A mussel-inspired intumescent flame-retardant unsaturated polyester resin system

A mussel-inspired intumescent flame-retardant (MIFR) was introduced into unsaturated polyester resin (UPR) to modify its flame retardancy. Its flame retardant and smoke suppression properties were studied by cone calorimetry test (CCT) and limiting oxygen index (LOI), UL-94, and the flame-retardant mechanism was studied by scanning electron microscopy and thermogravimetric analysis (TG). The LOI data showed that MIFR could greatly enhance the flame retardancy of UPR. The UPR composites with 10 mass% of MIFR have a LOI 27.8% and passes the UL-94 V-0 test without melt-dripping, while that for UPR-MAPP is only 25.5% with V-2 test at the same content. The mechanical properties of UPR-MIFR composites are higher than those of UPR-MAPP composites. The CCT revealed that MIFR can significantly decrease the heat release and the amount of smoke production. The TG test showed that MIFR could catalyze degradation of UPR composites and promote the char formation in the combustion process of UPR. In summary, the microencapsulation coating of the TA-Fe3+ modified the surface of MAPP enhanced the mechanical properties, flame retardancy and smoke suppression.