Synthesis and characterisation of unsaturated polyester resin /Aluminium hydroxide/magnesium hydroxide fire retardant composite

Aluminium hydroxide (Al(OH)3) and Magnesium hydroxide (Mg(OH)2) can be used as the alternative for fire retardant additive which can improve the fire retardancy without giving the bad effect on health. In this research, the synthesis of fire retardant UPR based composite has been conducted by varying the concentration of Al(OH)3/Mg(OH)2 additive. Fire retardancy was observed by using UL-94V standard. The thermal degradation behaviour of composite was studied by thermal gravimetric (TG) and differential scanning calorimetry (DSC) analysis while the mechanical properties were observed from tensile strength and hardness testing. The best fire retardancy was obtained from the composite with concentration of Al(OH)3 40 %/ Mg(OH)2 10 % and resulted V-0 flammability rating. Combination of Al(OH)3 40 %/ Mg(OH)2 10 % could improve the thermal stability of composite by reducing the mass loss rate (MLR) to 4.9 %/min and total mass loss to 77 %, while the tensile strength decreased to 64 % and the hardness improved to 64.5 %. The morphology and mapping of composite showed that Al(OH)3 additive was well-dispersed, while Mg(OH)2 had the tendency to agglomerate.