Optimized End Functionality of Silane-Terminated Liquid Butadiene Rubber for Silica-Filled Rubber Compounds

As the world is shifting from internal combustion engine vehicles to electric vehicles in response to environmental pollution, the tire industry has been conducting research on tire performance to meet the requirements of electric vehicles. In this experiment, functionalized liquid butadiene rubber (F-LqBR) with triethoxysilyl groups at both ends was introduced into a silica-filled rubber compound as a substitute for treated distillate aromatic extract (TDAE) oil, and comparative evaluation was conducted according to the number of triethoxysilyl groups. The results showed that F-LqBRs improved silica dispersion in the rubber matrix through the formation of chemical bonds between silanol groups and the base rubber, and reduced rolling resistance by limiting chain end mobility and improving filler–rubber interaction. However, when the number of triethoxysilyl groups in F-LqBR was increased from two to four, self-condensation increased, the reactivity of the silanol groups decreased, and the improvement of properties was reduced. As a result, the optimized end functionality of triethoxysilyl groups for F-LqBR in silica-filled rubber compound was two. The 2-Azo-LqBR with the optimized functionality showed an improvement of 10% in rolling resistance, 16% in snow traction, and 17% in abrasion resistance when 10 phr of TDAE oil was substituted

Improved Productivity of Naringin Oleate with Flavonoid and Fatty Acid by Efficient Enzymatic Esterification

Naringin is a flavonoid found in citrus fruits. It exhibits biological activities, such as anticancer and antioxidant effects, but it suffers from low solubility and low stability in lipophilic systems. These drawbacks lead to difficulties in the commercial application of naringin, but they can be overcome through esterification. In this study, naringin oleate was synthesized by enzymatic esterification and optimal conditions for the reaction were investigated. Experiments were conducted focusing on the following parameters: enzyme type, enzyme concentration, molar ratio of naringin to oleic acid, reaction temperature, and reaction solvent. We further confirmed the degree of esterification based on the difference in the initial and the final naringin concentrations. A conversion of 93.10% was obtained under optimized conditions (Lipozyme TL IM 10 g/L, molar ratio 1:20, reaction temperature 40 °C, acetonitrile as solvent, and 48 h reaction time). Thus, naringin oleate, a high value-added material that overcomes the low hydrophobicity of naringin and enhances its performance, was obtained through esterification of naringin using oleic acid. This study presented a method for the efficient enzymatic synthesis that could ensure high conversion within a shorter reaction time compared with that required in previously reported methods