Study On Environmental Stress Cracking Resistance Of Polyethylene Cable Sheath

In this paper, the problem of environmental stress cracking of polyethylene cable sheathing is studied. Polyethylene material because of its excellent mechanical strength, toughness, heat resistance and electrical insulation properties, so the wire and cable sheath has been widely used. But in the application process the resistance to environmental stress cracking performance is poor,This seriously affecting the service life of the cable, thus limiting the extensive use of polyethylene materials.In order to analyze the environmental stress cracking mechanism of polyethylene cable sheath, we have analyzed cracking and non-cracking polyethylene cable sheathing particles and parts that provided by enterprises.The effects of high density polyethylene and linear low density polyethylene on the environmental stress cracking of cable insulation sheath were studied by FT-IR and DSC. The results found that high-density polyethylene easily lead to cable material cracking; The thermal stability of the cable insulation sheath was studied by TG. It was found that improving the antioxidant efficiency of the antioxidant could improve the environmental stress cracking performance of the material. The gel content and SEM tests showed that the crosslinking degree of the material and its resistance to environmental stress cracking are related, high degree of cross-linking of the material resistance to environmental stress cracking performance is also excellent.In order to analyze the effect of different composition formulations on the environmental stress cracking performance of polyethylene cable sheaths, different groups of experimental samples were prepared by twin screw blending. The mechanical properties, heat resistance,shrinkage resistance and environmental stress cracking resistance of different compositions were studied. It was found that the mechanical properties of the cable material decreased with the increase of LLDPE and EVA content, but the shrinkage resistance and resistance to environmental stress cracking of the sheathing material were greatly improved. It was found that the shrinkage resistance and resistance to environmental stress cracking of the sheathing material increased and then decreased with the increase of DCP content.