MOLECULAR DYNAMICS SIMULATION OF A SINGLE-COMPONENT MOLECULAR COMPOSITE - POLY(P-PHENYLENE BENZOBISTHIAZOLE)/META-POLY(ARYL ETHER KETONE) BLOCK COPOLYMER

摘要

Molecular dynamics simulations were performed with a model of a single-component molecular composite in the form of a block copolymer composed of poly(p-phenylene benzobisthiazole) rigid-rod and flexible meta-poly(aryl ether ketone) subunits. The molecular composite concept, applied to improve the compressive strength of rigid-rod polymers and to improve their solubility, relies on a uniform distribution of rods in a coil-like matrix. Pair distribution functions, orientation correlation functions and correlation volumes calculated from equilibrium dynamics trajectories of bulk copolymer, coil homopolymer and rigid-rod homopolymer systems imply that, while inter-rod spacing is only slightly increased in the copolymer, correlation of rod orientation is greatly reduced but to a somewhat lesser extent than previously found for a graft copolymer composed of identical subunits. Conformations of the flexible blocks extend to accommodate the partial rod alignment. The block copolymer topology appears to be a viable alternative to the hairy-rod graft copolymer as a single-component molecular composite. [References: 26]