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ABS Resins

المؤلف:  A. Ravve

المصدر:  Principles of Polymer Chemistry

الجزء والصفحة:  371

2026-02-02

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ABS Resins

Styrene–acrylonitrile copolymers are produced commercially for use as structural plastics. The typical acrylonitrile content in such resins is between 20 and 30%. These materials have better solvent and oil resistance than polystyrene and a higher softening point. In addition, they exhibit better resistance to cracking and crazing and an enhanced impact strength. Although the acrylonitrile copolymers have enhanced properties over polystyrene, they are still inadequate for many applications. Acrylonitrile–butadiene–styrene polymers, known as ABS resins, were therefore developed. Although ABS resins can potentially be produced in a variety of ways, there are only two main processes. In one of them acrylonitrile–styrene copolymer is blended with a butadiene–acrylonitrile rubber. In the other one, interpolymers are formed of polybutadiene with styrene and acrylonitrile. In the first one, the two materials are blended on a rubber mill or in an internal mixer. Blending of the two materials can also be achieved by combining emulsion latexes of the two materials together and then coagulating the mixture. Peroxide must be added to the blends in order to achieve some cross-linking of the elastomer to attain optimum properties. A wide range of blends are made by this technique with various properties [201]. Most common commercial blends of ABS resins may contain 70 parts of styrene–acrylonitrile copolymer (70/30) and 40 parts of butadiene–nitrile rubber (65/35). In the second process, styrene and acrylonitrile are copolymerized in the presence of polybutadiene latex. The product is a mixture of butadiene homopolymer and a graft copolymer.