Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Electrophoresis-derived skim natural rubber dry rubber (ECSNR) was prepared and used to partially replace natural rubber in tire bead apex composites. The incorporation of 25 phr ECSNR significantly improved the 100% modulus while maintaining tensile strength, offering a sustainable strategy for bead apex rubber reinforcement.

ABSTRACT
In the current industrial practice, skim natural rubber latex (SNRL) is usually coagulated with strong acids to produce skim natural rubber (SNR) for recovery and reuse. However, strong acid coagulation generates large volumes of wastewater, causing environmental pollution and requiring strict treatment before discharge. To address this issue, this study proposed a green SNR preparation method based on electrophoresis. Electrophoresis skim rubber (ECSNR) was compared with SNR prepared by traditional strong acid or metal salt coagulation, and its application in bead apex rubber composites was investigated. FTIR and XRF results showed that ECSNR contained higher contents of non-rubber components, such as proteins and phospholipids. TGA results indicated that ECSNR had lower ash content and improved thermal stability. Compared with bead apex rubber composites prepared from conventional natural rubber, BAC-NR/ECSNR prepared by partially replacing natural rubber with ECSNR showed a 20.25% increase in 100% modulus and a 1.59% improvement in thermo-oxidative aging resistance, while the tensile strength did not decrease significantly. The electrophoretic preparation process proposed in this study does not require the addition of coagulants such as strong acids or metal salts, reducing the environmental damage caused during SNR preparation and realizing the high-value application of SNR in rubber products.