SMA boosts thermal performance of ABS

21-Nov-11

Because XIRAN® SMA has a high glass transition temperature, it is able to significantly boost performance and value of various virgin and recycled resins, particularly acrylonitrile butadiene styrene (ABS) and polymethyl methacrylate (PMMA). Available in a broad range of molecular weights and maleic anhydride (MA) contents, XIRAN® can improve thermal stability to widen the application window, make parts easier to bond, paint or print on at a cost significantly below that of several other additives and proprietary polymer modification techniques. The material can also act as excellent compatibilizer between resins that are normally immiscible, such as PA/ABS. In a recent benchmark analysis of heat boosters, Polyscope Polymers has highlighted the benefits that can be obtained by the use of readily available XIRAN® SMA copolymers as a modifier in thermoplastic polymers. According to Patrick Muezers, Managing Director of Polyscope, SMA is a unique polymer: “Styrene maleic anhydride has long been established as a high performance thermoplastic in its own right. Increasingly, it is now being used as a functional additive and compatibilizer in other amorphous and to some extent crystalline thermoplastics.” Polyscope has the industry’s broadest offering of SMA additives. Grades vary in molecular weight and maleic anhydride content, both of which have important effects on host polymer properties. XIRAN SMA’s high glass-transition temperature (Tg) range of 145-175°C makes it a very cost-effective means of boosting high temperature performance in PMMA and ABS resins. Dimensional stability is also improved. The addition of between 1.5 and 3.3% SMA typically raises Vicat softening point by around 1°C. Compounders and recyclers can take lower value, standard- or scrap-grade ABS and transform it into value-added high-heat ABS using SMA resin, which is less costly and far more accessible than many other additives like N-phenyl maleimide (NPI) and alpha-methyl styrene acrylonitrile (AMSAN). In ABS, SMA can yield Vicat B values of 85-120°C.