Influence of Crosslinking Parameters on the Space Charge Characteristics of Hindered Phenol Antioxidant Grafted Polyethylene

Cross-linked polyethylene (XLPE) insulation materials are used widely in high-voltage cables. To slow down the thermal-oxidative aging of XLPE, it is common practice in engineering to add an appropriate amount of antioxidant during the preparation of XLPE masterbatches. Antioxidant 300 was selected and added to low-density polyethylene, with the antioxidant 300 being grafted onto the polyethylene molecular chains through a chemical reaction during the crosslinking process. The effects of different crosslinking temperatures and times on the crosslinking rate, mechanical properties, physicochemical properties, and space charge distribution characteristics of the XLPE were studied. The results show that with the increase of crosslinking temperature or the extension of crosslinking time, the gel content and tensile strength of XLPE increase, while the crystallinity decreases, and the height of the hydroxyl absorption peak in the infrared spectrum curve reduces, leading to increasingly severe electric field distortions caused by space charges. These findings provide data support for scientific research and engineering fields.