Thermal and flame retardant properties of novel intumescent flame retardant low-density polyethylene (LDPE) composites

A char-forming agent (CFA) and silica-gel-microencapsulated ammonium polyphosphate (MCAPP) were selected to form novel intumescent flame retardant system (IFRs), and then the influence of this novel IFRs on the thermal and flame retardant properties of low-density polyethylene (LDPE) were studied. The results of cone calorimetry show that the flame retardant properties of LDPE with 30 wt% novel IFR (CFA/MCAPP = 1:3) improve remarkably. The heat release rate peak, total heat release (THR) decreases, respectively, from 1479.6 to 273.5 kW m−2 and from 108.0 to 80.5 MJ m−2. The LDPE composite with CFA/MCAPP = 1:3 has the excellent water resistance, and it can still obtain a UL-94 V-0 rating after treated with water at 70 °C for 168 h.