| With the rapid development of the electrical appliance with high power,electronics,automotive field, the problems of heat-dissipation is one of the reasons forlimiting these fields’ development. The thermal-conductive polymer materials mainlycontain two kinds of materials:1the materials which can intrinsically conduct heat,usually include polyacetylene, polyaniline, polypyrrole and polymer materials withperfect crystal structure and so on;2the composites filled with the fillers with highthermal conductivity, which are BN, carbon fiber,carbon nanotube, graphite,grapheneand so on. In the paper, the research for the thermal-conductive nanocomposites weremainly represented.Since2004, great progress for the research of thermal-conductive nanocomposit-es has been made by the discovery of graphene, which owns super high thermalconductivity of5300W/mk, which is much higher than thermal conductivities ofcarbon nanotube and diamond. Besides, graphene, has been drawing much attentionfrom researchers of another various fields and has raised the hot wave for its study,owning to its’ various fascinating physics performances. However, It is difficult torealize to large-scaly produce graphene with good quality in the premise of low-cost,easy-operating and high-efficiency for industrial application. Much problems arise forthe preparation for heat-conductive graphene nanocomposites.In the study, ball milling, a common industrial technique, was brought in thepreparation for graphene nanocomposites. The principle of mechanically ball-millingexfoliation method for GNPs is that the pure shear among balls of various diametersis able to break the powerful van der Waals-like forces of the carbon-atom layers andat last GNPs emerge gradually. At the same time, the new obtained GNPs arewrapped up by polymer matrix. Thus this method possess many advantages. It isconvenient for operation, lower-cost and can be easily scaled up into mass production.In order to compare with another fillers, many other methods and thermal-conductivefillers were applied. In final, ball billing was used for the production for graphene. The main points of this works is as followed：(1) PC,ABS heat-conductive composites: Melt mixing and solution mixing methodswere applied for the preparation of composites, which were characterized byscanning electron microscopy(SEM),Tci thermal analyzer, differential scanningcalorimetry(DSC), Thermo gravimetric Analysis(TG). The result were as follows:Compared the two kinds of composites based on PC/ABS prepared in solutionmixing method and melt mixing method, the front showed betterthermal-conductive property, for which the highest thermal conductivity rose to4.21W/m K, While the best result of the ABS composites is2.89W/m K. In all,PC composites demonstrated better heat-conductive property than ABScomposites.(2) Epoxy resin composites prepared in the sonication solution mixing method: Thecomposites were filled with AlN,carbon fiber, carbon black, graphite, whichwere also characterized by above instruments. The results were as follows：Contrast these type of composites filled with AlN, carbon fiber, carbon black andgraphite, the composites filled with KNG180and mixed filler showed bestthermal-conductive property.(3) The graphene/epoxy nanocomposites prepared by ball milling method: Based onthe composites prepared in sonication mixing method, ball milling method wasused to preparing the graphene/epoxy nanocomposites. The result are asfollows：Compared with the composites prepared in sonication mixing method,the graphene nanocomposites was made vis ball milling, which showed betterthermal-conductive property. For the composites with filler weight of25wt%，the thermal conductivity is2.69W/m K. Besides, graphene nanosheetsseparated from epoxy mixing with good qulity were prepared via ball milling.(4) The graphenes prepared by ball milling method: Based on our groups’ research onball milling method, improvement steps were done in the study. The results showwe have succeeded in preparing graphene with high quality. |
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