PHASE-BEHAVIOR AND PHASE-SEPARATION IN BLENDS OF A LIQUID-CRYSTALLINEPOLYMER AND AN AMORPHOUS POLYMER CONTAINING HYDROGEN-BONDING INTERACTION

The phase behavior and thermally induced phase separation in blends of poly{styrene-co-[p-(2, droxy-1-trifluormethyl)ethyl-alpha-methylstyre ne]} (PS(OH)) and a thermotropic liquid crystalline polymer (LCP) were studied by optical microscopy (OM), infrared spectroscopy (TR) and ti me-reserved light scattering (TRLS). PS(OH) contains strong proton-don ating groups -C(CF3)(2)OH, and the LCP is poly[p-(tert-butyl)phenylene fumarate] (PBPF), which is soluble in common solvents. For blends of PS(OH)/ PBPF, the miscible region was found only at high PBPF composit ions and law temperature due to intermolecular hydrogen bonding betwee n -C(CF3)(2)OH groups of PS(OH) and the phenolic OH end-groups of PBPF according to IR. The PS(OH)/PBPF blend undergoes phase separation via spinodal decomposition (SD) during isothermal annealing in the two-ph ase regime of phase diagram. The SD yielded unique Vv and Hv scatterin g patterns, which can be attributed to regular periodic phase-separate d structures composed of an anisotropic phase and an isotropic phase. Preliminary studies on the SD process by TRLS showed that the phase se paration spontaneously occurs at a certain time, that might be associa ted with the presence of the LCP.