挤出成型温度对HDPE双向自增强片材形态结构及性能的影响

THE INFLUENCE OF EXTRUSION TEMPERATURE ON PROPERTIES OF BIAXIAL SELFREINFORCED HDPE SHEETS

采用一种具有复合应力场的挤出口模,在不同的成型温度获得HDPE双向自增强片材,纵向拉伸强度最大提高了近6倍,横向拉伸强度最大提高了78.8%。通过DSC、WAXD、SEM等多种测试手段对试样进行表征,发现随着挤出成型温度的下降,片材的微晶尺寸不断降低,晶胞参数几乎未变化,而结晶度升高,熔点向高温区发生漂移,试样内部有大量的微纤结构存在。

Biaxially selfreinforced HDPE sheets were prepared by the die with complex stress field at different temperature. Longitudinal direction tensile strength increased by almost 6 times, and transverse tensile strength increased by 78.8%. The results of DSC, WAXD, SEM etc. show that with the decrease of processing temperature, Crystallite sizes of selfreinforced sheets decrease and crystallinity increase, however units cell parameters remain invariability. Melt points drift to high temperature and there existes microfibril in the selfreinforced sheets in great bulk.