填料形状对聚酰胺6基复合材料导热性能的影响

Effect of Filler Shape on Thermal Conductivity of Polyamide

首先分别以膨胀石墨(EG)、氮化硼(BN)、氧化铝(Al_2O_3)、氧化锌晶须(T-ZnO_W)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、Al_2O_3、T-ZnO_W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Al_2O_3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Al_2O_3或T-ZnO_W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),Al_2O_3,and zinc oxide whiskers(T-ZnO_W)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,Al_2O_3 and T-ZnO_W 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,Al_2O_3 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 Al_2O_3 and 2.84 W/(m·K)by 2.5 vol% of T-ZnO_W in the mixed fillers with a total volume fraction of 20 vol%.