| Natural rubber(NR)is widely used in automotive,aerospace,sealing and other industrial fields due to its excellent elasticity,insulation and easy processing.Although natural rubber has excellent performance,it still needs to use reinforcing filler to improve its performance.Now,carbon black is still the most widely used reinforcing filler in the rubber industry,but carbon black has disadvantages such as high energy consumption,high production cost and serious pollution in the process of use.In recent years,people try to use natural inorganic minerals as rubber reinforcing filler.In this thesis,natural zeolite was studied.Firstly,the structure and composition of three kinds of natural zeolite were characterized and analyzed,and clinoptilolite was used as reinforcing filler instead of carbon black,and the influence of the amount of zeolite on the properties of natural rubber composites was studied.Then the natural zeolite was modified to improve the dispersion and compatibility of zeolite in rubber matrix.The influence of modified zeolite on vulcanization,dynamic thermo-mechanical properties(DMA)and mechanical properties of rubber composites was studied.The specific research work is as follows:(1)In this thesis,three kinds of natural zeolite structures were characterized by XRD,SEM,XRF and other analysis,and one of the zeolite and carbon black were compounded to strengthen natural rubber,and the influence of the amount of natural zeolite as a substitute for carbon black on the properties of natural rubber composites was studied.The results showed that the three natural zeolites were mixtures of various mineral crystals,and clinoptilolite were selected to be added into the rubber.With the increase of the amount of zeolite,the tensile strength of the composite increases first and then decreases.When the amount of zeolite is 10,the tensile strength of the composite increases by 8.5%compared with the pure carbon black composite.(2)In order to improve the dispersion effect of zeolite in rubber and enhance the interfacial interaction between zeolite and rubber,the natural zeolite was treated with nitric acid and the natural zeolite(NZ)was grafted with bis-(γ-triethoxylsilyl propyl)tetrasulfide(S),and the vulcanization properties of rubber composites were studied.Dynamic thermo-mechanical properties(DMA)and mechanical properties.The results show that the dealuminization of natural zeolite skeleton is hydrophobic after acid treatment,and silane is successfully grafted onto the surface of natural zeolite.The coking time and curing time of the rubber composite with S-HNZ were shortened,and the curing reaction rate was accelerated.In addition,compared with NR,the 300% fixed elongation stress and tensile strength of NR/S-HNZ are increased by 46.7% and 10.8% respectively.DMA results showed that the energy storage modulus(E’)and glass transition temperature(Tg)of NR/S-HNZ were higher than those of NR.(3)In order to reduce the generation of ethanol in the process of silanization,zeolite was modified by green solvent--ionic liquid,and the effects of two ionic liquids,1-allyl-3-methyl-imidazolium chloride(AMI)and 1-butyl-3-methyl-imidazolium tetrafluoroborate(BMI)and zeolite,on filling rubber were studied.The results show that both ionic liquids can improve the dispersity of zeolite in rubber composites.Compared with the unmodified zeolite/rubber composites,the energy storage modulus G’ and loss factor of rubber composites are increased.Both AMI and BMI could effectively enhance the interfacial interaction between zeolite and rubber matrix,and AMI showed better enhancement effect. |
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