The Design,preparation And Pilot-scale Application Study Of NR/silica Master Batch By Emulsion Method

In order to actively respond to the "made in China 2025" initiative to comprehensively promote green manufacturing and accelerate the green upgrade of the manufacturing industry,the rubber industry will face new challenges.At present,the rubber industrial production mainly adopts the traditional mechanical dry mixing process,which has become mature after years of development and improvement,but also has prominent disadvantages,such as large VOC emissions,large energy consumption and poor dispersion of fillers.Therefore,the innovative research and development of mixing process has become the only way for the development of rubber industry.The wet mixing process has attracted much attention because of its good solution to the above problems.As a typical inorganic non-metallic material,silica is often used as a reinforcing material of rubber,and natural rubber is also the most widely used general rubber.Therefore,it is of great significance for the green development of rubber industry to explore the wet preparation of natural rubber/silica(SiO2/NR)master rubber process.In this paper,the parameters of the pilot process were determined through small test experiments,such as the ratio of modifier,the optimal concentration of silica gel,the modification time of silica gel,the compound time of latex and silica gel,and the amount of flocculant,etc.,and the pilot process of SiO2/NR master rubber was designed by wet method.Through the study,the optimal concentration of silica is 15%,the grinding and modification time is 20min,the coupling agent KH590 is 3%,the dispersant AEO-9 is 3%,the prepared SiO2/NR parent gum has better static mechanical properties and dynamic thermal performance,and the parent gum has better strength after solidification,which can be produced by the traditional natural rubber production line.When the dosage of KH590 is fixed,increasing the dosage of AEO-9 can promote the dispersibility of silica in rubber matrix,reduce Payne effect and reduce heat generation.The second part of this paper is to use Si69 liquid phase coupling agent commonly used in the tire industry to modify silica,and wet process to prepare SiO2/NR master gum.By adding emulsifier AEO-9,Si69,which was insoluble in water,was emulsified in silica slurry,and the surface of silica was modified.Were prepared by this method is SiO2/NR masterbatch,but white carbon black masterbatch on the overall performance and dry gap is bigger,speculates that the reason is Si69 not like KH590 hydrolysis and white carbon black surface hydroxyl in the water phase condensation reaction,Si69 only by van der Waals force and hydrogen bonding adsorption on the surface of silica,and coupling agent exists the possibility of inactivation,lowered the efficiency of coupling agent modification.The author expected to further improve the performance of SiO2/NR parent rubber by adding Si69 in late mixing.However,it was found through experiments that adding Si69 did not significantly improve the dispersion of compression heat generation and silica,but the cross-linking density and tensile stress decreased.Adding Si69 mainly played a role in plasticizing.Through the experimental analysis,it was speculated that the active site of silica was occupied by the non-colloidal components in the natural latex during the liquid phase composite process,and Si69 could not be further modified by adding silica in the later stage.