Preparation Of Modified Nano-silica And Its Application In Solution Styrene-Butadiene Rubber/Butadiene Rubber Composites

In order to meet the requirements for tire speed,safety,comfort,energy saving and other performance,rubber materials also requires excellent wear resistance,wet skid resistance,rolling resistance and other properties.Nano-silica is one of the most important reinforcing fillers for rubber materials,but its high polarity,easy agglomeration and poor dispersion affect the performance of rubber materials.In recent years,a variety of surface modified silica have been prepared by liquid phase in-situ surface modification technology in our research group,and developed modified silica loaded with Si69,accelerator CZ,and accelerator D,which has good dispersion and reinforcement properties in SSBR/BR.On the basis of previous research,this article took the compound containing double bond as modifier,prepared S-S type and S-U type silica respectively,and studied the effect on the performance of SSBR/BR.In this article,a series of S-S silica with different double bond modifiers were prepared by the liquid phase in situ surface chemical modification method,using silicate as the silicon source and KH570 as the modifier.By adjusting the amount of KH570,a series of different double bond modified silica nanoparticles were prepared and characterized.At the same time,the effects of four processing techniques on the properties of SSBR/BR were investigated.It was found that the grafting of KH570 on the surface of silica decreased the agglomeration,widened the particle size distribution,and the structural parameters were more stable.In the process 1 and process 2,the dispersion of the premix compound in the other compound was poor;the rubber material failed to mix and the process is not feasible.Compared with process 4,process 3(that is,SSBR and BR are first plasticized,premixed,then added S-S-3 and Si69)improved the dispersion in the SSBR/BR,weakened the agglomeration phenomenon,reduced the Payne effect,and weakened the network structure without sacrificing mechanical properties.At the same time,it could improve the vulcanization speed while ensuring the process safety,increased the crosslinking density and the wear resistance,and reduced the rolling resistance.Using the process 3,the effect of S-S silica on the properties of SSBR/BR was investigated.The experiment found that compared with the unmodified S-S-3,after modified with KH570,the processing safety of the rubber was improved,the vulcanization time was shortened and the vulcanization speed was significantly improved.Also,the grafting of KH570 onto the silica surface significantly improved the dispersion of S-S silica in SSBR/BR,reduced the Payne effect,and weakened the network structure.At the same time,the cross-linking density was significantly increased,and the mechanical properties were improved,but the resistance to thermal oxygen aging was somewhat poor.Comparing the "magic triangle"properties before and after the KH570 modification,it can be found that the wear resistance of the modified rubber material was greatly improved,and the wet skid resistance and rolling resistance were improved to some extent.Especially when the addition of KH570 was 0.1 mmol/kg,the overall performance was the best:without compromising the mechanical properties,wet skid resistance was good and rolling resistance was low,which were better than SSBR/BR/Z-1165MP,at the same time could improve the wear resistance to a certain extent.A series of S-U nano-silica were prepared by controlling the amount and type of unsaturated polyesters.Through its structural characterization,it was found that the unsaturated polyester was successfully grafted to the silica surface.After the modification,the oil absorption value and the specific surface area of the silica were decreased,the pore size and pore volume were more stable,the agglomerate size was reduced,and the particle size distribution was wider.The S-U silica was applied to the SSBR/BR.It was found that after grafting the unsaturated polyester on the surface of the silica,the aggregation of S-U silica was weakened,the Payne effect was reduced,the network structure was reduced and the dispersion in SSBR/BR was improved.At the same time,the processing safety was improved,and the crosslinking density was significantly improved.Comparing the "Magic Triangle" performance of the rubber material before and after the modification can be found that the wear resistance of the modified rubber material was greatly improved,but it did not contribute to the wet skid resistance and the rolling resistance.When filled with S-U-2-1 silica,the nanocomposite had the highest cross-link density and the best wear resistance.