Structure And Property Research Of Fibrillar Silicate/rubber Composites For Automobile V-belt

This research innovationally adopted the techniques to substitute the traditional reinforced organic short fibers with crude silicate nano-fibers in the automobile V-belt according to the developing trends of high performance and long life. The paper put much importance on the dispersing techniques of fibrillar silicate (FS) in the HNBR and EPDM matrix and the interfacial design between the fibers and rubber matrix. The primary achievements of this paper focused on the relationship that how the micro-structures and properties of the composites were influenced by the dispersing techniques of in-situ modification (including heat treatment time, category and dosage of coupling agent), curing system and dosage of filler. Some important results were found.For the composites with HNBR matrix cured by phenolic resin, the in-situ modification and dispersion techniques for FS could obviously improve the mechanical properties of the composite. Heat treatment imposed much influence on the micro dispersion of FS and the mechanical properties of the composites and in order to avoid the heat degradation HNBR proper treatment time should be adopted. The coupling agent KH570 was found the optimal interfacial modifier for FS/HNBR composites. Most FS micro-particles could be cleaved into nano-fiber dispersion in the rubber matrix attributed to the strong polarity of HNBR, resulting remarkable filler network effect exhibited by the increasing the storage modulus of the compound. The filler network could be strengthened by both in-situ modification and the increasing dosage of the filler.Similar with the stress-strain behavior of rubber reinforced with short fiber, the FS/HNBR composite presented high modulus, high strength and low elongation. The oriented composites processed by intense shear possessed obvious mechanical anisotropism. And the mechanical anisotropism could be enhanced by in-situ modification and the increasing dosage of the filler.In the composites with EPDM matrix cured by sulfur, the modified FS dispersed and cleaved far worse than in the HNBR matrix because of the non-polarity of EPDM. As a result, the mechanical properties were not effectively improved by the modified FS and the mechanical anisotropism of the composites could not be distinctly observed. However, an "optimal dosage" of coupling agent Si69 still could be found according the mechanical properties of the composite. In the composites with EPDM matrix cured by peroxide, the dispersion of FS could be enhanced by batch processing technique and incorporation of polar EVM and correspondingly the mechanical properties of the composites could be improved.