Research On The Compatiblizing Modification Of PC/ABS Blend

PC/ABS blend is a kind of engineering plastics which has excellent properties. The blendwhich can make up the shortcomings of single material in properties is blended bypolycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS). The blend not only hasexcellent properties, but also has good low-temperature impact performance, high thermaldeformation temperature and light stability. Compared with PC, the PC/ABS blend not onlyhas lower melt viscosity, good processability and higher impact strength, but also decreasesthe sensibility about product to stress and cost. Compared with ABS, the heat deformationtemperature and mechanical property of PC/ABS are improved. The compatilizer needs to beadded to improve the compatibility, because the compatibility is poor and the solubilityparameter is different largely between the PC and PB (polybutadiene) which is the content ofABS. In this paper the MBS, ABS-g-MAH and MABS were employed as compatilizer toprepare PC/ABS blend. The scanning electron microscope (SEM), dynamicthermomechanical analysis apparatus (DMA) and capillary rheometer were applied toresearch the morphological structure, glass-transition temperature and rheological behavior ofPC/ABS blend.The mechanical property morphological structure states: firstly the proportion ofPC/ABS which was 70/30 was determined, and then the compatilizer MBS, ABS-g-MAH andMABS were added into the blend respectively. The notch impact strength and elongation atbreak of PC/ABS increased firstly and then decreased, tensile strength declined overall. It canbe seen from the morphological structure of the blend, the domain size of ABS phasedecreased obviously and distributed well, the compatilizer improved the cohesive forcebetween PC and ABS phase when the compatilizer MBS and MABS were added into theblend, so the compatibility of the blend was improved. With the increasement of compatilizerMBS and MABS, the glass transition temperature between PC and ABS closed to each other and the compatibility of the blend improved largely, which can be seed from the DMAanalysis.The rheological behavior of the PC/ABS blend was investigated. The results show:PC/ABS blend exhibited the characteristics of pseudoplastic fluid and presented thephenomenon of shear-thinning. The non-Newtonian index was 0.6～0.9 and thecharacteristics of pseudoplastic fluid did not alter with the addition of compatilizer MABSunder different temperature. At the given shear stress and shear rate, with the increasement ofcompatilizer MABS, the apparent viscosity of fusant increased firstly and then decreased;when the content of compatilizer MABS was 15 wt.%, the apparent viscosity obtainedmaximum. For the given shear stress, the activation energy for viscous-fluid of PC/ABS blenddecreased overall with the increasing addition of compatilizer MABS, so the temperature hadlittle effect on the melt flow.The innovation is that a simple and efficient bulk polymerization was employed tosynthesize a new kind of reactive compatilizer MABS, which was used to improve thecompatibility of the PC/ABS blend. It not only improved the mechanical properties of theblends, but also decreased the dasage and reduced the cost, which supplied a better approachto improve the properties of PC/ABS blend.