THE SHORT AND LONG-TERM PROPERTIES OF A LIQUID-CRYSTALLINE POLYMER ATELEVATED-TEMPERATURES - CHARACTERIZATION AND MODELING

Tensile and short term (24 h) creep tests were performed on Xydar G930 , a liquid crystalline polymer (LCP) with 30 wt.% glass filler, at tem peratures and stress levels ranging from room temperature to 175 degre es C and 0.3 fraction ultimate tensile strength (UTS) to 0.8 fraction UTS, respectively. Temperature was found to have an affect on the shor t term tensile properties. The resulting strain vs time creep curves s howed the expected dependence of creep strain on temperature and stres s level. Creep compliance curves were derived from the creep curves an d showed distinctively nonlinear viscoelastic behavior at all stress l evels and temperatures. Creep compliance was found to follow a power l aw in time. The power law was used to model the stress dependence of c reep and the Arrhenius equation was employed to model the temperature dependence up to 120 degrees C. A significant reduction in creep resis tance was observed at 175 degrees C. Time-temperature-stress-superposi tion was used to show that the material followed power law behavior up to 1000 h.