四针状氧化锌晶须/PP导热绝缘复合材料的制备与性能研究  

Study on the preparation and properties of thermally conductive and electric-insulating T-ZnOw/PP composites

作　　者：李光吉[1] 冯晖[1] 童奇勇[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《材料研究与应用》2008年第4期511-516,共6页Materials Research and Application

摘　　要：以聚丙烯（PP）为基体，四针状氧化锌晶须（T-ZnOw）为导热填料，用双螺杆挤出机制备导热绝缘的T-ZnOw／PP复合材料．在ω（T-Znλ）为0～30％的范围内，探讨了T-ZnOw的用量对T-ZnOw／PP复合材料的热导率（λ）、体积电阻率（ρv）、力学性能和加工性能的影响．结果表明，随T—ZnOw用量的增加，T—ZnOw／PP复合材料的热导率提高，体积电阻率下降；材料的拉伸强度、弯曲强度以及冲击强度均随T—ZnOw用量的增加呈先增大后减小的趋势。而熔体流动速率则呈增大趋势．当T-ZnOw用量达30％时。材料的热导率达到最大值0．3803W·（m·K）^-1，比纯PP提高了55．9％；体积电阻率达到最小值6．17×10^16Ω·cm，比纯PP降低了64．5％，仍可满足绝缘材料的要求.对其断面结构的观察表明，T-ZnOw的针状结构有利于在PP基体中形成导热通路，从而提高材料的热导率．Thermally conductive and electric-insulating polypropylene （PP） composites were prepared with a twin-screw extruder using tetrapod zinc oxide whisker （T-ZnOw） as thermal conductive filler. The effects of T-ZnOw content on the thermal conductivity （λ）, volume resistivity （ρv）, mechanical properties and processability of the T-ZnOw/PP composites were investigated within the range of T-ZnOw content from 0 to 30%. The results indicate that as the content of T-ZnOw increases, the thermal conductivity of the T-ZnOw/PP composites increases while the volume resistivity decrease; besides, the tensile, flexural and impact strength of the T-ZnOw/PP composites exhibit a tendency to increase firstly and then decrease, andthe melt flow rate exhibit a tendency to increase. The T-ZnOw/PP composite filled with 30% of T-ZnOwpossesses the maximum thermal conductivity and the minimum volume resistivity. The former is 0. 3803 W· （m · K）^-1 , which is 55.9% higher than that of pure PP; and the latter is 6.17× 1016Ω· cm, which is 64.5% lower than that of pure PP but meets the requirements for electric-insulating materials. The obser-vations of the fracture surfaces the T-ZnOw/PP composites by means of SEM show that the tetrapod strucure of T-ZnOw is favorable to the formation of passage for heat conduction, thus increasing the thermal conductivity of composites.

关 键 词：四针状氧化锌晶须 热导率 体积电阻率 绝缘复合材料 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]