Performance enhancement of bio-based rubber composites using epoxidized natural rubber for silica without carbon emissions and volatile organic compounds

Tire development tendency is green, environment-friendly, and safeguarding life and health. The conventional tires, consisting of solution polymerized styrene-butadiene rubbers (SSBR), silica, silane coupling agents, and other rubber additives, will not be able to keep up with the demand. SSBR, as a synthetic rubber processed from nonrenewable petroleum resources, creates a large amount of carbon emissions in the production process and the reaction between silica and silane coupling agents generates a large amount of volatile organic compounds (VOCs), which is detrimental to the environment and human health. In this article, epoxidized natural rubber (ENR) with different epoxide degrees was successfully prepared and blended with natural rubber (NR)/silica composites to improve the dispersion of silica and the performance of nanocomposites. The effect of heat treatment temperature on the reaction between ENR and silica and the dynamic and static mechanical properties of ENR/NR/silica nanocomposites was investigated by mechanical properties test, transmission electron microscopy, x-ray photoelectron spectroscopy, and Fourier transform infrared. The results showed that the epoxy groups on the ENR molecular chain could react with the silanol on the surface of silica to form a strong chemical bond, which improved the dispersion of silica in the rubber matrix and further enhanced the performance of the rubber composites without carbon emission and VOCs.