Structure and properties of blend fibers from poly(ethylene terephthalate) and liquid crystalline polymer

Abstract

The structure and properties of the as-spun fibers of poly(ethylene terephthalate) (PET) blends with a thermotropic liquid crystalline polymer (LCP), Vectra A900, were studied in detail. The DSC results indicate that the LCP component may act as a nucleating agent promoting the crystallization of the PET matrix from the glassy state but which inhibits its crystallization from the melt due to the existence of an LCP supercooled mesophase. The effect of the drawdown ratio on the orientation of the as-spun blend fibers is highly composition-dependent, which is mainly associated with the formation of LCP fibrils during melt spinning. The modulus of the as-spun blend fibers has a significant increase as the content of LCP reaches 10%, while the tensile strength has a slightly decreasing tendency. The mechanical properties of the as-spun blend fibers could be well improved by heat treatment because of a striking increase in the crystallinity of the PET matrix. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 217–224, 1997