Study On Preparation Of Pre-modified Silica With Different Modification Methods And Its Application In Ssbr/br

Silica is one of the important fillers for rubber reinforcement.The surface of silica is rich in hydroxyl groups,and has poor compatibility with non-polar rubbers,and cannot effectively play the role of filler reinforcement.Therefore,the industry currently uses silane coupling agent Si69 to modify silica,but it still faces problems that need to be solved urgently.For example,high heat generation during the mixing process of silica,Si69 and rubber production,the material temperature is difficult to control,and the dispersion effect of silica is limited.It is difficult for rubber to eat fillers;energy consumption is high;the release of ethanol gas brings safety hazards and other issues.In this thesis,silica is modified by the combined use of silane coupling agent Si69 and dispersant AEO-9.Three modification methods are used to construct a strong chemical bond between silica and Si69 to improve the organic characters of silica,and fill the pre-modified silica obtained by different modification methods into SSBR/BR to form corresponding composite materials,the structure and properties of the obtained silica powder and composite materials were tested and analyzed.The main contents of the paper include:1.Prepare pre-modified silica(Silica)by spray drying method.Zeta potential analysis shows that the stability of the pre-modified silica slurry is good.CA,FT-IR,BET analysis of pre-modi fied silica powder with different proportions of Si69 and AEO-9 the results showed that Si69 and AEO-9 were grafted onto the surface of the pre-modified silica.Silica/SSBR/BR composites prepared by pre-modified silica when Si69:AEO-9=11:1 has excellent comprehensive performance.2.The modified silica of spray drying method is heat-treated in an oven at 150? for 1 h to obtain the heat-treated modified silica(D-Silica).TGA analysis shows that the actual grafting amount of the modified silica powder is almost the same as the theoretical grafting amount,and total grafting amount is about 10%.Si69:AEO-9=8:4 D pre-modified silica D-Silica/SSBR/BR composites have better static mechanical properties,Si69:AEO-9=3:9 D has better dynamic mechanical properties.3.The pre-modified silica(C-Silica)is prepared by high-speed crush and refinement method,the test analysis of the modified silica in the cyclohexane phase and the water phase shows that the coupling agent is chemically grafted on the surface of the silica,and the grafting amount is both 5.7%;the T90 of the C-Silica/SSBR/BR composite material formed by mixing is obviously shortened,100%/300%constant elongation stress and tensile strength are better than direct dry blending 7.0 Si69.The TEM test of the composite material shows that the modified silica is uniformly dispersed in the rubber matrix.4.The modified silica(pH-Silica)is prepared by adjusting the pre-hydrolysis of the Si69 hydrolysate with hydrochloric acid and mixing the silica slurry.The pH-Silica/SSBR/BR composite material prepared under the conditions of alcohol-water ratio of 9:1 and pH=6-6.5 has excellent properties.Both TEM and SEM results show that the pre-modified silica prepared under this condition is ideally dispersed in the rubber matrix.