Their toughness is very good. The main varieties are: styrene copolymer of acrylonitrile (SAN), styrene maleic anhydride copolymer (SMA), styrene butadiene styrene copolymer (SBS), styrene and acrylic acid ester copolymer, and using them as a modification of the substrate. SAN high heat distortion temperature than transparent PS, its resistance to solvents also has improved, has excellent permeability. Rubber modified SAN acrylonitrile butadiene styrene copolymer (ABS) and acrylonitrile. Styrene acrylate copolymer (ASA) resin. The heat distortion temperature is higher than transparent PS S-MA, up to 40 ° f, it has an excellent transparency and gloss. SMA rubber-modified or glass fiber reinforced. SBS and SBS-modified to improve impact resistance, flexibility and liquidity components used in the production of sticky and bending resistance of products such as cement, asphalt felt soles, and SBS are also used to produce transparent impact PS. Styrene copolymer of acrylate elastomer with excellent physical properties of transparent impact PS.