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The polymer composite conductive material today people focus on the research and development of a new class of functional materials, which dispersed composite conductive polymer material much attention. It is filled with the conductive particles or conductive fibers, such as carbon black, carbon fibers, metal powder and metal fiber, etc. to achieve the purpose of the conductive, a lightweight, durable, easy to process, and conductive stability, etc. In recent years, the market demand increases. Carbon black and other conductive fillers compared with control added amount can be arbitrary conductivity, low prices, and more varieties. Therefore, the carbon black filled conductive composites much attention. In this paper, a single screw melt blending extruder - hot tensile - quenched new molding method of preparing a carbon black-filled PET / PE compound conductive material, heat drawing purpose is to make the material of the dispersed phase (PET phase) formed in situ in the processing of fibers, and the carbon black is substantially dispersed in the surface of the fiber or fibers, the spacing between the carbon black particles, forming a more conductive pathway, thereby improving the conductive properties of the material, while maintaining or improving material mechanical properties. Experimental content and conclusions are as follows: 1. Carbon black filled PET / PE composite conductive material preparation. Before the experiment, the first raw material PET and acetylene black (CB) was dried. By a certain percentage of mixed PET and CB in the torque rheometer made masterbatch. And then pulverized, the proportion with PE extruded plastic extruder and heat stretched into a sheet, the extrusion temperature is set to the processing temperature of the PET, the purpose of the heat drawing is the PET / CB master batch to form a fiber. Finally, the extrudate was pelletized and was compressed into a plate, in the pressure molding machine, the pressing temperature is set to a processing temperature of PE, PET / CB master batch to form a fiber structure is retained in the pressing process, because at this temperature PET phase solid. Another method of preparation with the above methods is basically the same, just not subjected to heat stretching. 2. Carbon black filled PET / PE Performance Testing and Characterization of conductive composites. The present study, the standard method of determination of the mechanical properties and thermal properties of the composites. Measurement of volume resistivity: When R_v> 10 ~ 8Ω, made of 100 × 100 × 4mm plate, ZC36 type high resistance meter for measuring; R_v <10 ??~ 8Ω DT-9205B type digital multimeter test sample the volume resistivity, in order to reduce the contact resistance of the test, using a silver conductive adhesive to the copper bonded to the both end of the sample surface and allowed to stand for 24 hours, to be silver conductive plastic solidification the trial Xie Zhangqiong: hot drawing secondary PET / PE / CB composite conductive system morphology and properties of impact resistance of the kind of stability after the measurement. The morphology of the composite material with a scanning electron microscope (SEM) observation. 3. Study the composition ratio on the morphology and performance of the composite. The fixed heat drawing ratio of 3%, and changing the carbon black content. The results showed that: with the increased content of carbon black, the volume resistivity of the composite material is reduced when the carbon black content of 12 phr (phr refers to about the parts by weight) per hundred parts of the resin contained in the filler, the volume resistivity of the composite material The sharp decline, then a composite of the conductor by an insulator transition, the value is referred to as the percolation threshold; when the carbon black content to 20 phr, the volume resistivity of the composite material reached a \· Cm. Low content of carbon black (10phr) of the dispersed phase PET fiber, but with the increase in carbon black content, the dispersed phase PET Hill fibrous to granular transition, the mechanical properties of the composite declined. The increase in carbon black content has little effect on the Vicat softening temperature of the material. 4. Research hot stretch composite morphology and performance. The fixed carbon black content of ZOphr, changing the stretching ratio. The results showed that: with the draw ratio is increased, the volume resistivity of the composite material is drastically reduced, and when the stretching ratio to 3.96, little change in its volume resistivity, little change in mechanical properties, about 10, Q · Cm. However, with the draw ratio increases, the dispersed phase of the composite material by particulate oriented state transition, i.e. the dispersed phase occurs orientation. 5. Compatibilizer composites. The fixed heat draw ratio of 3.96, while maintaining of PET / PE / the CB the ratio of 15/85 and 80, to change the content of the EVA. The results showed that: with the compatibilizer EVA increased, a sharp increase in the volume resistivity of the composite material, but little change in mechanical properties. 6. Preliminary analysis of the PTC effect of PET / PE / CB conductive composites. The same processing conditions, PET / PE 70/25 (PET / CB is 3/2) a composite material of the PTC composite material of the intensity ratio of 30/70 of a high magnitude, but their PTC intensity is weak, approximately between 1 - 2 orders of magnitude. The other conditions are the same, changing heat drawing ratio, the composite PTC intensity minimal change. 7. Analysis of the crystalline properties of PET / PE / C Day conductive composites. , Hot stretching in the same carbon black content increase can improve the crystallization temperature of the composite material, the material easier to crystallization, and accelerate the crystallization rate of the material, while reducing the melting point of the PE, increasing the degree of crystallinity of PE. In same heat stretching ratio, the increase in carbon black content of the crystallization temperature of the composite material can be reduced, so that the material is not easy to crystallization, and to reduce the crystallization rate of the material, while increasing the melting point of the PE, the degree of crystallinity of PE also improved. But PE ability crystalline PE phase crystallization characteristics of these materials are not a big difference.
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