Acrylonitrile-butadiene-styrene commercially available

The most important commercial blends of BPA-PC are poly(acrylonitrile-butadiene-styrene) (PC/ABS) and polybutylene terephthalate (PC/PBT) or polyethylene terephthalate (PET). Commercial grades of PC/ABS include CYCOLOY (GE), Bayblend (Bayer), and PULSE (Dow). PC/ABS blends exhibit improved flow and processability and enhanced low-temperature impact strength in comparison to PC (Fig. 3). These blends are widely used in applications requiring enhanced impact resistance, such as interior automotive parts and computer and electronics applications such as computer housings and cell phones. Non-halogenated flame-retardant PC/ABS blends are widely available. Poly(acrylic-styrene-acrylonitrile) (PC/ ASA) blends (GELOY , GE Luran , BASF) provide improved weatherability for outdoor applications such as exterior automotive parts, but exhibit reduced impact performance at low temperatures in comparison to PC/ABS. PC/PBT or PET blends (XENOY , GE Makroblend , Bayer) provide enhanced chemical resistance and weatherability for applications such as lawn and garden equipment and automotive bumpers and fasdas. 

Commercially important examples of rubber-toughened plastics include the high-impact polystyrenes (HIPS), in which polystyrene is toughened with a polybutadiene mbber, and the acrylonitrile-butadiene-styrene (ABS) plastics, in which a polybutadiene or poly(butadiene-co-acrylonitrile) rubber toughens a poly(styrene-co-acrylonitrile) glassy phase. More complete discussions of these two-phase polymer systems are available elsewhere [7,8]. 

Synthetic. The main types of elastomeric polymers commercially available in latex form from emulsion polymerization are butadiene—styrene, butadiene—acrylonitrile, and chloroprene (neoprene). There are also a number of specialty latices that contain polymers that are basically variations of the above polymers, eg, those to which a third monomer has been added to provide a polymer that performs a specific function. The most important of these are products that contain either a basic, eg, vinylpyridine, or an acidic monomer, eg, methacrylic acid. These latices are specifically designed for tire cord solutioning, papercoating, and carpet back-sizing. 

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. 

Copolymerization of butadiene with acrylonitrile is, like that of styrene, also carried out in emulsion. This may be a discontinuous copolymerization by the cascade process or it may be continuous with withdrawal of the latex from the bottom of the reaction pot. Acrylonitrile and butadiene are used in the azeotropic ratio of 37 63. The copolymers are commercially available under the name of nitrile rubber, or the initials NBR, previously also Buna N or GR-N. They are oil-resistant elastomers. Latices produced with cation-active emulsifiers are used to coat or impregnate textiles and paper. 

Many applications are being found for synthetic rubbers, which are synthetic polymers possessing rubber-like properties. Among those available commercially are butadiene-styrene and butadiene-acrylonitrile (called Buna rubbers), polyisoprene, and polybutadiene. Their properties may be modified considerably more than vulcanized rubbers, particularly with respect to resistance to oxidizing agents, solvents, and oils. Their adhesion to metals, however, is generally poorer. 

Although the impact strength of acrylonitrile-styrene copolymers is higher than that of polystyrene, it is still sufficiently low to make it a limiting factor in many applications. Understandably, therefore, the addition of rubbery materials to acrylonitrile-styrene copolymers has been extensively investigated and as a result materials based on acrylonitrile, butadiene and styrene have become commercially available. Such materials are commonly referred to as ABS polymers. It should be noted that commercial ABS polymers are not random terpolymers of acrylonitrile, butadiene and styrene. 

Homopolymers of polybutadiene can consist of three basic isomeric forms (czs-1,4, trans-1,4, and 1,2 vinyl), and these can be present in different sequential order. Copolymers may obtain a variety of co-monomers, such as styrene, acrylonitrile, etc. Depending on their distribution in the chain, random copolymers or block copolymers of different types and perfection can be produced. There are many synthetic elastomers based on butadiene available commercially. 

In spite of its availability and the clarity of this brittle polymer, styrene monomer remained a laboratory curiosity for over a century. However, after Tschunker produced styrene-butadiene elastomeric copolymers (Buna-S), chemists at IG Farbenindustrie reinvestigated styrene homopoljrmers and several copolymers including st3n-ene-co-acrylonitrile. Polystyrene was produced commercially in Germany in 1925. 

While there are commercial uses for pure Buna rubber, a more successful substance was created as a copolymer of butadiene and styrene (Buna-S). Another successful copolymer includes acrylonitrile (perbunan). Both products were widely available in Germany at the time of the writing of Meyer s monograph. 

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