【摘要】 针对传统方法成形管材周向强度低的问题,利用自制的剪切拉伸双向复合应力场挤管装置,在向相对低分子量的通用级高密度聚乙烯中添加少量相对高分子量的高密度聚乙烯(HMWPE)进行诱导结晶的方法自增强管材的周轴两向强度。拉伸测试表明,添加6%(wt)HMWPE混合体系管材的周向和轴向力学性能分别提高了49.0%和6.9%。差示扫描量热法(DSC)、扫描电子显微镜(SEM)和X射线广角衍射(WAXD)测试表明:管材周轴两向自增强的产生是由于在复合应力场下大分子发生取向和结晶度提高所致。更多还原

【Abstract】 In order to resolve the problem that circumferential tensile strength of conventional forming pipe is low,a self-made shear-tensile bidirectional combined stress field pipe extrusion equipment was used to engender induced crystallization to produce bidirectional self-reinforcement pipes by adding a small amount of relatively high molecular weight HDPE(HMWPE) to relatively low molecular weight general purpose HDPE.Results of tensile testing showed that the circumferential and axial tensile strength of the system with 6%(wt)HMWPE increases by 49.0% and 6.9%,respectively.Differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and wide-angle X-ray diffraction(WAXD) test showed that macromolecule orientation under a complex stress field and the increase of crystallinity result in the bidirectional self-reinforcement of pipe.更多还原