Premium
Molecular orientation and mechanical properties of polymer blends of PBT and a liquid crystalline polyester
Author(s) -
Moon HyukSoo,
Park JungKi,
Liu JuHwan
Publication year - 1996
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19960118)59:3<489::aid-app14>3.0.co;2-p
Subject(s) - materials science , miscibility , thermotropic crystal , polyester , liquid crystal , polymer , polymer blend , fourier transform infrared spectroscopy , polarized light microscopy , composite material , polymer chemistry , chemical engineering , spinning , liquid crystalline , copolymer , physics , optoelectronics , optics , engineering
A thermotropic liquid crystalline polyester (LCP) based on 4‐hydroxyacetophenone azine and sebacoyl dichloride was synthesized via a low‐temperature solution route. The liquid crystalline polymer was characterized by 1 H‐NMR, DSC, GPC, and polarizing microscopy experiments. The LCP was melt‐blended with poly(butylene terephthalate) (PBT), followed by the melt‐spinning process at take‐up speeds ranging from 14 to 50 m/min. We analyzed the molecular orientational order of LCP and PBT in as‐spun fibers of the LCP/PBT blends by the attenuated total reflection (ATR) FTIR dichroism technique and WAXS. The order parameter ( S ), representing the molecular orientational order, of LCP in the polyblend fibers increased as the employed LCP amounts and the draw ratio increased. Moreover, the order parameter of PBT in the blends increased dramatically when sufficiently large amounts of LCP (over 50 wt %) were employed, especially for highly drawn fibers, which suggested a considerable miscibility between LCP and PBT. The thermal behavior of the blends investigated by DSC also indicated that the synthesized LCP was miscible, at least partially, with PBT. All these results correlated with the enhancement of mechanical properties observed for higher concentrations of LCP in the blends and for highly drawn samples. © 1996 John Wiley & Sons, Inc.