Branched Block Copolymers Of Computer Simulation

The studies on polymer phase structures are the most important projects in the polymer science. Understanding the dependence of polymer phase structure on detail molecular parameters is critical and necessary to be resolved before real application. Due to the great difficulties in experiments and theory, people hope to resolve them through computer simulation, which can overcome the disadvantages of theory and experiments, and provide more valuable data for researchers. In this thesis, computer simulation is applied to study self-assembly of comb block copolymer and "Y" A₂B copolymer. The contents and results are as follows.1.Using the dynamic mean-field density functional method, we explore microphase of ABC comb copolymers in two-dimensional space. Simulations are carried out for two different architectures copolymer. One is symmetry comb copolymer and the other is asymmetry comb copolymer. By systematically varying the Flory-Huggins parameters, we observe the microphase separation and microstructures self-assembled by the two systems. For asymmetry comb copolymer melts, some microphases patterns, such as corolla, pulse-like and hexagon core are discovered, while lamellar and kitting-nap are found as main patterns for symmetry comb copolymer. Phase diagrams of two different systems are made, which illustrate the dependence of phase structure on the chain architecture and Flory-Huggins parameters. When both volume fractions and interaction energies of three species are same for the two systems, the stable microphases depend greatly on their architectures.2.The microphase diagram of a special A₂B copolymer melts is presented by...