填充型聚丙烯基导热复合材料的制备及性能研究

发布时间：2018-06-29 22:33

本文选题：聚丙烯 + 逾渗理论　；参考：《福建师范大学》2015年硕士论文

【摘要】：导热聚丙烯复合材料是新型功能性高分子复合材料,在导热散热领域有着广阔的应用前景。本论文以提高聚丙烯(PP)的导热性能,即提高复合材料的导热系数为目的,借鉴导电高分子复合材料的逾渗理论及双逾渗理论,分析逾渗理论及双逾渗理论在导热高分子复合材料导热行为的应用。选用两种不同类型的PP复合体系,其一是与PP相容性较好的苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS),另一个是与PP相容性较差的聚酰胺6(PA6)分别构成PP/SEBS和PP/PA6复合体系,研究导电炭黑及导热填料在复合体系中的选择性分布对导电性能及导热性能的影响。本论文第一章统计了本论文使用的实验原料、实验仪器及测试标准,详细描叙了实验方案和试样的制备和测试的方法。并选定正交表L9(34),设计PP/SEBS复合体系的正交实验。本论文第二章由PP/SEBS复合体系的L9(34)正交实验,探寻PP/SEBS配比、充油量、加料方式和炭黑含量对导电性能的影响,得出最佳方案。以最佳方案为基础,分析填充导电炭黑(CB)分析PP/SEBS/CB复合材料的导电行为和导热行为,并进-步验证正交实验的最优方案；再在PP/SEBS复合体系中填充导热绝缘填料氧化锌(ZnO)和氧化铝(A1203)研究分析复合材料的导热行为及力学性能,在此基础上复配导热填料,并研究复合材料的性能。结果表明：PP/SEBS/CB复合材料的导电行为是典型的导电逾渗现象,复合材料的体积电阻率在CB用量达到临界值后大幅下降,SEBS则有效减少复合材料逾渗突变时CB用量的逾渗阈值；导热绝缘PP复合材料导热效果：ZnO填充优于Al2O3; PP/SEBS体系优于纯PP基体；在PP/SEBS复合体系中,研究不同填料复配效果发现单一ZnO填充的导热系数和力学性能最优。本论文第三章以PP/PA6为基体,先填充导电CB分析PP/PA6/CB复合材料的导电行为和导热行为,及大分子相容剂对复合材料导热、导电性能的影响；再在PP/PA6复合体系中填充ZnO研究分析复合材料的导热行为及大分子相容剂对复合材料导热、导电性能的影响,在此基础上复配导热填料,并研究复合材料的性能。结果表明PP/PA6/CB复合材料的导电行为是典型的导电逾渗现象,PA6有效减少复合材料逾渗突变时CB用量的逾渗阈值,但是效果不如PP/SEBS复合体系；大分子相容剂马来酸酐接枝聚丙烯(PP-g-MAH);加入不利于复合材料的导电性能,但是却稳定了通过CB通路的导电电流；PP/PA6/ZnO复合材料导热系数优于PP/SEBS/ZnO复合材料；研究不同填料复配效果发现单一ZnO填充的导热系数最优。马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯共聚物(SEBS-g-MAH)替代PP-g-MAH能改善复合材料的冲击性能,但导热性能则会降低。使用10 wt%硅铝复合纳米管(PNT)替代等量的ZnO则会进一步提升复合材料的冲击强度和维卡软化温度。
[Abstract]:Thermal conductive polypropylene composite is a new type of functional polymer composite, which has a broad application prospect in the field of heat conduction and heat dissipation. In order to improve the thermal conductivity of polypropylene (PP), that is, to improve the thermal conductivity of composites, the percolation theory and double percolation theory of conductive polymer composites are used for reference in this paper. The application of percolation theory and double percolation theory to thermal conductivity of polymer composites is analyzed. Two kinds of PP composite systems were selected. One was styrene butadiene-styrene block copolymer (SEBS) with good compatibility with PP, the other was polyamide 6 (PA6), which had poor compatibility with PP. The effects of the selective distribution of conductive carbon black and thermal conductive filler in the composite system on the conductivity and thermal conductivity were studied. In the first chapter, the experimental materials, experimental instruments and test standards used in this paper are analyzed, and the experimental scheme and the preparation and test methods of the samples are described in detail. The orthogonal experiment of PP- / SEBS composite system was designed with orthogonal table L _ 9 (34). In the second chapter, by L9 (34) orthogonal experiment of PP- / SEBS composite system, the effects of PP / SEBS ratio, oil filling, feeding method and carbon black content on the conductivity were investigated. Based on the best scheme, the conductive behavior and thermal conductivity of PPP-SEBS / CB composites were analyzed by means of filled conductive carbon black (CB). Then the thermal conductivity behavior and mechanical properties of the composites were analyzed by filling the thermal insulating filler zinc oxide (ZnO) and alumina (A1203) in the PP- SEBS composite system, and the properties of the composites were also studied. The results show that the conductivity behavior of the composite is a typical percolation phenomenon, and the volume resistivity of the composite decreases significantly when the CB content reaches the critical value. The thermal conductivity of PP composites with thermal insulation is better than that of Al _ 2O _ 3 and that of PP / SEBS is better than that of pure PP matrix. In the PP / SEBS composite system, it is found that the thermal conductivity and mechanical properties of single ZnO filled PP / SEBS composites are the best. In the third chapter, the conductive behavior and thermal conductivity of PP / PA6 / CB composites were analyzed by filled CB, and the effects of macromolecular compatibilizers on the thermal conductivity and conductivity of composites were analyzed. The thermal conductivity behavior of the composites and the effect of macromolecular compatibilizers on the thermal conductivity and electrical conductivity of the composites were studied by filling ZnO in PP- / PA6 composite system. On the basis of this, the thermal conductivity fillers were prepared and the properties of the composites were studied. The results show that the conductive behavior of PP- / PA6 / CB composite is a typical phenomenon of percolation. PA6 can effectively reduce the percolation threshold of CB content when the percolation catastrophe occurs, but the effect is not as good as that of PP- / SEBS composite system. Macromolecular compatibilizer, maleic anhydride grafted polypropylene (PP-g-MAH), is not conducive to the conductive properties of composites, but the thermal conductivity of PP- / PA6 / ZnO composites via CB channel is better than that of PP- / SEBS- / ZnO composites. It is found that the thermal conductivity of single ZnO filler is optimal by studying the mixing effect of different fillers. Grafting of maleic anhydride with styrene-butadiene-styrene copolymer (SEBS-g-MAH) instead of PP-g-MAH can improve the impact property of the composites, but the thermal conductivity will decrease. The impact strength and Vicat softening temperature of the composites can be further improved by replacing the same amount of ZnO with 10 wt% Si-Al composite nanotubes (PNT).
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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