The effect of silica modified by deep eutectic solvents on the properties of nature rubber/silica composites

The effect of deep eutectic solvent (DES) modified silica on the properties of nature rubber (NR) composites were investigated. The DES is an environment-friendly and low-cost solvent, which was prepared by mixing choline chloride and urea in a 1:2 molar ratio. The NR composites filled with DES modified silica were prepared and the properties were tested. The interaction between the DES and silica were characterized by Fourier transform infrared spectroscopy (FTIR), the interaction between silica and silica were tested by differential scanning calorimetry (DSC). The dynamic properties, such as rolling resistance and wet skid resistance, and were tested by dynamic mechanical analysis (DMA). Morphologies of the composites were characterized by scanning electron microscopy (SEM). The results indicate that the DES can interact with silica by hydrogen bond to improve the compatibility between the rubber and silica. When the content of DES was 3 phr, the tensile strength, modulus at 300%, tear strength, and the crosslinking density of the composites was increased. At the same time, the proper content of DES can reduce the rolling resistance of the vulcanized rubber while maintaining good wet skid resistance.