Properties and applications of ABS plastics

Several classes of ABS which show the above general characteristics but with specific attributes are recognised. One supplier for example classifies ABS materials into the following categories  

Over the years there has been some difference in the balance of use between UPVC and ABS in the United States compared with Western Europe. This was due largely to the earlier development in Western Europe of UPVC and in the United States of ABS. Thus, for example, whilst ABS consolidated its use for pipes and fittings in the United States, UPVC was finding similar uses in Europe. Whilst some of these traditional differences remain, ABS is now well established in both Europe and the United States. 

The commercial success of ABS polymers has led to the investigation of many other polyblend materials. In some cases properties are exhibited which are superior to those of ABS and some of the materials are commercially available. For example, the opacity of ABS has led to the development of blends in which the glassy phase is modified to give transparent polymers whilst the limited light aging has been countered by the use of rubbers other than polybutadiene. 

Notable among the alternative materials are the MBS polymers, in which methyl methacrylate and styrene are grafted on to the polybutadiene backbone. This has resulted in two clear-cut advantages over ABS. The polymers could be made with high clarity and they had better resistance to discolouration in the presence of ultraviolet light. Disadvantages of MBS systems are that they have lower tensile strength and heat deflection temperature under load. 

Besides the MBS materials, related terpolymers have been prepared. These include materials prepared by terpolymerising methyl methacrylate, acrylonitrile and styrene in the presence of polybutadiene (Toyolac, Hamano 500) methyl methacrylate, acrylonitrile and styrene in the presence of a butadiene-methyl methacrylate copolymer (XT Resin), and methylacrylate, styrene and acrylonitrile on to a butadiene-styrene copolymer. 

---

Acrylonitrile-Butadiene-Styrene (ABS) Terpolymer. The acrylonitrile and styrene copolymer is grafted onto polybutadiene. The properties of SAN are combined with a greatly improved impact resistance and heat distortion resistance. ABS terpolymers And application as engineering plastics, in household appliances, luggage, telephone housings, automotive parts, and many more. 

The development of new polymer alloys has caused a lot of excitement in recent years but in fact the concept has been around for a long time. Indeed one of the major commercial successes of today, ABS, is in fact an alloy of acrylonitrile, butadiene and styrene. The principle of alloying plastics is similar to that of alloying metals - to achieve in one material the advantages possessed by several others. The recent increased interest and activity in the field of polymer alloys has occurred as a result of several new factors. One is the development of more sophisticated techniques for combining plastics which were previously considered to be incompatible. Another is the keen competition for a share of new market areas such as automobile bumpers, body panels etc. These applications call for combinations of properties not previously available in a single plastic and it has been found that it is less expensive to combine existing plastics than to develop a new monomer on which to base the new plastic. 

Acrylonitrile-butadiene-styrene (ABS). ABS materials have superior strength, stiffness and toughness properties to many plastics and so they are often considered in the category of engineering plastics. They compare favourably with nylon and acetal in many applications and are generally less expensive. However, they are susceptible to chemical attack by chlorinated solvents, esters, ketones, acids and alkalis. 

Consistency, working time, setting time and hardening of an AB cement can be assessed only imperfectly in the laboratory. These properties are important to the clinician but are very difficult to define in terms of laboratory tests. The consistency or workability of a cement paste relates to internal forces of cohesion, represented by the yield stress, rather than to viscosity, since cements behave as plastic bodies and not as Newtonian liquids. The optimum stiffness or consistency required of a cement paste depends upon its application. 

ABS (30% acrylonitrile, 20% butadiene, and 50% styrene) is a tough plastic with outstanding mechanical properties ABS is one of the few plastics that combines both toughness and hardness. So the applications include ballpoint pen shells, fishing boxes, extruded pipes, and space vehicle mechanical parts. There s more than 20 pounds of ABS molded parts in an automobile. 

A property of great importance in applications for various carbon blacks in plastics, impact strength will be illustrated with ABS. The physical properties of ABS compounds are extremely sensitive to both quality of dispersion and aging. In this case, as indicated by Figure 11.11, precolored compounds show unproved dispersion over salt and pepper blends mixed in the holding machine. Better dispersion yields better impact retention. 

Acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acry- late (ASA) are rubber-toughened plastics based upon the styrene-acrylonitrile (SAN) copolymer matrix. The combination of the stiffness and toughness exhibited by these materials has made them increasingly attractive in engineering applications, and the activity of the patent literature testifies to a continuing interest in improving properties through modifications of structure. The aim of this paper is to discuss a quantitative approach to structure-property relationships in ABS and ASA polymers. 

The products based on thermoplastic starch and EVOH show mechanical properties suitable to meet the needs of specific industrial applications [99]. Their mouldability in traditional processing technologies is comparable with that of traditional plastics such as PS, ABS and LDPE [95]. The main limitation of these materials is the high sensitivity to low humidity, with consequent embrittlement. 

Compatibilisers make two largely incompatible polymers mix together to form a new blend or alloy. There has been a steep rise in demand for them in recent years, because polymer blends provide a fruitful way to tailor polymer properties to specific applications. They have also led to improved impact modifiers which, being polymeric, must form a blend whenever they are used. Some of the newer alloys, such as Rhodia s PA/ABS and Crompton s PP/SEBS, are highly impact-resistant. Compatibilisers are also used to improve the properties of mixed plastics waste and to compatibilise polymers with wood or mineral fillers. 

As one of such heat-resistant polymers, heat-resistant ABS is a plastic having excellent processability and mechanical properties, and it is the product that can particularly be applied to the field requiring high heat resistance among the applications where coloring properties and gloss are demanded. As the major use, it is broadly applied to electric and electronic products and daily miscellaneous goods further, it can be extensively applied to the interior and exterior materials of automobiles. 

---