Study On Surface Modification Of Bentonite With Coupling Agent

This paper studied the surface modification of bentonite with aluminatecoupling agent and silane coupling agent in order to strengthen the compoundeffect between bentonite and polymers. The effects of the the modificationtemperature, the dosage of coupling agents and the modification time on thesurface modification of bentonite were researched by single factor experiments.Besides, the modified bentonite was characterized through the method ofsettling velocity, activation index and viscosity. And the best processingconditions of the surface modification of bentonite with aluminate couplingagent and silane coupling agent were mastered. Meanwhile the modifyingmechanism was analyzed by IR spectrogram.The conclusions can be shown as follows:1. When the modification effect was evaluated by the activation index, thelower was the activation index, the better was the modification effect, which wasdifferent from the results assessed by other evaluating standards. 2. The method that settling velocity, activation index and viscosity wereused to evaluate the modification effect of bentonite has the advantages ofsimplicity, convenience and low cost.3. The discrepancy of the result was not obvious when the effect ofmodification was evaluated with the viscosity of bentonite, so as to the effect ofmodification was not remarkable. Therefore the settling velocity and theactivation index were proposed evaluating the effect of modification.4. The best processing conditions of bentonite surface modification withaluminate coupling agent were obtained that the modification temperature was110℃, the dosage of coupling agents was 3wt%, and the modification time was30min. And the processing conditions of bentonite surface modification withsilane coupling agent were the best that the modification temperature was 130℃,the dosage of coupling agents was 1.4wt%, and the modification time was40min.5. The analysis of the surface modification mechanism of bentonite showedthat chemisorption and physisorption action coexisted in the modificationprocess of bentonite with the above mentioned agents.6. The comprehensive evaluation results of modifide bentonite showed thatthe modification effect of bentonite with silane coupling agent was better thanthat with aluminate coupling agent.