Polycarbonate ABS blends

Usage of phosphoms-based flame retardants for 1994 in the United States has been projected to be 150 million (168). The largest volume use maybe in plasticized vinyl. Other use areas for phosphoms flame retardants are flexible urethane foams, polyester resins and other thermoset resins, adhesives, textiles, polycarbonate—ABS blends, and some other thermoplastics. Development efforts are well advanced to find appHcations for phosphoms flame retardants, especially ammonium polyphosphate combinations, in polyolefins, and red phosphoms in nylons. Interest is strong in finding phosphoms-based alternatives to those halogen-containing systems which have encountered environmental opposition, especially in Europe. 

Alloys and blends are of great commercial significance. The archetype of "alloys" is the poly(phenylene oxide)—polystyrene resin discussed eadier. Important examples of blends based on immiscible resins are afforded by the polycarbonate—poly(butylene terephthalate) resins and polycarbonate—ABS blends. 

Polycarbonate-ABS blends, 19 824-825 Polycarbonate blends, 20 361-362 Polycarbonate-polyester blends, 19 824, 825 Polycarbonate resin(s)... 

M. Zobel, T. Eckel, T. Derr, and D. Wittmann, Flame-resistant polycarbonate ABS blends, US Patent 6528561, assigned to Bayer Aktiengesellschaft (Leverkusen, DE), March 4, 2003. 

Fig. 3. Dependence of Izod impact strength on temperature for (-) polycarbonate, (—) ABS, and (-) polycarbonate-ABS blends. To convert J to cal,...

Fundamental studies of blends of polycarbonate with aciyloni-trile-buladiene-styrene (ABS) indicate that the presence of ABS greatly decreases the melt viscosity in the blend, enhancing processibility. A synergistic improvement of the notched impact strength at low temperature is also seen for polycarbonate-ABS blends. 

Filled conductive polymers used for packaging include polycarbonate, polyolefin, and styrenics incorporating fillers such as carbon, aluminum, and steel flakes and fibers. A polycarbonate/ABS blend (Bayblend ME) introduced by Bayer is 4% aluminum filled and suited to many screening functions. 

Mobay has introduced a 40% aluminum flake-filled, flame-retardant grade polycarbonate/ABS blend that is molded into internal cover configurations for EMI shielding. 

Bayer has marketed flame retardant polycarbonate/ABS blends under the Bayblend name. They contain nanofillers for use in thin-walled products, including housings for mobile phones and palmtop devices. This means that a halogen-free plastics insulating material can meet UL-94 V-0 specifications. It is possible to optimise the formulation either for high melt flow characteristics or for high melt strength. 

TPUs and polycarbonate blends and TPU/polycarbonate/ABS blends are used with the addition of the polycarbonate giving higher modulus and solvent stress cracking resistance as well as making processing of the TPU much easier. TPU/polycarbonate/polybutylene terephthalate blends are superior to their ABS analogue for resistance to environmental stresscracking resistance. 

Bayblend, Polycarbonate/ABS blends, Bayer Corp., Polymers Div. 

Polycarbonate/ABS blends are used as a lower-cost, slightly lower-performing option in very price-sensitive segments where thermal requirements are somewhat lower than those of standard polycarbonate. Two basic formulations of PC/ABS blends are generally used flame-retardant (FR) and non-flame-retardant grades. 

Tetraphenyl Bisphenol-A Diphosphate [5945-33-5], This is the main component of an oligomer, Akzo Nobel s FYROLFLEX BDP, Great Lakes REOFOS BAPP, or Albemarle s NCendX P30, and is used for the same applications as the RDP discussed above. RDP and BDP are mainly the diphosphates with small amounts of the higher oligomers. Although BDP has a lower percentage of phosphorus (9%) than RDP (11%), it is lower in cost, and has a substantial hydrolytic stability advantage (108), a factor of particular importance for the apphcation in polycarbonate-ABS blends. 

Makroblend . Polycarbonate/ABS blend. Injection molding guidelines. Miles Inc. 1992. 

One apparent exception is triphenyl phosphate which, although having a low melting point of 50°C, is stable enough to be processed into engineering thermoplastics such as polycarbonate/ABS blends. A vapour phase action is assumed as it boils undecomposed at 370 C. 

Parts are often manufactured using many different plastics (e.g., polypropylene housing and nylon gears) or else plastic blends (e.g., polycarbonate/ ABS blends). Recychng parts made from mixed plastics remains chemically complex because of the general lack of compafibihty. A review article [85] highlighted how new materials advance parts production and that the majority of the new materials identified were blends. 

Both random and block copolymers of polycarbonate have been made. Copolymers with terephthalic and isophthalic acid units are used in glazing applications. Polymerization with mono- or difunctional poly (dimethylene) oxide gives, respectively, ABA and (AB) block copolymers with improved heat distortion temperature. Blends with ABS exhibit good toughness and electrical properties. Polycarbonate-ABS blends are used for dashboard panels, spoilers, wheel caps, housings for lamps, and office equipment. 

Inberg JPF, Gaymans RJ. Co-continuous polycarbonate/ABS blends. Polymer 2002 43 2425-34. 

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