PROPERTIES OF FLAME-RETARDING BLENDS OF POLYCARBONATE AND POLY(ACRYLONITRILE-BUTADIENE-STYRENE)

Limiting oxygen index (LOI) value, glass transition temperature (T-g) thermal degradation profile, morphology, and tensile strength and elon gation at break of the flame-retarding polycarbonate (PC)-poly(acrylon itrilebutadiene-styrene) (ABS) (7/3) blends were studied. The flame re tardants used were huntite-hydromagnetite compounds (HHM), triphenyl p hosphate (TPP), zinc stannate, and antimony trioxide. The LOI values w ere increased with the increase of TPP content, but they did not chang e significantly when the HHM was used as a flame retardant. Glass tran sition temperatures of the name-retarding PC-ABS (7/3) blends were dec reased significantly when TPP was added to the blends. This is mainly due to the plasticizing effect of the TPP on the PC-ABS (7/3) blends. In the flame-retarding PC-ABS (7/3) blends, the LOI value, tensile str ength, and elongation at break were measured and found to be 24.6 - 31 .6%, 41.4 - 50.3 MPa, and 2.16 - 33.7%, respectively. These LOI values and mechanical properties were achieved when the TPP, zinc stannate, and antimony trioxide were used as flame retardants, and when dodecylb enzenesulfonic acid sodium salt and dimethylsulfone were used as addit ives into the PC-ABS (7/3) blends.