Preparation of a novel flame retardant TGICA-DOPO and its effects on the properties of vinyl ester resin

A novel flame retardant containing P and N was successfully synthesized via the addition reaction between triglycidyl isocyanurate (TGIC), acrylic acid and 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). A flame retardant composite material TGICA-DOPO/vinyl ester resin (VER) was prepared by applying it to VER. The structure of TGICA-DOPO is characterized by FTIR, ¹H and ³¹P nuclear magnetic resonance (NMR). The flame retardancy and thermal properties of TGICA-DOPO/VER resin system were respectively investigated by limited oxygen index (LOI) measurement, TGA and DMA. The results show that the LOI value of the resin system containing 30wt% TGICA-DOPO is improved to 35. TGA results indicate that the char yields of VER casting containing 25wt% TGICA-DOPO under 800℃ is increased by 322%. The FTIR and SEM results indicate that TGICA-DOPO promotes the formation of continuous, compact and intumescent char layer which can reduce the efficiency of heat-and oxygen-exchange.