Effects of polydispersity on the phase coexistence diagrams in multiblock copolymers with Laser block length distribution

TL;DR

This study investigates how polydispersity, modeled by Laser distribution parameters, affects phase diagrams and stability in multiblock copolymer melts using mean-field theory, revealing that increased polydispersity destabilizes the system.

Contribution

It introduces a detailed analysis of Laser distribution effects on phase behavior in multiblock copolymers, including higher order correlations and phase stability.

Findings

Increased polydispersity shifts phase transition lines upwards.

Polydispersity destabilizes the copolymer system.

Higher order correlations are significantly affected by Laser distribution parameters.

Abstract

Phase behavior of AB-multiblock copolymer melts which consists of chains with Laser distribution of A and B blocks have been investigated in the framework of the mean-field theory, where the polydispersity of copolymer is a function of two parameters K and M. The influence of the Laser distribution on higher order correlation functions (up to sixth order) are computed for various values of K and M, and their contributions on the phase diagrams and phase coexistence are presented. It is shown that, with increasing polydispersity (decreasing K and increasing M) the transition lines of all phases shift upwards, consequently polydispersity destabilize the system.