复合应力场下挤出HDPE增强管材性能的研究

用自行研制的能产生先剪切后拉伸的复合应力场挤出成型装置，挤出高密度聚乙烯（HDPE）管材，对管材周向、轴向力学性能进行了初步的研究。与一般牌号为DGDA6098的HDPE比，在HDPE中添加高相对分子质量高密度聚乙烯（HMWHDPE）后，发现HMWHDPE能够诱导HDPE沿应力场方向产生大分子取向和结晶。利用差示扫描量热仪（DSC）和扫描电镜（SEM）检测手段对试样的凝聚态结构进行分析，证实了复合应力场下制备的自增强管材双向力学性能都提高了。

PROPERTIES OF SELF-REINFORCEMENT HDPE PIPE EXTRUDED UNDER COMPLEX STRESS FIELD

HDPE pipes were extruded by using a self-made extrusion die with complex stress field of shearing frist and then drawing during extrusion. The circumferential and axial properties of pipes were studied respectively. In contrast with general HDPE (DGDA6098), when high molecular weight HDPE is added into general HDPE, high molecular weight HDPE contributes to inducing HDPE orientation and crystallization along the stress-field. The aggregate state structure of prod- ucts was studied by DSC and SEM. It is proved that meachanics properties of the self-reinforced HDPE pipes in hoop and axis directions can be achieved under the complex stress field.