Diffusion and random chain scission

Abstract

Chain scission has been discussed as a process involving medium cages and diffusion of polymer fragments out of such cages. Two types of processes can be distinguished: completion of potential chain scission by segmental diffusion of chain ends and translational diffusion, respectively. The first will be operative for chain scission in solution with flexible polymer chains or for bulk scission. The second can be significant for stiff chains in solution. In both cases chain scission rate constants should be proportional to the reciprocal local medium viscosity. Segmental diffusion should show a dependence on reciprocal chain length for relatively short chains whereas translational diffusion should always be a strong function of reciprocal chain length. Data found in the literature concerning chain scission has been discussed in the light of such cage processes. © 1973, The Society of Polymer Science, Japan. All rights reserved.