填料形状对聚酰胺6基复合材料导热性能的影响

摘要

首先分别以膨胀石墨(EG)、氮化硼(BN)、氧化铝(Al2O3)、氧化锌晶须(T-ZnOw)为填料,采用熔融共混法制备了聚酰胺6(PA6)基导热复合材料,研究了填料形状对复合材料导热性能的影响;在此基础上,再以EG为主填料,分别与BN、Al2O3、T-ZnOw复配填充改性PA6,考察了复配填料形状、含量对复合材料导热性能的影响.结果表明,片状EG较其他填料对PA6树脂的热导率具有更好的提升效果;复配填料中小粒径填料Al2O3有助于打开并进入EG的片层结构,形成更加完善的导热网络,发生协同效应;当复配填料总含量固定为20％(体积分数,下同),BN或Al2O3或T-ZnOw含量分别为7.5％、5％、2.5％时,复合材料的热导率分别达到最大值:3.05、3.10、2.84 W/(m·K).%Thermally conductive polyamide 6 (PA6)-based composites were prepared through a melt-blending method by use of expanded graphite (EG),boron nitride (BN),Al2O3,and zinc oxide whiskers (T-ZnOw) as functional fillers,and effect of filler shape on thermal conductivity of the composite was investigated.Furthermore,EG was used as a major thermally conductive filler to compound respectively with BN,Al2O3 and T-ZnOw so as to confirm the role of filler type in the improvement of thermal conductivity of the composites.The results indicate that EG had a better enhancing effect on the thermal conduction of PA6 matrix than the other three.As a small-size filler,Al2O3 can help to open the layers of the lamellar EG,thus forming a more perfect thermally conductive network and leading to a better synergistic effect accordingly.PA6-matrix composites achieved a maximum thermal conductivity of 3.05 W/(m · K) by 7.5 vol ％ of BN,3.10 W/(m ·K) by 5 vol ％ of Al2O3 and 2.84 W/(m · K) by 2.5 vol ％ of T-ZnOw in the mixed fillers with a total volume fraction of 20 vol ％.