Potential bootstrap effect and phase separation of reaction solutions

The phase separation in monomer-copolymer solutions was studied for styrene -acrylonitrile, styrene-butyl methacrylate and styrene-methyl methacrylate systems in order to find conditions to stimulate a bootstrap effect in radi cal copolymerization. There was phase separation at T-sep < T-cop and a boo tstrap effect for the styrene-acrylonitrile and styrene-butyl methacrylate system, but no effects for the styrene-methyl methacrylate system. Both the data on the phase separation and the excess free energy of the monomer mix ing (Delta G(ex)) are needed to explain the dependence of the bootstrap eff ect on the temperature of the styrene-butyl methacrylate copolymerization. Temperature had a large influence on the copolymer inhomogeneity in the cop olymerization of styrene with butyl methacrylate in this study. (C) 1999 El sevier Science Ltd. All rights reserved.