【作者】 查留锋；

【导师】 毋伟；

【作者基本信息】 北京化工大学 ， 化学工程， 2007， 硕士

【摘要】 PC／ABS合金是一种性能优良的复合材料，被广泛应用于电子电器外壳件。由于手机类电器外壳趋向于超薄、超轻，其所用PC／ABS合金材料要求具有良好的力学性能和较高的性价比。然而PC、ABS有限的相容性，影响了PC／ABS共混材料的力学性能，改善PC／ABS复合体系中微团间相容性有利于提高复合材料的整体力学性能。ABS-g-MAH与PC、ABS经双螺杆挤出机反应共混，制备了PC／ABS复合材料。力学性能测试显示复合材料的缺口冲击强度由32.18KJ／m²增强到41.92KJ／m²；拉伸强度达到53.05MPa，增幅为3.61％。力学性能提高表明马来酸酐接枝ABS提高了PC／ABS共混体系的相容性。适量相容剂的作用不仪使复合材料的韧性得到提高，同时增强了材料的拉伸性能。EVA与PC、ABS共混制备了PC／ABS／弹性体复合材料。对复合材料力学性能研究表明，添加5份弹性体EVA显著增加了PC／ABS合金的抗冲击性能，合金的缺口冲击强度提高到48.4KJ／m²，增幅达50.4％。经共混EVA在PC／ABS合金中形成了粒径为0.2～0.4μm的弹性核，且弹性核在树脂基体中分散均匀，大小均一。分散在树脂中的EVA主要以银纹化增韧基体树脂，即通过自身构象改变来吸收和分散冲击能量，将受到的点应力分散为整个弹性球表而的面应力，引起合金中微观区域大面积微开裂，从而提高了PC／ABS合金的抗冲击性能。EVA-g-MAH对PC／ABS兼具增容增韧作用。对共混制得的复合材料研究表明，弹性体的添加显著增加了PC／ABS合金的抗冲击效果，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50.3KJ／m²，增幅达56.31％。复合材料的低温横断面SEM分析显示，弹性体形成的弹性核粒径小于0.4μm，且在树脂基体中的分散均匀，大小均一，微团间相容程度得到提高。分散在树脂中的弹性体基质EVA通过自身构象改变来吸收和分散冲击能量，协同MAH官能团的反应增容作用，达到增韧PC／ABS合金的效果。EVA-g-MAH的添加增大了PC／ABS合金的加工扭矩。纳米碳酸钙直接填充PC／ABS合金没有增韧效果。经甲基丙烯酸甲酯和丙烯酸丁酯双单体聚合包覆的纳米碳酸钙形成了核壳结构增韧复合微粒。在双螺杆挤出机中采用二次挤出法制备出PC／ABS／纳米碳酸钙复合材料。研究纳米碳酸钙复合微粒对PC／ABS合金力学性能的影响表明：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由32.18KJ／m²提高到41.3KJ／m²；2份改性纳米碳酸钙对材料的拉伸强度有一定程度的提高。利用纳米颗粒的小尺寸效应和刚性，其在合金体微观区域内将受到的点应力分散为颗粒表面应力，引起周围树脂大面积微开裂，通过剪切流动起到增韧PC／ABS合金的作用。纳米CaCO₃复合微粒具有无机纳米颗粒和弹性体双重协同增韧的作用，其表而的聚合物分子链与基体树脂起到嵌段增容作用同时提高了颗粒的分散效果。这种新型增韧剂用量少，成本较低，为PC／ABS合金性能的提高提供了一个较好的选择。更多还原

【Abstract】 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.更多还原