PREPARATION AND PROCESSING OF MOLECULAR COMPOSITES OF RIGID-ROD AND FLEXIBLE-CHAIN POLYMERS FROM SOLUBLE COMPLEXES

Molecular composites of rigid-rod poly(p-phenylene-2,6-benzobisthiazol e) (PBZT) and flexible-chain chain polyamides, nylon 66 and poly((trim ethylhexamethylene)terephthalamide) (PTMHT), have been prepared from t ernary solutions of their coordination complexes in organic solvents a nd characterized. The measured ternary phase diagrams of the PBZT/poly amide/nitromethane-Lewis acid systems showed that the critical concent ration for anisotropic phase appearance was as high as 8-10 wt %, depe nding on the rod/coil ratio and the Lewis acid (AlCl3 or GaCl3) used. These critical concentrations are significantly higher than those atta inable in similar ternary solutions of the polymers in protonic acid s olvents. Films and coatings of PBZT/nylon 66 and PBZT/PTMHT molecular composites prepared from isotropic solutions were shown to be uniform with molecular level dispersion by various morphological characterizat ion techniques. The favorable ternary solution phase equilibria and th e processability from organic solvents make the present complexation m ediated processing a promising approach for preparing polymer-based mo lecular composites for structural, optoelectronic, and photonic applic ations.