Non-halogen Flame Retardant PC/ABS Blend

Polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) copolymer blend is an important industrial plastic alloy which is widely applied to automotive, electrical and electronic, mechanical areas due to its overwhelming advantages. However, the addition of ABS causes deterioration of flame retardancy for the PC/ABS blend, limiting the application of PC/ABS. Therefore, it’s significant to reduce flammability of PC/ABS blends. For the demand of environmental protection, aryl phosphate ester is an effective substitute for halogen flame retardant. In this research, aromatic phosphate ester was used as the flame retardant for PC/ABS blend.Firstly, triphenyl phosphate (TPP) was chosen as a flame retardant in PC/ABS blend. Incorporation of TPP resulted in a remarkable improvement in UL 94 and LOI tests. When 20 shares TPP adding to PC/ABS blend, the rate of UL 94 test became V-0, and the LOI value was raised to 26.6%. The result of thermo-gravimetric analysis(TGA) showed that TPP improved the thermal stability, and the yield of residues increased. TPP as a plasticizer can raise the notched impact strength, tensile strength and elongation at break. Using methyl methacrylate-butadiene-styrene (MBS) as the compatibilzer, the flame retardancy, thermal properties and mechanical properties showed a slight deterioration.Secondly, acrylonitrile-butadiene-styrene high-rubber powder (ABS-HRP) and styrene-acrylonitrile (SAN) were chosen to substitute ABS. When the proportion of PC/ABS-HRP/SAN was 70/27/3, PC/ABS-HRP/SAN blend had the excellent integrated mechanical properties to study the flame retardancy. In flame retardant tests, TPP showed a great flame-retarded effect. UL 94 and LOI tests displayed that 20 shares of TPP leading to V-0 rating and 27.6% LOI value. Also we found that TPP could dramatically reduce the heat release rate,mass loss rate in Cone test. TGA indicated that TPP could markedly enhance the thermal stability. But the different adding amount of TPP could cause a different trend of the thermal decomposition curve, which demonstrated the flame-retardant mechanism of TPP influenced by the adding amount. TPP obviously degradation the notched impact strength of PC/ABS-HRP/SAN blends.Finally, PC/ABS-HRP/SAN/TPP/a-ZrP systems were studied to understand for their on thermal properties and flame retardancy. TGA in nitrogen atmosphere indicated that TPP and a-ZrP could markedly enhance the thermal stability, especially at high temperature area. TPP and a-ZrP did not show a great synergistic effect in UL 94 and LOI tests. Cone result indicated that TPP and a-ZrP not only enhanced the flame retardancy of PC/ABS-HRP/SAN, but extended the burning time and slowed down the process of combustion.