Synthesis and properties of phosphorus and nitrogen containing intumescent flame-retardant curing agent for epoxy resin

Abstract

A kind of intumescent flame-retardant curing agent (PCDSPB) was synthesised by using pentaerythritol, phosphorus oxycholoride, cyclohexane-1,3-diyldimethanamine (1,3- BAC) as raw materials and the structure was characterised by FTIR and MS. The composite materials were investigated by using TG, TG-FTIR, LOI, UL-94, SEM, and CCT. The results show that the filling of PCDSPB can improve the flame resistance of EP composites. When the phosphorus content of the composite system was 1.74 wt-%, the initial weight loss temperature was 299°C and the char yield was 26.3% at 600°C. Tensile strength was 35.4 MPa, impact strength was4.3 kJ m−2, LOI was 27.9, and the UL94 passed V-0 level. In the CCT, the peak heat release rate reduced to 276.0 kW m−2(EP-2) from 622.8 kW m−2 (EP-0), the total heat release decreased from 121.8 MJ m−2 (EP-0) to 89.5 MJ m−2 (EP-2). Therefore, the PCDSPB is a good intumescent flame-retardant curing agent for EP.