Improving the flame retardancy and smoke suppression of PVC membrane material by incorporating zinc borate-modified diantimony trioxide

Abstract

Zinc borate (ZB) based diantimony trioxide(Sb2O3) are environment-friendly flame retardant for flexible PVC membrane material. Also, they usually exhibit high flame retardancy and smoke suppression properties. The maximum LOI value of PVC/20 wt% ZB-Sb2O3 membrane material reached 37.5% and passed the UL 94 V-0 rating. An obvious synergistic effect between ZB and Sb2O3 was observed by LOI, SDR and TG. Moreover, remarkable decreases in the smoke density were observed when ZB-Sb2O3 was incorporated into PVC. The addition of ZB and Sb2O3 greatly increased the amount of residual char and apparently improved the mechanical properties of PVC membrane material. Additionally, the structure and morphology of the residual chars have been studied by FTIR, EDX and SEM. The results illustrated that the flame retardancy of ZB-Sb2O3 was mainly exerted in the condensed phase.