The miscibility and structure ofA-B copolymer/C homopolymer blends with special interactions were studied by a Monte Carlo simulation in two dimensions. The interaction between segment A and segment C was repulsive, whereas it was attractive between segment B and segment C. In order to study the effect of copolymer chain structure on the morphology and structure of A-B copolymer/C homopolymer blends, the alternating, random and block A-B copolymers were introduced into the blends, respectively. The simulation results indicated that the miscibility of A-B block copolymer/C homopolymer blends depended on the chain structure of the A-B copolymer. Compared with. alternating or random copolymer, the block copolymer, especially the diblock copolymer, could lead to a poor miscibility of A-B copolymer/C homopolymer blends.Moreover, for diblock A-B copolymer/C homopolymer blends, obvious self-organized core-shell structure was observed in the segment B composition region from 20% to 60%. However, if diblock copolymer composition in the blends is less than 40%, obvious self-organized core-shell structure could be formed in the B-segment component region from 10 to 90%.Furthermore, computer statistical analysis for the simulation results showed that the core sizes tended to increase continuously and their distribution became wider with decreasing B-segment component.
Multi-scales relaxation processes of short fiber of a nematic liquid crystalline copolymer(LCP)in polycarbonate matrix were investigated.First,the structure relaxation of LCP was studied by rheology.The relaxation spectrum of the nematic liquid crystalline copolymer at 295℃was calculated from the combined dynamic modulus.There are three kinds of relaxation mechanisms for nematic liquid crystalline copotymer:the relaxation of chain orientation,the relaxation of deformed polydomains and the coalescence of ...