Enhancing interface adhesion between waterjet-produced rubber powders and natural rubber by wet-mixing method

The addition of rubber powder (RP) to natural rubber (NR) matrix using the dry mixing method leads to uneven distribution and poor interface bonding while the wet mixing method is not feasible due to the hydrophobic nature of the RP surface. To address this issue, we developed a method for producing RP with weakened hydrophobicity on the surface by high-pressure waterjet and successfully achieved even distribution of the waterjet-produced rubber powders (WPRPs) in NR and strong interface adhesion between WPRPs and NR by the wet mixing method. The properties of NR/WPRP composites were tested and characterized carefully. When adding 6 phr of 140-mesh WPRPs in the NR matrix, the tensile strength and elongation at break of the NR/WPRP composites were 30.2 MPa and 627.2%, respectively, which were 4% and 7% higher than NR without WPRPs. Moreover, the anti-abrasion property of the NR/WPRP composite was also strengthened by the addition of WPRPs. Our findings demonstrate that recycling waste rubber through a reasonable recycling method can not only reduce material waste and alleviate environmental pollution but also enhance the performance of the raw rubber, which offers significant economic benefits. Reducing the particle size of waterjet-produced rubber powders can enhance the interfacial bonding strength between the rubber powders and natural rubber. image