Dynamical Mechanical Properties of Main Chain Liquid Crystalline Polymers

Abstract

The dynamical mechanical properties as well as the dielectric relaxation properties of liquid crystalline main chain polymers were determined in a temperature range from -150 [ddot] up to 200 C[ddot] both for rigid as well as for semiflexible chain molecules. The presence of a secondary relaxation process well below room temperature and of a primary glass rglaxation at temperatures between 65 and 110 [ddot] C was observed for these polymers These processes were found to couple strongly to the dynamical mechanical properties as well as to the dielectrical properties. A surprising finding is the large relaxation strength and the corresponding energy dissipation associated with the low temperature β- relaxation in these polymers with restricted chain flexibility.