The chain configuration of terpolymer indicated that the syndiotacticity of MMA repeating unit in terpolymer increased from 31.9 to 52.5 with MMA mole fraction in the feed. The experimental and theoretical number average molecular weights of terpolymer were studied. The molecular weight distributions of the synthesized block terpolymers were narrowed from 1.77 in macroinitiator to about 1.27-1.44. The theoretical number average molecular weight of terpolymer increased with overall molar conversion and composition of MMA unit in terpolymer. The overall propagation rate constants in ATRP of MA and MMA were calculated and increased with mole fraction of MA in the feed.