Eur. Phys. J. B 12, 397-404 (1999)
https://doi.org/10.1007/s100510051021

Influence of polydispersity on the phase behavior of statistical multiblock copolymers with Schultz-Zimm block molecular weight distributions

¹ Department of Polymer Chemistry and Materials Science Centre, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
² Department for Physical, Analytical and Computational Chemistry, DSM Research, P.O. Box 18, 6160 MD, Geleen, The Netherlands

Corresponding author: ^a angerman@chem.rug.nl

Received: 2 July 1998
Published online: 15 December 1999

Abstract

In this paper we investigate in a systematic way the influence of polydispersity in the block lengths on the phase behavior of AB-multiblock copolymer melts. As model system we take a polydisperse multiblock copolymer for which both the A-blocks and the B-blocks satisfy a Schultz-Zimm distribution. In the limit of low polydispersity the expressions for the vertex functions are clarified by using simple physical arguments. For various values of the polydispersity the phase diagram is presented, which shows that the region of stability of the bcc phase increases considerably with increasing polydispersity. The strong dependence of the periodicity of the microstructure on the polydispersity and on the interaction strength is presented.