Effect of various combinations of flame-retardant fillers on flammability of radiation cross-linked poly(vinyl chloride) (PVC)

摘要

Various formulations of radiation cross-linked poly(vinyl chloride) (PVC) were prepared to improve the flame retardancy for wire and cable insulation applications. Limiting oxygen index (LOI) was used to characterize the flammability of the developed formulations. The effect of different plasticizers, dioctyl phthalate (DOP), di-isodecyl phthalate (DIDP) and tri-2-ethylhexyl tri-mellitate (TOTM) and various combinations of different flame-retardant additives, namely Sb_2O_3, zinc borate, Al(OH)_3 and Mg(OH)_2 on the mechanical properties and flammability was investigated. The influence of radiation dose on the mechanical properties was minimal at room temperature, but more prominent after thermal aging for 168 h at 136℃. The highest LOI was 31% for PVC formulations containing DOP as a plasticizer and TMPTA at an absorbed dose of 60 kGy. Both DTG peak maxima and temperature for loss of 50% mass were investigated for selected formulations. No apparent influence of plasticizer type or irradiation dose on these thermal properties was observed.