Acrylonitrile-butadiene-styrene physical

Analytical investigations may be undertaken to identify the presence of an ABS polymer, characterize the polymer, or identify nonpolymeric ingredients. Fourier transform infrared (ftir) spectroscopy is the method of choice to identify the presence of an ABS polymer and determine the acrylonitrile—butadiene—styrene ratio of the composite polymer (89,90). Confirmation of the presence of mbber domains is achieved by electron microscopy. Comparison with available physical property data serves to increase confidence in the identification or indicate the presence of unexpected stmctural features. Identification of ABS via pyrolysis gas chromatography (91) and dsc ((92) has also been reported. 

Another widely used copolymer is high impact polystyrene (PS-HI), which is formed by grafting polystyrene to polybutadiene. Again, if styrene and butadiene are randomly copolymerized, the resulting material is an elastomer called styrene-butadiene-rubber (SBR). Another classic example of copolymerization is the terpolymer acrylonitrile-butadiene-styrene (ABS). Polymer blends belong to another family of polymeric materials which are made by mixing or blending two or more polymers to enhance the physical properties of each individual component. Common polymer blends include PP-PC, PVC-ABS, PE-PTFE and PC-ABS. 

The most common advanced composites are made of thermosetting resins, such as epoxy polymers (the most popular singlematrix material), polyesters, vinyl esters, polyurethanes, polyimids, cianamids, bismaleimides, silicones, and melamine. Some of the most widely used thermoplastic polymers are polyvinyl chloride (PVC), PPE (poly[phenylene ether]), polypropylene, PEEK (poly [etheretherketone]), and ABS (acrylonitrile-butadiene-styrene). The precise matrix selected for any given product depends primarily on the physical properties desired for that product. Each type of resin has its own characteristic thermal properties (such as melting point... 

Acrylonitrile-Butadiene-Styrene (ABS). ABS plastics are derived from acrylonitrile, butadiene, and styrene. ABS materials have a good balance of physical properties. There are many ABS modifications and many blends of ABS with other thermoplastics that can affect adhesion properties. ABS resin can be bonded to itself and to other materials with adhesives, by solvent cementing, or by thermal welding. 

Incorporation of Ti02 into polystyrene(s), styrene-acrylonitrile, acrylonitrile-butadiene-styrene, and other associated copolymers and alloys is normally by way of concentrates prepared on equipment similar to that used for polyethylene. This concentration step is usually necessary to achieve high-quality dis-persion so color properties are fully developed and physical properties are not compromised. 

Acrylonitrile/Butadiene/Styrene (ABS) Acry-lonitrile/butadiene/styrene (ABS) polymers are not true terpolymers. As HIPS they are multipolymer composite materials, also called polyblends. Continuous ABS is made by the copolymerization of styrene and acrylonitrile (SAN) in the presence of dissolved PB rubber. It is common to make further physical blends of ABS with different amounts of SAN copolymers to tailor product properties. Similar to the bulk continuous HIPS process, in the ABS process, high di-PB (>50%, >85% 1,4-addition) is dissolved in styrene monomer, or in the process solvent, and fed continuously to a CSTR where streams of AN monomer, recycled S/AN blends from the evaporator and separation stages, peroxide or azo initiators, antioxidants and additives are continuously metered according to the required mass balance to keep the copolymer composition constant over time at steady state. 

Impact modifiers are added primarily to PVC, polyethylene, polypropylene, polyamides and polyesters. They absorb the energy generated by impact and dissipate it in a non-destructive way. Impact modifiers are physically rubbery and semi-compatible with the polymer. The mechanism of absorbing impact in polymers is not fuUy understood, but these additives increase the tensile strength of the material. The impact modifiers most commonly used include acrylonitrile-butadiene-styrene (ABS) polymers, acrylics and ethylene-vinyl acetate (Carraher, 2000). ABS generates opacity or stress-whitening when used as... 

Acrylonitrile-butadiene-styrene (ABS) copolymers are produced by three monomers acrylonitrile, butadiene, and styrene. The desired physical and chemical properties of ABS polymers with a wide range of functional characteristics can be controlled by changing the ratio of these monomers. They are resistant... 

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. 

Blending two or more polymers offers yet another method of tailoring resins to a specific application. Because blends are only physical mixtures, the resulting polymer usually has physical and mechanical properties that lie somewhere between the values of its constiment materials. For instance, an automotive bumper made from a blend of PC resin and thermoplastic polyurethane elastomer gains rigidity from the PC resin and retains most of the flexibility and paintability of the polyurethane elastomer. For business machine housings, a blend of PC and ABS (acrylonitrile—butadiene—styrene copolymer) resins offers the enhanced performance of PC flame retar-dance and ultraviolet (UV) stability at a lower cost. 

Acrylonitrile-butadiene-styrene (ABS) is one of the most frequently used polymers in the production of electrical and electronic equipment, it also has widespread applications in automobiles, communication instruments and other commodities. Within the electrical and electronic sector, the quantity of recycled plastics could be increased via the recycling of ABS to reduce environmental, economic and energy issues. Table 2.5 illustrates some of the physical parameters of ABS. 

Eguiazabal, J. L, and Nazabal, J. (1990) Reprocessing polycarbonate/acrylonitrile-butadiene-styrene blends influence on physical properties, Polym. Eng. Sci. 30, 527-531. 

Wyzgoski, M. G. (1980). Physical Aging of Poly(acrylonitrile-butadiene-styrene). II. Defferential Scanning Calorimetry Measurements. J. Appl. Polymer Sci., 25(7), 1455-1467. 

Tang, J.K.Y. and Lee-Sullivan, P. (2008) Observation of physical aging in a polycarbonate and acrylonitrile-butadiene-styrene blend. J. Appl. Pdlym. Set.. 110, 97. 

The term ABS was originally used as a general term to describe various blends and copolymers containing acrylonitrile, butadiene and styrene. Prominent among the earliest materials were physical blends of acrylonitrile-styrene copolymers (SAN) (which are glassy) and acrylonitrile-butadiene copolymers (which are rubbery). Such materials are now obsolete but are referred to briefly below, as Type 1 materials, since they do illustrate some basic principles. Today the term ABS usually refers to a product consisting of discrete cross-linked polybutadiene rubber particles that are grafted with SAN and embedded in a SAN matrix. 

The polymers described above have been chemically pure, although physically helerodisperse. It is oflen possible lo combine two or more of these monomers in the same molecule to form a copolymer. This process produces still further modification of molecular properties and, in turn, modification of the physical properties of file product. Many commercial polymers are copolymers because of the blending of properties achieved in this way. For example, one of the important new polymers of the past ten years has been the family of copolymers of acrylonitrile, butadiene and styrene, commonly called ABS resins. The production of these materials has grown rapidly in a short period of time because of their combination of dimensional stability and high impact resistance. These properties are related to the impact resistance of acrylonitrile-butadiene rubber and the dimensional stability of polystyrene, which are joined in the same molecule. 

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