THE THERMAL-DEGRADATION OF ACRYLONITRILE-BUTADIENE-STYRENE TERPOLYMER AS STUDIED BY TGA/FTIR

The thermal degradation of acrylonitrile-butadiene-styrene (ABS) terpolymer has been studied by TGA/FTIR. The degradation of ABS is compared with that of polystyrene, polybutadiene, polyacrylonitrile (PAN), and styrene-acrylonitrile (SAN) copolymer. A small amount of acrylonitrile monomer is eliminated from PAN, SAN, and ABS. The grafting of butadiene on to SAN stabilizes the butadiene structure, since the evolution of butadiene begins 50 degrees C higher than in the homopolymer. The evolution of aromatics begins about 20 degrees C lower in ABS than in SAN, so the presence of the butadiene destabilizes SAN. The evolution of acrylonitrile begins at essentially the same temperature in ABS as in SAN. There are some significant effects on the degradation produced by grafting SAN onto polybutadiene but the degradation may be understood by considering the degradation of its components.