Study On Modification Of PC/ABS Alloys

PC(polycarbonate)/ABS(acrylonitrile/butadiene/styrene) alloy is an important engineering thermoplastics, distinguished by its versatile combination of good mechanical properties. PC/ABS is one of the host polymers commonly used in the cover of the portable consumer electronic devices. Because PC/ABS is a multiphase blend requiring some compatibilization to obtain useful properties, however, the relatively limited interaction between PC and ABS apparently makes it impossible in this case to produce commercially useful materials without any compatibilizer. Thus, a modified scheme that deals with the blend morphology development of compatibilized PC/ABS blends and the mechanical properties of these materials. It would be useful and perhaps would expand the commercial opportunities for PC/ABS alloys.ABS-g-MAH was melting blended with polycarbonate (PC) and acrylonitrile/butadiene/styrene compolymer (ABS) using a double-screw extruder to obtain PC/ABS composite materials. The investigations of the mechanical properties showed that the notched impact strength was improved from 32.18 KJ/m² to 41.92KJ/m² and the tensile strength reached 53.05MPa, which raised by 3.61%. ABS-g-MAH can improve the compatibility and tougheness of PC/ABS alloy.PC/ABS/EVA composite material was prepared by EVA blending with PC and ABS. The investigations of the mechanical properties showed the single-notched impact strength of PC/ABS alloys by adding 5 shares of elastomer was markedly improved. When the elastic-core was 0.2-0.4μm and the elastomer dispersed uniformly in the resin blend the notched impact strength reached the highest value of 48.4 KJ/m², which increased by 50.3%. EVA dispersed in the resin, absorbed and dispersed impact stress by its shape changing to toughen PC/ABS alloys with crazing.EVA-g-MAH was melting blended with polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) to get the PC/ABS/elastomer composite materials. The investigations of the mechanical properties showed a markedly improvement on the single-notched impact strength of PC/ABS blends by adding elastomer. The notched impact strength of PC/ABS blends reached the maximum value of 50.3KJ/m² which rised by 56.31% by addition 3 shares of EVA-g-MAH. SEM micrographs of the fractured surface of PC/ABS blends revealed that the elastic-core was less than 0.4μm and dispersed uniformly in the resin blend, and the compatibilizing was improved. EVA in the EVA-g-MAH dispersed in resin, absorbed and dispersed impact tension by its shape changing to toughen the PC/ABS blends with crazing and compatibilizing of MAH. The torque of PC/ABS blend was improved by adding elastomer. There is no toughening effect by Nano-calcium carbonate (CaCO₃) filling in PC/ABS. Nano-calcium carbonate/polymer composite particles were prepared by soapless emulsion polymerization of methylmethacrylate (PMMA) and butyl acrylate (BA) on the surface of nano-CaCO₃ in nano-CaCO₃ aqueous suspension. The effects of composite particles on the mechanical properties of PC/ABS blends through twice extruding in double extruders were studied. The results showed that the single-notched impact strength of PC/ABS blends was improved from 32.18 KJ/m² to 41.3KJ/m² when 7 amount of composite particle was added, and the tensile strength was improved by filling 2 shares of modified nano-CaCO₃ particles. Nano-CaCO₃ composite particles have double toughening effects of inorganic nano-particles and elastomers. Shear yielding of modified nano-CaCO₃ could be the mainly toughening contribution. The toughening mechanism was that the nano-CaCO₃ particle delocalizes the part point tension over the whole surface. The dispersion degree of CaCO₃ particles in the blends was improved when filling the composite particles. The adding amount of the Nano-CaCO₃ composite particles is low, and the cost is acceptable, offering a good choice of the modification of PC/ABS alloy.