Preparation and Properties of Green Deep Eutectic Solvent-Modified Calcium Carbonate/Natural Rubber Composites

In order to reduce the reliance of rubber composites on carbon black (CB) and enhance their cost-effectiveness and environmental sustainability, this paper proposes a green, deep eutectic solvent (DES) for surface modification of ground calcium carbonate (GCC). It replaces part of the carbon black with the DES in a natural rubber matrix. The effects of this modification on the vulcanization, mechanical, dynamic and microstructural properties of rubber are systematically investigated. The DES employed consisted of choline chloride and glycerol in a 1:2 M ratio, with the aim of improving the interfacial bonding between GCC and the rubber matrix through the hydrogen bonding network. The results demonstrated that DES-modified GCC could effectively enhance the dispersion of filler, strengthen the crosslink density of rubber, and improve the mechanical properties. In the present study, the replacement of CB with 15 and 20 parts of GCC was investigated, with a particular focus on the tensile strength of the rubber composites prepared with DES-modified GCC in a 1:10 ratio. The results demonstrated a significant enhancement in tensile strength, with an increase of 16.0%, as well as a notable increase in the (TS*EB), reaching 22.6%. Additionally, a substantial reduction in rolling resistance of tyres was observed, amounting to 52.7%. These findings offer a novel approach for the development of environmentally friendly and cost-effective rubber fillers.