性能均衡的尼龙6基导热复合材料的结构设计

摘要

聚合物基导热复合材料以其独特的优势,如耐环境性和易于加工成型等特点而被广泛的关注和研究.将与尼龙6 (PA6)具有部分相容性的尼龙11 (PA11)引入尼龙6/氮化硼(PA6/BN)复合材料中,并对其导热性能和力学性能进行了研究.结果发现,在PA6/PA11/BN复合材料中,氮化硼选择性分布在PA6连续相中,PA11相起到体积排除的作用,使得BN在PA6中更有效地形成导热通路,可在较低粒子含量下显著提高复合材料热导率.同时,韧性较高的尼龙11亦起到改善复合材料力学性能的作用.当PA6/PA11体积比为7/3、氮化硼体积分数为20％时,PA6/PA11/BN复合材料热导率达到1.96 W/(m·K),与同等BN含量的PA6/BN复合材料的热导率相比提高了约13.7％,且复合材料的断裂伸长率和拉伸强度也同时得到提高,分别提高了86.72％和13.95％.该研究为制备兼具优异导热性能和力学性能的新型聚合物基导热复合材料提供了一种思路.%Polymer based thermally conductive composites were studied due to their advantages such as excellent environmental resistant and good processibility.In this work,polyamide 11(PA11),which is partially miscible with polyamide 6 (PA6),was introduced into PA6/boron nitride (/BN) composites.Thermal conductivity (TC) and nechanical properties of the obtained PA6/PA11/BN composites were investigated.The results show that BN selectively is distributed in PA6 continous phase while PA11 phase plays the role of size exclusion in PA6/PA11/BN composites,which makes BN in PA6 more effectively construct thermal conductive paths,thus enhancing the TC of composites at relatively low fillers loading.Moreover,the more flexible PA11 is also good for the improvement of mechanical properties of composites.TC of PA6/PA11/BN composites with the PA6/PA11 volume ratio of 7/3 and BN loading of 20vol％ reached to 1.96 W/(m·K),about 13.7％ higher than that of PA6/BN composite at the same BN loading;meanwhile,both the elongation at break and tensile strength of the composites are improved by 86.72％ and 13.95％,respectively.This study can shed some light on the preparation of polymer based composites with balanced thermal conductivity and mechanical properties.