| Natural rubber（NR）modified some double bonds to obtain epoxidized natural rubber（ENR）.The pure use of epoxidized natural rubber（ENR）is limited by the immaturity of the modification process,resulting in unstable performance.The combination of epoxidized natural rubber（ENR）and natural rubber（NR）can effectively utilize epoxidized natural rubber（NR）.Rubber（ENR）to improve the comprehensive properties of natural rubber（NR）.In this paper,in order to improve the comprehensive properties of natural rubber（NR）and silica composite materials,natural rubber（NR）and epoxidized natural rubber（ENR）are used together,and the combined rubber with excellent performance is prepared by wet mixing.The effects of epoxidized natural rubber（ENR）and wet mixing process on properties and microstructure were tested and analyzed by infrared analysis,mechanical properties,vulcanization characteristics,Pyane effect,DMA analysis and scanning electron microscopy.In this paper,epoxidized natural rubber（ENR）with an epoxidation degree of about 35% was prepared.First,the epoxidized natural rubber（ENR）was compounded with silica to test its comprehensive properties.The results show that the laboratory-made epoxidized natural rubber（ENR）has excellent performance,and then it is compounded with natural rubber（NR）to dry-mix silica reinforced rubber.According to DMA analysis,when the ratio of natural rubber（NR）to epoxidized natural rubber（ENR）is 90/10,only one glass transition temperature is measured as-42.28°C,indicating that the two rubbers are very compatible.Good,and at this ratio,the wet skid resistance and rolling resistance of the rubber are effectively improved.Its mechanical properties are also better than that of pure natural rubber（NR）and silica composites.Therefore,it is feasible to apply epoxidized natural rubber（ENR）to natural rubber（NR）.In this paper,silica and epoxidized natural rubber（ENR）/natural rubber（NR）are mixed by wet mixing,and the silica is made into a 10% mass fraction of dispersion and mixed with latex to coagulate and dry.The samples were tested after vulcanization.The results show that the rubber samples obtained by the wet mixing process still have excellent mechanical properties,and the tensile strength reaches28.49 Mpa,and the properties of the composite materials obtained by wet mixing are the same as those obtained by dry mixing.It can be seen from the thermogravimetric analysis that the residual amount of pure natural rubber（NR）and silica obtained by wet mixing is only 21%.When the compound ratio of natural rubber（NR）and epoxidized natural rubber is 90/10,the residual amount obtained by thermogravimetric analysis can reach 24%.This shows that epoxidized natural rubber（ENR）can not only improve the comprehensive properties of the rubber,but also allow more silica to remain in the rubber during wet mixing.By scanning electron microscope analysis,the dispersion of silica is uniform.This shows that wet mixing can be used in composites of epoxidized natural rubber（ENR）and natural rubber（NR）.In this paper,the silica sol is used as the source of silica,and the silica sol is added to the rubber latex during wet mixing to generate silica in situ during the coagulation of the rubber.As a uniformly dispersed colloid,silica sol can effectively improve the uneven dispersion effect caused by silica dispersion,and the particle size of silica sol is much smaller than that of silica dispersion,which makes the composite obtained by silica sol.The performance of the material is better.Through the analysis of mechanical properties,it is found that when the ratio of epoxidized natural rubber（ENR）to natural rubber（NR）is 10/90,the tensile strength can reach 30.47 Mpa.Silica sol is a good silica source.In the thermogravimetric analysis,the residual amount is only 19%,which is quite different from the residual amount of wet mixing,which shows that the process of wet mixing needs further improvement. |
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