Study on Surface Yellowing Behavior of White Low Smoke Halogen-Free Flame Retardant Polyolefin Insulating Material

The surface color of white low-smoke halogen-free flame-retardant polyolefin insulation materials tend to be dark and yellow during application, which leads to suspicious performance of the insulation materials from customers. In this work, white low-smoke halogen-free flame-retardant polyolefin insulating material was taken as the research object, the photoaging discoloration was conducted under ultraviolet radiation, and the discoloration behavior was studied by polarizing microscope, X-ray photoelectron spectrometer, Fourier infrared spectroscopy. The results show that the assistant crosslinker triallyl isocyanurate (TAIC) is the dominant for discoloration, the migration of TAIC to the surface of the insulation and the chemical bond change are the key factors.