Heat treatment studies of a TLCP fiber

This work deals with the heat treatment of fibers and nonoriented specimens made of the thermotropic liquid crystalline polymer Vectra A900 in the light of tensile properties and DSC measurements. In calorimetric measurements, there seem to be some differences in the effects of the treatment between macroscopically isotropic (nonoriented) and highly oriented fiber specimens. Nonisothermal treatments also produce some effects on the tensile properties, which may be attributable to the thermal history of samples. Under the conditions of this study, a multistep treatment, ending at a final stage where the temperature was higher than the original melting point of the polymer, did not cause any acceleration in the rate at which tensile properties increase.