Scattering Theory and Properties of Block Copolymers with Various Architectures in the Homogeneous Bulk State

Abstract

We have developed a general theory to predict the scattering profiles in the homogeneous state and the phase separation behavior of multiblock copolymers having various architectures such as “linear”, “comb”, and “star”. We found that the scattering intensity versus angle in the homogeneous state has a universal slope at small angles independent of the architecture of the block copolymers. The position of the maximum intensity is almost independent of the number N of sequences, and its amplitude rapidly reaches a plateau value, indicating that the microphase separation for N ≥ 20 is independent of N. Detailed calculations concerning the molecular dimensions and conformations and the thermodynamic behavior of the three types of the multiblock copolymer architectures have been performed based on fundamental variables such as the radius of gyration of each block, the composition, the degree of polymerization, the number of sequences, and the polymolecularity in molecular weight and composition. © 1988, American Chemical Society. All rights reserved.