国产与进口基料热塑性聚乙烯基电缆绝缘料性能对比研究

Comparative study on performance of thermoplastic polyethylene-based cable insulating mateirals with domestic and imported base materials

聚乙烯基非交联电缆绝缘材料具有优于XLPE的电气性能和力学性能,加工工艺简单、生产能耗低并可回收,是最具应用前景的新型环保电缆绝缘材料之一。本文采用国产基料制备不同配比的LLDPE/HDPE共混绝缘材料,对其电气、力学、流变和抗热氧老化性能进行测试,并与进口基料制备的共混材料进行对比。结果表明:国产与进口共混材料都在LLDPE、HDPE质量比为7∶3时表现出最佳的电气性能和力学性能。最优质量比下国产共混材料的电气性能与进口共混材料表现相近,但拉伸强度较低。在抗热氧老化性能上,国产共混材料与进口共混材料相比有明显差距。通过分子量及其分布测试、红外光谱分析发现,国产LLDPE的支化度和进口LLDPE相近,但其分子量分布范围更宽,且低分子方向存在明显长尾分布,这可能是导致国产共混材料拉伸强度和抗氧化性能较低的原因之一。

Polyethylene-based non-crosslinked cable insulation materials have better electrical and mechanical properties,simpler processing,lower energy consumption than XLPE,and can recycle,which are one of the most promising new environmentally friendly cable insulation materials.In this paper,LLDPE/HDPE blending insulating materials with different ratios were prepared using domestically produced base materials,and their electrical,mechanical,rheological,and thermal and oxygen aging resistance properties were tested and compared with the blending materials prepared by imported base materials.The results show that both the domestic and imported blending materials have the best electrical properties and mechanical properties when the mass ratio of LLDPE and HDPE is 7:3.The electrical properties of the domestic blending materials are similar to those of the imported blending materials at the optimal ratio,but the tensile strength is lower.There is a significant difference between domestic and imported blending materials in thermal and oxygen ageing resistance.Through the molecular weight and its distribution test,infrared spectroscopy analysis,it is found that the branching degree of domestic LLDPE is similar to that of imported LLDPE,but its molecular weight distribution range is wider and there is an obvious long-tailed distribution in the direction of low molecules,which may be one of the reasons for the lower tensile strength and antioxidant properties of domestic blending materials.