HDPE含量对熔纺UHMWPE/HDPE纤维晶体结构及力学性能的影响

Influence of HDPE Content on the Crystallization and Mechanical Properties for the Melt Spun UHMWPE/HDPE Blend Fibers

高密度聚乙烯(HDPE)的含量对超高分子量聚乙烯(UHMWPE)/HDPE混合纤维的结构和力学性能有重要影响。通过声速取向测试、扫描电子显微镜(SEM)、差示扫描量热仪(DSC)、X射线衍射仪(XRD)以及纤维力学测试等方法研究了HDPE的含量对UHMWPE/HDPE共混纤维的微观结构及力学性能的影响。结果表明,当HDPE的质量分数为40%时,HDPE具有良好的润滑作用,能够有效促进UHMWPE/HDPE纤维的分子链沿轴向取向,声速取向因子达96.73;纤维的内部形成了细长的晶粒,纤维的结晶度和晶体取向度显著提高,分别达到64.14%和0.98;细长晶粒在径向上紧密排列,在轴向上由非晶区的伸展分子链连接,这种结构能够更好地承载力学性能,因此,纤维获得最佳的力学性能,其拉伸强度可以达到1204 MPa,初始模量可以达到20.7 GPa。

The structure and mechanical properties of ultra-high molecular weight polyethylene( UHMWPE)/high-density polyethylene( HDPE) blend fibers were greatly affected by the content of HDPE. The influence of HDPE content on the microstructure and mechanical properties of UHMWPE/HDPE blend fibers was studied by sound velocity orientation test,scanning electron microscope( SEM),differential scanning calorimeter( DSC),X-ray diffractometer( XRD) and fiber strength test. It was found that,when the mass ratio of HDPE was 40%,the orientation of the molecular chains of UHMWPE/HDPE fibers in the axial direction could be effectively promoted,and the sound velocity orientation factor was 96. 73;slender grains were formed,and the degree of crystallinity and crystal orientation were significantly improved,which were 64. 14% and 0. 98,respectively;the slender crystal grains were closely arranged in the radial direction and connected by the stretched molecular chains in the axialdirection. Better mechanical properties could be supported by this structure,so the best mechanical properties with a tensile strength of 1 204 MPa and an initial modulus of 20. 7 GPa were obtained.