A novel material based on deep eutectic solvents and its application in in-situ modified silica-reinforced styrene-butadiene rubber

In the tread compound of Green tire, silica dispersity is critical for obtaining high-performance rubber composites. Ionic liquids have been successfully applied in improving the dispersity of silica through chemical and physical interaction. However, recent research has found that ionic liquids are harmful to the ecological environment. Meanwhile, the price of them is high. In this paper, the deep eutectic solvents (DESs-Choline Chloride: urea) was synthesized successfully. Then it was directly introduced to prepare silica-filled styrene-butadiene rubber (SBR) compound via an in-situ method. The carbonyl group and amino in DESs could constitute a hydrogen bond with the silanol on the silica surface. The hydroxyl groups were able to react with the silanol groups. The amino groups in DESs could treat as a secondary facilitator, which accelerated the curing rate. The results showed that DESs improved the dispersity of silica effectively and strengthened the interaction between silica and SBR chains. Particularly, the comprehensive performance of the rubber vulcanizates improved with an optimal ratio of bis(3-triethoxysilypropyl)-tetrasulfide (TESPT) to DESs being of 1:1. In addition, the DESs will serve as a novel material in silica-filled SBR composites, which will expand its application in the tire industry.

Automated summary

In the production of Green tires, achieving high-performance rubber composites requires good dispersion of silica, which can be improved through the use of ionic liquids. However, recent research has shown that ionic liquids are harmful to the environment and expensive. In this study, a new solvent called deep eutectic solvents (DESs) was successfully synthesized and used to enhance the dispersion of silica in styrene-butadiene rubber (SBR) compounds. The results showed that DESs effectively improved the dispersion of silica and strengthened the interaction between silica and SBR chains, leading to improved overall performance of the rubber vulcanizates.