材料期刊网

为实现聚乙烯单聚合物复合材料（ PE SPC）的嵌件注射成型，研究基体与增强体间的界面非常关键.本文采用超高分子量聚乙烯（ UHMWPE）纤维增强低密度聚乙烯（ LDPE）基体，对纤维和基体进行了差示扫描量热仪测试，在偏光显微镜下模拟了基体与纤维的复合过程，研究不同因素对复合材料界面结晶形态的影响.根据DSC确定了UHMWPE和LDPE复合的温度范围在110.98~147.14℃；合适的温度和剪切作用都有利于界面横晶的产生，从而使基体和纤维产生更好的粘结，提高复合材料的力学性能；温度比剪切的影响更大，注射温度设置在125~135℃可在保证纤维与基体复合的情况下不破坏纤维的增强作用；纤维丝之间会相互影响界面结晶形态，部分界面有横晶产生，说明在实际注射成型过程中纤维束或纤维布的结构对基体渗透和界面形成有较大影响.

In order to realize the insert injection molding of polyethylene ( PE ) single-polymer composite (SPC), it is important to study the interfacial morphology of the matrix and reinforcement. In this study, the ultra-high molecular weight polyethylene ( UHMWPE ) fiber was used to reinforce low density polyethylene (LDPE) matrix. Thermodynamic properties of the fiber and matrix were tested by DSC. Polarizing microscope was adopted to simulate the molding process of PE SPC. The effects of different factors on the interfacial crystal morphology were investigated. The research results it could provide theoretical guidance for the insert-type injection molding process of PE SPC. The temperature range for the UHMWPE/LDPE composite was determined as 110.98~147.35℃ by the DSC results. Appropriate temperature and shear rate are conducive to the formation of interfacial transcrystallinity, which can produce better bonding between matrix and fiber and improve the mechanical properties of composites. Temperature has much greater influence than the shear, the injection temperature from 125 to 135℃ could be used to confirm the UHMWPE/LDPE composite without fiber melting. The effects on interface crystal morphology among fibers with each other are obvious, interfacial transcrystallinity could be found only around part filaments. It indicates that the structure of fiber bundles or fabric has great effect on the permeability of the matrix and the interface between the fiber and matrix.