Study On Adhesion Mechanisms And Technological Parameters Optimization Of Heat Vulcanization Of Natural Rubber And Metal Composite Structure

Following with the development of modern industry, in many cases, natural rubber and metal are combined together to obtain composite structure with higher strength and durability taking the advantage of the elasticity of rubber and rigidity of metal. Now, natural rubber becomes the first choice materials for rubber-metal structure because of its high elasticity characteristic.Currently, the series of Chemlock adhesives is commonly used as adhesive for natural rubber-metal structure in our country and have no property rights of our own; furthermore, its ingredients and bonding mechanisms are also not clear. In this paper, the adhesive ingredients commonly used in natural rubber-metal structure and bonding interface are intensively studied via gel permeation chromatography analysis, infrared spectroscopic analysis, nuclear magnetic resonance (NMR), and X-ray diffraction and so on. Through establishing the rubber-metal bonding model, the bonding mechanisms of natural rubber-metal material is revealed effectively. The results show that the substrate of CH205 primer is compose of soluble phenolic resin and chlorinated natural rubber; filling materials is mainly compose of TiO2, ZnO and little unknown gray component; solvent is compose of 4-methyl-2-pentanone and mixed xylenes. The substrate of CH220 top adhesive is chloric high polymer which is polymerized by chloric monomer; filling materials is compose of carbon black and little PbO; solvent is compose of perchloroethylene and mixed xylenes. In rubber-metal bonding model, the diffusivity of CH205 and CH220 is good, and transition layer will be formed between them. CH205 adhesive will link with Fe or other oxides to form a few chemical bonds during the vulcanization process. Under the forming pressure, molecule in CH220 and natural rubber will close to each other, and when the distance between them reduce to certain value, adsorption will occur, which will be the main source of bonding strength. On the basis of above research, the bonding technological parameters of heat vulcanization of natural rubber-metal composite structure is optimized.