Study On Application Of New Silane Coupling Agent And New Carbon Nano Tubes With Coarse Graining Surface Structure In Rubber Composites

The nanocomposite technology is a leading technology in 21st century.Two key factors during the fabrication of rubber nanocomposite are filler dispersion and the interface between fillers and rubber matrix.Silica is a kind of idea filler in making "green tire" with low rolling resistance.However,since silica has many hydroxyl groups on its surface,which lead to a poor compatibility between silica and rubber matrix and a self-aggregate tendency of silica particles,which further results in bad filler dispersion and difficult mixing process.Conventional silane couling agent has proved to be an important silica surface modifier which provides strong interaction between filler surface and rubber martix.However,conventional silanes are generally trimethoxy and triethoxy substituted,which results in the release of quantities of methanol and ethanol during bonding to the filler.The release of these volatile organic compounds(VOC)is harmful to the environment.Besides,using conventional silanes will reduce scorch time.It is well known that the wet compounding method was time-saving,energy-saving and environmentally friendly when compared to traditional dry blending method.Since conventional silanes could not be dissolved in water,wet compounding method may be not suitable.In order to solve the aforementioned problems,conventional silane coupling agent was modified by fatty alcohol-polyoxyethylene ether to fabricate a new kind of silane coupling agent called M-Si69,then they were used to make Silica/NR composites to confirm the function of M-Si69.[3-(triethoxysilyl)propyl]tetrasulfide(Si69)reacted with fatty alcohol-polyoxyethylene ether 9(AEO-9)to synthesize new silane coupling agent,M-Si69.The chemical structure of the resultant M-Si69 was investigated by FTIR,'HNMR and LC-MS.Then M-Si69 was used to modify silica and incorporated into nature rubber latex to obtain nano SiO2/NR master batch.The results show that M-Si69 could be well dissolved in water and can greatly enhance the flocculation effect of silica and NR latex.M-Si69 was added for preparing Silica/NR composites through wet compounding method and traditional dry blending method.The wet compounding method led to more uniform dispersion of fillers in rubbermatrix in contract with traditional dry blending method.Besides,we also compared the properties of Silica/NR composites with M-Si69 and Si69.Furthermore,the properties of Silica/NR composites fabricate with M-Si69 in different amount was investigated.The optimum M-Si69 dosage used in wet compounding method and traditional dry blending method is 10phr and 7.5phr,respectively,since M-Si69 has a higher degree of hydrolysis in silicawater slurry.Carbon nanotubes(CNTs)can be used as functional filler.Because the surface of most carbon nanotubes is smooth and inert,CNTs show weak interaction with the rubber matrix,which restrict the effective performance of CNTs in nanocomposites.In this work,a new kind of surface coarse-grained carbon nanotubes called CNTr were prepared by co-operation with Jiangsu First Element Company.This new kind of carbon nanotubes were used to composite styrene-butadiene rubber for the first time.CNTr is evenly dispersed in rubber matrix after simply blended.The mechanical properties,thermal conductivity and electrical properties of CNTr/SBR composites are improved with the increase of CNTr.When the amount of CNTr increasing.When CNTr is 30 phr,the tensile strength of CNTr/SBR composites is increased by 6 times,the stress in 300%strain is increased by 6.71 times,the thermal conductivity is increased by 1.5 times,and the volume resistivity is reduced to 0.17.The tensile strength,tear strength and thermal conductivity of CNTr/SBR composites were significantly higher than that of N330 carbon black/styrene-butadiene rubber composites.