Investigation on novel flame retardant low-density polyethylene composites based on THEIC and MCAPP

The low-density polyethylene (LDPE) composites with excellent fire resistance were fabricated based on the novel intumescent flame retardant (IFR) composed of tris(2-hydroxyethyl) isocyanurate (THEIC) and silica-gel microencapsulated ammonium polyphosphate (MCAPP). The influence of the IFR with varied mass ratio of THEIC and MCAPP on the flame retardancy and thermal properties of LDPE composites were investigated. Results show that the introduced IFR improves the flame retardancy significantly, and the highest limited oxygen index of 33.2% is obtained in the case with MCAPP/THEIC equaling 2:1 (LDPE3), achieving V-0 rating of UL-94. The peak heat release rate and total heat release of LDPE3 are decreased remarkably by 74.8% and 71.9%, respectively, in comparison with pure LDPE. Thermogravimetric analysis demonstrates LDPE composites with IFR having the dramatic enhanced thermal stabilities than that of pure LDPE at high temperature. This study provides an valuable approach to prepare the intumescent flame retardant LDPE composites.