Abstract
The crystal lattice structure, thermal behavior, molecular orientation, and mechanical property of spun strands of a thermotropic liquid crystalline polymer (LCP) were studied with wide angle X-ray diffraction, differential scanning calorimetry, birefringence, and tensile tests. The purpose of this work is to elucidate the effects of draw-down ratio and annealing conditions on the structural development in the LCP strands. Relaxation of the lateral packing of PHB molecular chain in a copolymer of p-hydroxibenzoic acid and ethylene terephtalate (60/40) mole%) occurred in the course of annealing treatment. The annealing treatment slightly increased the crystalline orientation factor, whereas total molecular orientation was decreased by annealing. In addition, the relationship between initial modulus and annealing treatment was sensitive to total molecular orientation. The initial modulus increased with increase in the draw-down rate. The endothermic behavior at about 20$0^{\circ}C$ is due to the PET regions with the incorporation of PHB segments causing a diluent effect.
