Abstract
PVA compounds plasticized by various amounts of glycerin were spun into fibers by melt process and followed by the extraction with methanol and the drawing in a hot air. The structure and properties of the fibers were studied by a x-ray instrument, a polarizing light microscope, a density gradient column, a differential thermal analyser and a tensile tester. The best spinnability was found for the compound containing 27 wt% glycerin. However, the exact glycerin content of the as-spun fiber prepared from this compound was 11 wt%. The drastic decrease in glycerin content might be attributed to the vaporization during the melt spinning and the bleeding after the melt spinning. The extracted fiber could be drawn by around 7 times at 220°C, while the plasticized as-spun fiber was drawable up to 6 times. The drawn extracted fiber had the higher anisotropy evaluated by polarized microscopy but the lower crystalline orientation by x-ray analysis than those of the extracted fiber. This may be responsible to the mobility and the orientation of amorphous chains in both plasticized and extracted fibers.
