导热木质复合材料制备工艺及性能研究

发布时间：2018-04-09 00:07

本文选题：石墨　切入点：微纳米材料　出处：《内蒙古农业大学》2015年硕士论文

【摘要】：本研究以木质纤维为主要材料,微纳米石墨为导热材料,结合人造板技术进行导热木质复合材料的制备及其性能研究。重点通过导热水质复合材料的功能性设计、工艺优化、导热机理的研究,提高木质复合材料的导热性能,并借助扫描电镜从微观分析木质复合材料的导热性能。研究结果如下：(1)复合材料最佳制备工艺为：石墨填充量15%、石墨粒径2500口、偶联剂种类为钛酸酯,在此条件下制备的复合材料其静曲强度为35MPa、弹性模量为17864MPa、内结合强度为0.31MPa、吸水厚度膨胀率为17.1%、导热系数为0.266(W/(m·K))。(2)不同变量因素对复合材料力学性能影响不同,石墨填充量对复合材料力学强度影响最大,石墨填充量从5%提高到15%,静曲强度降低70.7%,弹性模量降低9.3%、内结合强度降低19.8%,而复合材料的吸水厚度膨胀率升高5.8%。2500目石墨的复合材料与300目石墨的复合材料相比：静曲强度降低22%、弹性模量降低4.3%、内结合强度降低6.8%、吸水厚度膨胀率升高3.1%。对复合材料导热系数影响最大的是石墨粒径,其次是石墨填充量。钛酸酯偶联剂的加入可以有效改善复合材料的力学强度和导热系数。(3)微观分析表明：300目粒径石墨与木纤维结合紧密,但是石墨分散不均匀：700目粒径石墨相比300目石墨分散更均匀,能形成一定的“导热网络”结构,使得导热性能提高,石墨颗粒不能与纤维紧密结合,两者之间存在空隙,力学强度下降；2500目粒径石墨与木纤维均匀混合,近乎没有空隙且分散性能好,但石墨与纤维之间主要通过吸附力结合,所以力学强度低。
[Abstract]:The research results are as follows : ( 1 ) The optimum preparation process of composite material is : graphite filling quantity 15 % , graphite particle size 2500 port and coupling agent kind as titanate . The results are as follows : ( 1 ) The composite material has a static bending strength of 35 MPa , elastic modulus decreased by 4.3 % , the internal bond strength decreased by 6.8 % , and the swelling rate of water absorption thickness increased by 3 . 1 % . The effect of titanate coupling agent on the thermal conductivity of composite material could improve the mechanical strength and thermal conductivity of composite material . ( 3 ) The micro - analysis shows that 300 mesh size graphite is tightly combined with wood fiber , but graphite dispersion is not uniform : 700 mesh size graphite is more uniform than 300 mesh graphite and can form a certain " heat - conductive network " structure , so that the thermal conductivity can be improved , graphite particles cannot be tightly combined with the fibers , and voids exist between the graphite particles and the graphite particles , and the mechanical strength decreases ;
The 2500 mesh size graphite is uniformly mixed with the wood fiber , is nearly free of voids and has good dispersion property , but the graphite and the fiber are mainly combined by adsorption force , so the mechanical strength is low .

【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TS653;TB33

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