Preparation And Study On Properties Of Thermally Conductive Polypropylene Composites

With the development of science and technology and economy,industrial manufacturing and application hope materials havesmall density,easy processing,excellent mechanical properties,chemical resistance,electrical insulation,low cost and other excellent characteristics.Polymer materials are widely used in aerospace,national defense,transportation,chemical industry,electronic and electric fields because of their excellent properties,but the low thermal conductivity of polymer materials limiting the application in the field of heat transport,so improving its thermal conductivity and maintaining other characteristics has become a hot spot of research.In this paper,the thermally conductive polymer matrix composites were prepared by melt blending method with aluminum nitride(AlN)and boron nitride(BN)as filler and polypropylene(PP)as the matrix.For the materials prepared,from the angle of material researching performance testing of thermal and mechanical and microstructural aspects and characterization of different formulations of materials,from the angle of engineering thermal physics using heat conduction model calculate and analysis of thermal performance of composite materials.Through these two aspects of work,explore the key factors that affect the thermal conductivity of composite materials,in order to provide theoretical and practical reference for improving the thermal conductivity of composite materials.In particular,the work of this paper includes:(1)with three different particle sizes of AlN as filler,PP as matrix,using the double screw extrusion mechanism for thermally conductive composites,test and characterization of thermally conductive composite material is prepared by SEM,TGA,DSC,flash method apparatus etc.,the results show: the thermal conductivity of the composites increases with the increase of AlN content in general,and the selection of appropriate filler particles can help to satisfy the requirement of material preparation as well as the increase of thermal conductivity;(2)With Al N and BN as filler,PP as the matrix,making the preparation of mixed filled thermally conductive composite materials and to carry out testing and characterization,the results show: by melt mixing method can make two kinds of filler dispersed in PP matrix,keeping the mass fraction of AlN is 30%,the thermal conductivity of composite materials increases with increasing the mass fraction of BN,and was significantly greater than the composite filling rate of only AlN,it shows two kinds of fillers on the thermal conductivity of filler the composite lifting effect is more obvious.(3)with poly dopamine modified BN as filler,PP as the matrix,making the preparation of thermally conductive composite materials and to carry out testing and characterization,the results show: the thermal conductivity of composite materials increases with increasing the mass fraction of BN,surface modification of thermal conductivity and the degree of composite material can exist complex relationships instead,over the surface of treatment may result in the thermal conductivity is low,the reason is the polydopamine hinders heat transfer.