ABS plastics

Some typical properties of styrene-acrylonitrile plastics, referred to in many countries as SAN, are compared with those of other styrene-based plastics in Table 16.7. 

The market for SAN has remained small relative to that for polystyrene and ABS (discussed in the next section) and is probably only about 5% that of the latter. Major producers are BASF, Dow, Monsanto and Montedison. 

The important features of rigidity and transparency make the material competitive with polystyrene, cellulose acetate and poly(methyl methacrylate) for a number of applications. In general the copolymer is cheaper than poly(methyl methacrylate) and cellulose acetate, tougher than poly(methyl methacrylate) and polystyrene and superior in chemical and most physical properties to polystyrene and cellulose acetate. It does not have such a high transparency or such food weathering properties as poly(methyl methacrylate). As a result of these considerations the styrene-acrylonitrile copolymers have found applications for dials, knobs and covers for domestic appliances, electrical equipment and car equipment, for picnic ware and housewares, and a number of other industrial and domestic applications with requirements somewhat more stringent than can be met by polystyrene. 

SAN is also used for pharmaceutical and cosmetic packaging. Usage breakdown for Western Europe in the early 1990s has been estimated at 28% for household products, 21% for domestic electrical applications, 8% for battery casings, 12% for pharmaceutical/cosmetic packaging and a large figure of 31% for other applications. 

Glass-reinforced grades of SAN exhibit a modulus several times that of the unfilled polymer and, as with other glass-filled polymers, a reduced coefficient of thermal expansion and lower moulding shrinkage. The materials are thus of interest on account of their high stiffness and dimensional stability. 

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ABS plastics A group of plastic materials based on blended copolymers of styrene-acrylo ... 

Styrene is manufactured by alkylating benzene with ethene followed by dehydrogenation, or from petroleum reformate coproduction with propylene oxide. Styrene is used almost exclusively for the manufacture of polymers, of which the most important are polystyrene, ABS plastics and styrene-butadiene rubber. U.S. production 1980 3 megatonnes. 

ABS is the sixth largest volume thermoplastic resin and the principal engineering (stmctural or load bearing) plastic (89). ABS is a terpolymer manufactured by copolymerizing acrylonitrile and styrene in the presence of polybutadiene mbber. Important producers of ABS plastics include General Electric, Monsanto (Lustran), and Dow (Abtec) (see Acrylonitrile polymers). 

ABS plastic, a polymer consisting of polybutadiene spheroids is dispersed in a continuous phase of poly(styrene—acrylonitrile). The chromic acid attacks the polybutadiene at a much higher rate than the continuous phase. This gives an excellent microroughened surface with superior metal-to-plastic bond strength. A typical recommended formulation consists of 20 vol % sulfuric acid, 420 g/L chromic acid, and 0.1—1.0% of a fluorocarbon wetting agent. The plastic is treated with this formulation for 6—10 min at 60—65°C. 

Neutralizing removes the large amount of hexavalent chromium from the surface of the part. Hexavalent chromium shortens the life of the catalyst, and trace amounts completely inhibit electroless nickel deposition. The neutralizer is usually a mildly acidic or basic reducing agent, but other types of neutralizers are available, especially for substrates that are difficult to plate. The neutralizer may also contain surfactants (qv) or other compounds that increase catalyst absorption absorption promoters are often needed for non-ABS plastics. 

The processing behaviour of ABS plastics is largely predictable from their chemical nature, in particular their amorphous nature and the somewhat unpleasant degradation products. The main points to bear in mind are ... 

In order to simplify the analytical exercise, a particular material was selected for each. The single curved sheet is made of TS polyester fiber glass molded to the shape. The corner supported pan is molded from ABS plastics. The structural foam unit is molded from PP with glass fiber filler. 

Fig. 8-24 Izod impact strength of ABS plastic vs. stock (melt) temperature.

When polymerization proceeds in the presence of modifiers, the mechanochemical process enhances cross-linking and, correspondingly, improves the physicochemical properties of final plastics. For example, mechanochemical treatment of acrylonitrile butadiene styrene (ABS) plastic in the presence of tolnene diisocyanate improves thermal oxidative stability of the plastic (Chetverikov et al. 2002). 

Styrene-butadiene block polymers also find applications in blends with polystyrene and ABS plastics. When minor amounts of rubbery SBS or (SB)n- X block polymers are blended with high molecular weight polystyrene such that the polystyrene forms the... 

Kutcher, R.J. (1978) Occupational Exposure to Acrylonitrile in the Manufacture of ABS Plastics, Masters thesis. Chapel Hill, NC, University of North Carolina... 

D. Li and C.-L. Yang, Acidic electroless copper deposition on aluminum-seeded ABS plastics, Surf. Coat. Technol., 203(23) 3559-3568, August 2009. 

B.J. Jody, B. Arman, D.E. Karvelas, J.A. Pomykala, Jr., and E.J. Daniels, Method for the separation of high impact polystyrene (HIPS) and acrylonitrile butadiene styrene (ABS) plastics, US Patent 5 653867, assigned to The University of Chicago (Chicago, IL), August 5,1997. 

N. Miskolczi, W.J. Hall, A. Angyal, L. Bartha, and P.T. Williams, Production of oil with low organobromine content from the pyrolysis of flame retarded HIPS and ABS plastics, /. Anal. Appl. Pyrolysis, 83(1) 115-123, September 2008. 

Today let us consider four case studies involving market development activity. The first of these is the application of an ABS plastic in the shape of a thermoformed sheet to create the entire structure of a camper unit mounted on the back of a pickup truck. Less than three years ago, William Suiter, then President of Marbon Chemical, and representatives of Ford Motor Company agreed that a... 

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