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PC is thermoplastic engineering plastic and has excellent overall properties. It is odorless, tasteless, non-toxic, rigid and resilient, and has outstanding impact strength and dimensional stability and higher heat resistance and cold resistance, known as a transparent metal. It is widely used in electrical and electronic products, automobiles, machinery manufacturing, aerospace, computers and CD-ROM technology. However, PC scratch-resistant property on the surface is poor, largely reduced the beauty level of products, and the scratch on the product surface can lead to stress concentration, so the applications of PC are subject to certain restrictions. In order to expand the application of PC in the high-end products,it need be modified to impove its scratch-resistant property. At present, the main measure of impoving scratch-rasistant property in the industrial production at home and board is coating UV on the surface of PC substrate.The scratch-resistant property of PC was impoved through filling modification in this paper, and the thermal properties, mechanical properties, melt flow property, melt rheological properties and wear-rasistant propertiesof PC modified systems were studied. The specific research and the results achieved were as follows:(1) The scratch-resistant mechanism of silicon whiskers was analyzed, and the effects of silicon whiskers with different content on the modified PC system were studied. It showed that the modified PC system had the best overal performance, when the content of silicon whiskers reached 5%, the heat distoration temperature was 133.3℃, and the tensile strength was 66.03MPa, and elongation at break was 7.62%, and the bending strength was 78.56MPa,and the notched impact strength was 7.32 KJ/㎡, and melt index was 32.96g/10min,and K was 736.631,and n was 0.843,and pencil hardness was H.(2) The scratch-resistant mechanism of silicone powder was analyzed, and the effects of silicone powder with different content on the modified PC system were studied. It showed that the tensile strength and the bending strength and melt index and pencil hardness increased with the increase of the content of silicone powder, but the notched impact strength remained unchanged, the elongation at break decreased, and the Non-newtonian of modified PC melt was weakened.The best midified recipe in this system was:PC + 5% silicon whiskers + 1% silicone powder. The heat distoration temperature was 133.8℃and the tensile strength was 69.04MPa, and elongation at break was 6.94%, and the bending strength was 89.28MPa,and the notched impact strength was 10.11 KJ/㎡, and melt index was 45.81g/10min,and K was 595.692,and n was 0.883,and pencil hardness was 2H.(3) The scratch-resistant mechanism of scratch-resistant agent was analyzed, and the effects of scratch-resistant agent with different content on the modified PC system were studied. It showed that the tensile strength and the bending strength and melt index and pencil hardness increased with the increase of the content of silicone powder, but the notched impact strength and the elongation at break decreased, and the non-Newtonian of modified PC melt was weakened. The best midified recipe in this system was: PC + 5% silicon whiskers + 1.2% scratch-resistant agent. The heat distoration temperature was 136.8℃, and the tensile strength was 72.61MPa, and elongation at break was 6.07%, and the bending strength was 84.99MPa,and the notched impact strength was 5.13KJ/㎡, and melt index was 42.36g/10min,and K was 572.680,and n was 0.898,and pencil hardness was 2H.(4) The scratch-resistant mechanism of PTFE powder was analyzed, and the effects of PTFE powder with different content on the modified PC system were studied. It showed that when the content of PTFE powder was below 5%, the thermal properties and the mechanical properties decreased, but the melt flow property was improved, but when the content of PTFE powder was above 5%, the thermal properties and the mechanical properties and the flow property were all decreased. The best midified recipe in this system was:PC + 5%PTFE powder. The heat distoration temperature was 126.7℃, and the tensile strength was 37.44MPa, and elongation at break was 4.23%, and the bending strength was 65.07MPa,and the notched impact strength was 5.2KJ/㎡, and melt index was 47.06g/10min,and K was 484.621,and n was 0.865,and pencil hardness was H.(5) By analyzing and comparing with the thermal properties, the mechanical properties, the melt flow properties, the melt rheological properties and wear-rasistant properties of different PC modified systems, the best modified recipe of PC scratch-resistant modification was obtained: PC + 5% silicon whiskers + 1% silicone powder.
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