HEAT-TREATMENT STUDIES OF A TLCP FIBER

This work deals with the heat treatment of fibers and nonoriented spec imens made of the thermotropic liquid crystalline polymer Vectra A900 in the light of tensile properties and DSC measurements. In calorimetr ic measurements, there seem to be some differences in the effects of t he treatment between macroscopically isotropic (nonoriented) and highl y oriented fiber specimens. Nonisothermal treatments also produce some effects on the tensile properties, which may be attributable to the t hermal history of samples. Under the conditions of this study, a multi step treatment, ending at a final stage where the temperature was high er than the original melting point of the polymer, did not cause any a cceleration in the rate at which tensile properties increase. (C) 1993 John Wiley & Sons, Inc.