Thermal analysis studies on thermoplastic rigid rod molecular composites

Rigid rod molecular composites involve molecular level mixing of two polymers having greatly disparate chain conformations (one rodlike and one flexible coil like). Morphology studies have shown that in such materials the bundle diameter of these rigid rod molecules is less than 5 nm. The rigid rod molecule used is poly(para-phenylene benzobisthiazole) (PPBT). The thermoplastic flexible polymer matrix is Nylon-66, DuPont's Zytel 42. Thermal analysis studies on these materials indicate that the expected T_g shifts, as observed for blends of two flexible polymers, and depression of T_m with increased rod molecule composition does not occur.