Study On The Preparation Technology And Characterization Of CNTs/NR Compound By Wet-mixing

Carbon nanotubes(CNTs)are not only one of the most promising carbon materials,but also the important fillers of natural rubber(NR).However,it is easy to agglomerate in the matrix,which is an important reason to hinder its promotion.Compared with the traditional dry mixing,wet mixing,as a new rubber mixing method,has been widely studied for its energy saving and environmental protection.The purpose of this paper is to improve the dispersion of filler in NR by wet mixing process,and further improve the comprehensive properties of composite materials.Firstly,based on the wet mixing process,CNTs and carbon black(CB)were used as fillers to explore the influence of different process on the composite properties.The results show that the composite material(carbon tube carbon black masterbatch method)prepared by dissolving two fillers in natural latex at the same time to prepare latex dispersion after flocculation is superior to the composite material(carbon tube masterbatch method)prepared by dissolving carbon nanotubes in natural latex first and then adding carbon black into the mixer.SEM and RPA2000 analysis show that the filler has good dispersion under the former process conditions,so it is determined to be the process preparation method for subsequent research.The effect of different ratio of CNTs and CB on the properties of wet mixed rubber was studied by using "carbon tube carbon black masterbatch process".It is found that when the mass fraction ratio of carbon black / carbon nanotubes is 35/6 and 30/8,it is better than the 2 ratios of 40/4 and 25/10,and the reinforcing effect of natural rubber is better.Under the same packing ratio,wet-mixing compound materials has better tensile,tear and wear resistance than dry-mixing compound materials.Next,the effect of CNTs modified by physical grinding on the properties of wet mix was studied.With the increase of lapping times,the vulcanization rate of composites is obviously improved,and the tensile and tear properties are significantly increased.It is mainly due to the fact that the length of carbon nanotubes will be refined by full grinding,so that they can be fully combined with carbon black to form a stronger filler network in natural rubber and improve the comprehensive properties of composite materials.Finally,in order to expand the industrial application of wet mixing,this paper blends the CNTs/NR compound by wet-mixing with SBR,which has the advantages of both NR and SBR,and prepares the high-performance blend composite for tire tread rubber.According to the different needs of practical products,the composite materials with the ratio of 80/20 and 20/80 were prepared respectively.The results show that when the ratio of fillers is 30/8,when the ratio of fillers is 80/20,the elongation at break is the largest and the tear strength is the highest.When the ratio of fillers is 20/80,the wear resistance is the best.