Acrylonitrile-butadiene-styrene base rubber

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. 

Other Impact-Modified Commercial Grafting-Based Polymers Typical HIPS and ABS polymers are opaque materials however, MABS (methyl methacrylate-acrylonitrile-butadiene-styrene) polymers, which are produced by processes similar to those used in the production of ABS, are transparent materials. This property is obtained by the addition of methyl methacrylate (MMA) to the recipe in order to impart transparency to the polymer by equalizing the refracting index of the rubber particles to that of the matrix. These materials find applications... 

Styrene serves as the monomer for the well-known polymer—polystyrene. It also serves as the source of many copolymers, that is polymers made from two monomers at varying compositions, such as SAN = styrene-acrylonitrile SBR = styrene-butadiene rubber (the major synthetic rubber) SBS = styrene-butadiene-styrene (a modem family of thermoplastic mbbers which are not cross-linked) and the well-known terpolymer ABS which is based on 3 monomers—acrylonitrile-butadiene-styrene. 

Many thermoplastics are heterogeneous (or heterophase) because they contain liquid or rubber dispersions that improve their physical properties with respect to those of the continuous brittle phase. Examples of this are the softening of PVC by the presence of phthalate droplets and the improved toughness of HIPS or the polymer of acrylonitrile-butadiene-styrene (ABS) by addition of PBD-based rubber particles. This chapter will focus on the (heterogeneous, bulk and free-radical) polymerizations leading to the production of HIPS and PVC. 

The rubber-modified aromatic polymeric materials, for example, high-impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS) are the least stable because of the rapid photooxidation of the rubber component, which sensitizes the polymer to further oxidation. Diene-based rubbers are also susceptible to degradation by ozone, which causes chain scission of the main-chain... 

Aspects of viscosity, elasticity, and morphology have been discussed in general terms by various workers [73-76]. Rheological studies specific to particular polymers include dynamic rheological measurements and capillary rheometry of rubbers [77], capillary rheometry of PP [78], degradation of PP [79], torsion rheometry of PE [80], viscosity effects in blends of PC with styrene-acrylonitrile and acrylonitrile-butadiene-styrene [81], peel adhesion of rubber-based adhesives [82], and the effect of composition of melamine-formaldehyde resins on rheological properties [83]. 

FTIR spectroscopy has been applied in the study of polymer blends including Neoprene rubber, chlorosulfonated PE, nitrile rubber, polyvinyl chloride (PVC) containing carbon black and other fillers [86], Nylon 6 inorganic [87], polyhydroxyether sulfone/poly(N-vinyl pyrrolidone) [88], graphite-based low-density polyethylene [89], caprolactone/Nafion blends [90], polybutylene terephthalate/polyamide [91], polyphenylene sulfide/acrylonitrile - butadiene - styrene [92], PMMA/polypyrrol [93], and lower or high performance liquid chromatography (LDPE/HDPE) [94]. 

Among the various plastic materials used for chrome-plated parts, ABS (copolymer of acrylonitrile-butadiene-styrene) and PC/ABS (blends of ABS with polycarbonate) are most common. Nearly 85% of the total plated plastic surface area is based on ABS or PC/ABS. The technology for etching out the rubber particles from the ABS phase using an oxidative mixture of sulfuric and chromic acid has been widely used in the industry for nearly 40 years. The etched surface is subsequently activated using precious metal species, which is then followed by an electroless deposition of a thin layer of nickel or copper. In this marmer, the smface of the otherwise non-conductive plastic is rendered electrically conductive. Subsequently, multiple layers of different... 

Novel styrenic-based TPEs based on blends of a thermoplastic (polystyrene or styrene acrylonitrile) with a rubber (styrene butadiene or ethylene vinylacetate), with special reference to compatibilization and dynamic vulcanization, were reported by Patel et al. The performance properties were correlated with the interaction parameter and the phase morphology of the blend components [62]. 

Sadhu, S. Bhowmick, A.K. Preparation and properties of nanocomposites based on acrylonitrile-butadiene rubber, styrene-butadiene rubber, and polybutadiene rubber. J. Polym. Sci. B Polym. Phys. 2004, 42 (9), 1573-1585. 

Early interest in acrylonitrile polymers was not based on its potential use in synthetic fibers. Instead, most interest in these polymers was for their use in synthetic rubber. In 1937, LG. Farbenindustrie introduced the first acrylonitrile-butadiene rubber. Synthetic rubber compounds based on acrylonitrile were developed in the United States during the early 1940s in response to wartime needs. American Cyanamid, however, was the sole U.S. producer of acrylonitrile at that time. In addition to acrylonitrile-butadiene rubber, polyblends of acrylonitrile-butadiene with acrylonitrile-styrene copolymers were developed by the United States Rubber Co. After the war, the demand for acrylonitrile dropped sharply, and American Cyanamid was still the sole U.S. producer. 

Poly(vinyl chloride) (PVC) homopolymer is a stiff, rather brittle plastic with a glass temperature of about 80°C. While somewhat more ductile than polystyrene homopolymer, it is still important to blend PVC with elastomer systems to improve toughness. For example, methyl methacrylate-butadiene-styrene (MBS) elastomers can impart impact resistance and also optical clarity (see Section 3.3). ABS resins (see Section 3.1.2) are also frequently employed for this purpose. Another of the more important mechanical blends of elastomeric with plastic resins is based on poly(vinyl chloride) as the plastic component, and random copolymers of butadiene and acrylonitrile (AN) as the elastomer (Matsuo, 1968). On incorporation of this elastomeric phase, PVC, which is ordinarily a stiff, brittle plastic, can be toughened greatly. A nonpolar homopolymer rubber such as polybutadiene (PB) is incompatible with the polar PVC. Indeed, electron microscopy shows... 

Acrylonitrile-butadiene rubber, NBR, styrene-aciylonitrile rubber, SAN, ethylene-vinyl acetate copolymer, EVA, and acrylic copolymers are helpful modifications of polyvinylchloride that change its processing characteristics and elastomeric properties. Blending with these copolymers helps to reduce the requirement for low molecular weight plasticizers. Ethylene-vinyl acetate copolymer plays a role of high molecular weight plasticizer in production of vinyl hose. This reduces the amount of DOP used in flexible hose applications. Ethylene copolymer is used plasticize PVC that reduces gel. "" Phthalate plasticizers can be eliminated from water based adhesives because of utilization of vinyl acetate ethylene copolymer as a high molecular plasticizer/modifier. " ... 

Rubber mixes, prepared with their application, were based on styrene-butadiene rubber (SBR) KER 1500 (Synthos S.A., Poland) and acrylonitrile-butadiene rubber (NBR) NT 1845 (Lanxess, Germany). 

The butadiene-acrylonitrile ratio in nitrile rubbers is less standardized than the butadiene-styrene ratio in SBR. Commercial rubbers usually contain 25-50% acrylonitrile with 34% being a common typical figure for a general purpose grade. Since acrylonitrile has a much lower molecular weight than styrene and is virtually the same as butadiene this means that in such a general purpose grade about one structural unit in three is based on acrylonitrile whereas in a standard SBR only about one unit in six is based on styrene. 

Water-based paints make use of an emulsion of a polymer composed of vinyl acetate, vinyl chloride, acrylics, acrylonitrile, ethylene, styrene, butadiene, and isoprene. The paint consists of an emulsion of polymer known as latex because their appearance is similar to rubber latex or sap from the rubber tree. The oil-in-water emulsion has plasticizers to smooth out the drying surface and to lower the glass transition temperature of the polymer to below room temperature. As drying occurs and water is lost, the polymer particles coalesce, forming a continuous impermeable film. 

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