Irradiation and flame retardant effect of poly[bis(phenoxyphosphazene)] and magnesium hydroxide in LDPE composites

Poly[bis(phenoxyphosphazene)] (PBPP) and magnesium hydroxide (MH) are used as a flame retardant blend with low-density polyethylene (LDPE) for the nuclear cable. This study aims to investigate the effects of PBPP in MH-LDPE blend composites on flame retardance and electron beam irradiation. The structure, morphology, and properties of the blend composites irradiated by an electron beam to different absorbed doses were characterized. The results indicated that PBPP provides lubrication during processing. As the PBPP content in the blend increases the melt flow rate at 20 phr MH, meaning the material is easier to process. The higher the PBPP content, the higher the limiting-oxygen index. The elongation at the break of the PBPP containing composites (at 50 phr MH) was evidently higher than the non-PBPP ones at different absorbed doses by electron beam irradiation. The thermogravimetric analysis results indicated that the improved mechanical property, resulting from electron-beam irradiation, could be attributed to the consumption of PBPP. (authors)