EVA-g-MAH和改性纳米碳酸钙增韧PC/ABS合金的研究

Toughening of polycarbonate/acrylonitrile-butadiene-styrene(PC/ABS) blends by ethylenevinyl acetate-grafted maleic anhydride copolymer(EVA-g-MAH) and modified nano-CaCO_3

分别将醋酸乙烯酯-马来酸酐接枝共聚物(EVA-g-MAH)和改性纳米碳酸钙与聚碳酸酯(PC)、丙烯腈-丁二烯-苯乙烯共聚物(ABS)在双螺杆挤出机中共混,制备了PC/ABS复合材料。对复合材料力学性能研究表明,添加3份EVA-g-MAH增韧的合金的缺口冲击强度增加到最大值50.3 kJ/m2,增幅达43%。添加7份双单体聚合改性的纳米碳酸钙微粒将PC/ABS合金的缺口冲击强度增加到41.3 kJ/m2。主要以银纹化增韧的弹性体EVA-g-MAH的增韧效果优于改性纳米碳酸钙的剪切流动增韧效果,增韧过程均是将点应力分散为整个颗粒表面的面应力。改性纳米碳酸钙增韧弥补了弹性体增韧对合金拉伸强度降低的不足。

Ethylenevinyl acetate-grafted maleic anhydride copolymer （EVA-g-MAH） and surface modified nano- CaCO3 were melt blended with polycarbonate （PC） and acrylonitrile-butadiene-styrene （ABS） using a doublescrew extruder in order to prepare PC/ABS composite materials. Investigation of the mechanical properties showed significant improvement in the single-notched impact strength of PC/ABS blends could be obtained by the addition of 3 parts per hundred of EVA-g-MAH or 7 parts per hundred of nano-CaCO3 composite particles. The notch impact strength of the PC/ABS blends reached maximum values of 50.3 kJ/m^2 in the presence of EVA-g-MAH and 41.3 kJ/m^2 with added modified nano-CaCO3. Crazing in the case of EVA-g-MAH and shear yielding in the case of modified nano-CaCO3 are believed to be the main origins of the toughening effect, with toughening effect of the former being superior. The toughening mechanism involves delocalization of the part point tension over the whole surface. The tensile strength is also improved by filling with＇ modified nano-CaCO3 particles.