Preparation And Property Of High Temperature Resistance Composite Materials

Composite material is defined as combination of materials with two or more different physical and chemical properties with specific properties. The performance of various materials to complement each other to create synergy, the comprehensive performance of the composite material is superior to the original composition to meet different requirements. Polymer matrix composites based on organic polymer, by composite with fiber or other materials significantly enhance the performance of composite materials, is a very important class of composite materials. The most obvious feature of polymer matrix composites is that the performance of composite materials can be prepared according to the different needs of different types. PI as a polyimide material, itself is a high temperature polymer; layered silicates as inorganic salts, itself is a kind of fire-resistant material. Therefore, high temperature insulation composites with excellent properties can be prepared by them. Few reports were found to study on the cladding and filling of organic high temperature-resistant polymer with silicate salts.In this paper, two kinds of silicate salts:vermiculite and montmorillonite were used to coating and filling PI, which was used as continuous phase. The main research work was listed as below:By sand milling, natrium ion modification, intercalation, second milling and other methods, exfoliated vermiculite with thin layers and large radius and thickness ratio was prepared. The impact of c(NaCl) on the cation exchange capacity of vermiculite were discussed; also the impact of sedimentation time of vermiculite particle size and distribution were studied. By XRD, FTIR, TGA, TEM, particle size testing to characterize the vermiculite of different stages, finally get the ideal exfoliated vermiculite. The results show that:During the process of natrium ion exchange, in a certain range of concentration of sodium chloride, the increasing of sodium chloride can promote the ion exchange process to get an ideal ion exchange capacity of vermiculite.The composite material was prepared by coated and filling vermiculite to PI. Test the high temperature insulation of composite materials. The high temperature insulation, deformation of composite materials with different amount of vermiculite was studied. The results showed that: high temperature insulation of composite materials coated with vermiculite has significantly improved, and with the increase in the percentage of vermiculite content in the composite, deformation rate decreases. When the percentage of vermiculite content increased to 70%, high temperature insulation of composite materials increased slowly.Montmorillonite is a layered silicate with flexible and film formation. Factors were disscused on the film-forming process to explore the best technology, so that montmorillonite membrane was made. On the basis of its excellent film-forming, composite materials was made by using montmorillonite to coating with PI fiber.The other kind composite material was prepared by coated and filling MMT to PI. Test the high temperature insulation of composite materials in different temperature. The results showed that:the same as vermiculite, high temperature insulation of composite materials coated with montmorillonite have increased significantly. It shows that the composite material coated with montmorillonite has better properties than with vermiculite.