Cross-linking reaction of LDPE and the behavior of decomposition products from cross-linking agents

摘要

Cross-linked polyethylene (XLPE) insulated power cables may occasionally be exposed to high temperatures above 150/spl deg/C for relatively short periods of time. Numerous microvoids are sometimes observed in the XLPE heated under such con ditions. Studies were carried out to clarify the mechanism of this void forma tion in the XLPE insulation. A series of experiments revealed that void for mation. was caused by water generation in the XLPE because of the dehydration of cumyl alcohol produced from the cross-linking agent (dicumyl peroxide: DCP). This reaction may produce /spl alpha/-methylstyrene simultaneously with water. The generation of water was evidently catalyzed by acidic antioxidants while the dehydration was suppressed using certain antioxidants which possessed weak H/sup +/ donating properties.