| Conductive polymer has aroused great concern in recent years. The research and production of polymer insulator promote the development of polymer industry in the past with the rapid development of electronic information industry and the aviation industry. It requires good processing properties and special performance which contains light, electricity, magnetism, sound and so on. People regard semiconductor, conductor, as well as superconductor to research more and more.In this paper, on the basis of this research group, using a simple melt blending method, preparaed for nylon6(PA6)/expanded graphite (EG) composites by low temperature plasma treatment on carbon fibers which as reinforcing and toughening filler. Make a study on material microstructure, electrical properties, crystallization, rheological behavior, mechanical properties and also discussed the problem in the process of twin-screw extruder amplification. And then we tackle with the basic problems which encountered in the analysis formulation and process on the system performance. Finally, we propose the appropriate solution.The innovation points of this paper are that:select CF which by the surface treatment of low-temperature plasma processing as enhanced conductive material to preparaed new high-strength conductive composite materials. Plasma processing method is clean and efficient characteristics and it is the future trend in the material surface treatment methods. In addition, production in conductive composite materials amplification of the experimental process with low density, expansible graphite we show the methods of airtight transportation and forced feeding system integration as way of feeding. It is a good method in the production process to tackle with the dust pollution problems and feeding problems which bring light packing way. In addition, in twin-screw extrusion process, selectivity of polymer matrix is very good. In the preparation of different polymer-based conductive composite actual application, promotion has the important meaning. The main results are as follows: 1. Low temperature oxygen plasma treatment and preparation for PA6/EG/CF conductive composite materialsUse CF as a reinforcing material which surface-treated by low temperature oxygen plasma treatment on, we prepared the PA6/EG/CF conductive composite materials by melt blending method. With the electrical properties of CF, they can improve the electrical conductivity of composites performance through the coordination and expansion of graphite conductive. With its excellent mechanical properties improved the mechanical properties of materials, and the quality of the shares when the CF is15phr, the conductive properties while maintaining the basis of material, effectively improve the mechanical, tensile and bending strength to118MPa and178MPa. That is to say respectively P A6/EG composite2.6times and2.3times the strength of composite materials has been greatly improved. The use of DMA, DSC and TG study on the CF and other methods PA6/EG system of dynamic mechanical properties, electrical properties, mechanical properties and thermal properties and other effects.2. Influence of surface properties by low temperature plasma surface treatment on carbon fiberWith oxygen, argon plasma surface treatment on carbon fiber, by SEM, DMA, EPR, AFM and othersurface characterization, the results showed that after plasma treatment the surface properties of CF has greatly improved. Through a series tests of electrical conductivity and mechanical properties, indicating after plasma treatment the combination of fiber and matrix increased capacity. PA6/EG/CF conductivity of conductive composites and mechanical properties were all improved.3. Study on process enlarge the production of new strength conductive composite materialsBased on the excellent performance shown of PA6/EG/CF conductive composite, by the twin screw extrusion method, we prepared PA6/EG/CF conductive composite. Investigated raw material formulation and manufacturing process performance. By SEM, DMA, etc characterized composites, results showed that PA6have good compatibility with CF. Through a series of electrical conductivity and mechanical properties of the test, by the twin-screw extrusion method, mechanical and thermal properties of PA6/EG/CF conductive composites has increased, but with the components of the conductivity of the material decreased.4. Problems during the enlarge experimental process and the corresponding solutionsAmplification experiments in the extrusion process, in order to prevent degradation, and reduce the residence time of materials, we can use high speed CF beam while reduce the number or the number of low-K CF.In order to prepare low-fiber content of the conductive composite material, it maybe under high screw speed for increasing the degree of shear and resulting in over-cut. Therefore, to increase the number of CF beam, the conditions for preparation of medium speed high fiber content of conductive composite materials. In addition, the composite melt (245℃) showed significant shear thinning behavior, so the twin-screw extrusion process resulting in the high shear rate melt fracture phenomenon, lead to a large number of expanded graphite precipitated from the melt reduce the conductivity of the material. Therefore, in twin-screw extrusion process, if the mass fraction of EG and CF are too high,it should be medium or low screw speed. Expanded graphite filler material is less dense, so the extrusion process used in custody transfer and forced feeding, and effectively solved the problem caused by dust pollution and feeding in the production process. |
PDF Full Text Request