导热阻燃聚丙烯复合材料的制备与性能研究

发布时间：2018-04-05 01:23

  本文选题：热导率　切入点：阻燃　出处：《北京化工大学》2015年硕士论文

【摘要】：高分子复合材料由于质轻、易加工成型、耐磨损、易于工业化等特点得到广泛应用,但绝大多数高分子材料因导热系数低而在应用上受到极大限制。因此,给予高分子材料良好的热传导能力,可以极大程度上拓宽其应用领域；在高分子复合体系具有良好热传导能力的基础上保证其绝缘性,则对于提高电气及微电子器件的精度、寿命和满足现实中大量绝缘散热场合的需求具有重大积极意义。通常为获取高热导率而采取的高填充导热填料方法,会使共混体系的力学性能受到损害。另一方面,高性能塑料的易燃性是其应用过程中的最大隐患。为避免不必要事故发生,高分子材料的阻燃能力成为衡量其应用价值的重要标准。因此,制备高导热、良绝缘、阻燃效果出色、力学性能优良的多功能性复合材料具有重大意义。具体研究内容如下：1.首先通过熔融混炼法制备Mg(OH)2/PP两相共混体系,表征其导热、阻燃、绝缘和力学性能,并通过SEM观察其微观形貌。实验结果表明,Mg(OH)2添加量达到70 wt%时,共混体系的导热系数提升至0.92 W/(m*k),比纯PP增加了4.1倍；当Mg(OH)2添加量超过60 wt%,共混体系的垂直燃烧等级为UL-94 V-0级,抑烟效果良好；Mg(OH)2的加入不会损害PP良好的绝缘性；SEM照片显示,六角片状的Mg(OH)2颗粒在PP基体中分布均匀,无团聚现象；力学测试表明,在高填充量下,共混体系的弯曲性能有所提高,但各项拉伸测试结果以及缺口冲击强度都显著下降。2.制备了Mg(OH)2/PP/GNPs三元共混体系,对其导热、导电、阻燃及力学性能分别展开表征,并通过SEM观察其微观形貌。实验结果表明,以少量GNPs代替Mg(OH)2后,共混体系的热传导能力即得到显著提升。Mg(OH)2添加量为61 wt%、GNPs添加量为9 wt%时,共混体系导热系数由0.92 w/(m+k)提升至1.58 w/(m*k);GNPs添加量不超过9 wt%时,共混体系具有优异的绝缘性；少量GNPs的加入使共混体系的拉伸性能和抗冲击性能有小幅度提升,并且保持了优异的阻燃效果。3.选用凯夫拉纤维(KF)和聚乙烯-辛烯共聚物(POE)提高共混体系的力学性能。采用熔融挤出法制备Mg(OH)2/PP/增韧填料三相共混体系,比较凯夫拉纤维与POE各自对于共混体系缺口冲击强度、断裂伸长率的改善效果以及对导热、绝缘、阻燃性能的影响。实验结果表明,凯夫拉纤维和POE的使用明显改善了共混体系的冲击韧性,解决了高填充Mg(OH)2所导致的聚丙烯脆性问题,且没有影响共混体系的导热、绝缘和阻燃效果,使本研究具有了重要的实用价值。
[Abstract]:Polymer composites are widely used because of their light weight, easy processing, wear resistance and easy industrialization. However, most polymer materials are greatly limited in application because of their low thermal conductivity.Therefore, giving good thermal conductivity to polymer materials can greatly broaden its application field, and ensure its insulation on the basis of good thermal conductivity of polymer composite system.It is of great significance to improve the accuracy and life of electrical and microelectronic devices and to meet the needs of a large number of insulation and heat dissipation occasions in reality.In order to obtain high thermal conductivity, the mechanical properties of the blends will be damaged by the method of high filling thermal conductivity.On the other hand, the flammability of high-performance plastics is the biggest hidden danger in its application.In order to avoid unnecessary accidents, the flame retardant ability of polymer material has become an important standard to measure its application value.Therefore, it is of great significance to prepare multifunctional composites with high thermal conductivity, good insulation, excellent flame retardant effect and excellent mechanical properties.The specific contents of the study are as follows: 1.Firstly, Mg(OH)2/PP two-phase blend was prepared by melt mixing method, and its thermal conductivity, flame retardancy, insulation and mechanical properties were characterized, and its microstructure was observed by SEM.The experimental results show that the thermal conductivity of the blends increases to 0.92 W / m ~ (-1), 4.1 times higher than that of pure PP when the content of MgO _ (2) is 70 wt%, and the vertical combustion grade of the blends is UL-94 V-0 when the content of Mg(OH)2 is more than 60 wt.The addition of MgOH2 to PP does not damage the good insulation of PP. The results show that the hexagonal Mg(OH)2 particles are uniformly distributed in the PP matrix and have no agglomeration, and the mechanical tests show that the Hexagonal Mg(OH)2 particles are distributed uniformly in the PP matrix, and the mechanical tests show that at high filling amount, the Hexagonal Mg(OH)2 particles are distributed uniformly in the PP matrix.The flexural properties of the blends were improved, but the tensile test results and notched impact strength decreased significantly.Mg(OH)2/PP/GNPs ternary blend system was prepared, and its thermal conductivity, electrical conductivity, flame retardancy and mechanical properties were characterized, and its microstructure was observed by SEM.瀹為獙缁撴灉琛ㄦ槑,浠ュ皯閲廏NPs浠ｆ浛Mg(OH)2鍚，

本文编号：1712595