Remote Unit Effects in the Copolymerization of Unconjugated Monomers

The kinetics of the radical copolymerization of the three binary systems vinyl chloride (C)-vinyl acetate (Ac), vinylidene chloride (V)-vinyl acetate, and vinyl chloride-vinylidene chloride have been investigated in the whole range of monomer feed composition using the chromatographic method. Penultimate or antepenultimate effects have been observed in all cases. The better values of the corresponding reactivity ratios are: For C-Ac copolymers, rAc = 0.29, rCCC = 1.67, rAcCC. = 4.60, and rAcC = 2.05. For V-Ac copolymers, rAc = 0.07, rVVV = 5.30, rAcVV = 11.5, rAcAcV = 8.0, and rVAcV = 6.0. For C-V copolymers, rVAcV = 0.22, rVV = 2.94, and rCV = 4.31. An internal transfer mechanism is suggested for the antepenultimate effect in the vinyl acetate copolymers.