Morphology of a Phase Separated and a Molecular Composite 30% PBT/70% ABPBI Block Copolymer

摘要

The morphology of a triblock copolymer of rigid-rod poly(p-phenylene benzobisthiazole (PBT) and semi-flexible coil poly (2,3(6)benzimidazole) (ABPBI) was examined by wide angle x-ray scattering and scanning and transmission electron microscopy. When samples were vacuum cast from a solution where the amount of 30% PBT/70% ABPBI copolymer was greater than a critical concentration of 5.8%, large-scale phase separation occurred and a film formed containing 0.1-micron particles and platelets in a ductile matrix. The particles and platelets were composed of well-oriented 10-nm PBT crystallites, while the matrix material was chiefly composed of ABPBI. When the amount of 30%PBT/70% ABPBI copolymer in a solvent was less than the critical concentration, the solution into a water coagulating bath had large scale phase separation inhibited.