Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Schematic diagram of the self-healing process of EVM via dynamic chemical crosslinking.

ABSTRACT
In practice, rubbers should be vulcanized to achieve serviceable performance. However, the current vulcanization methods still have some problems, including slow vulcanization rate and difficulty recyclability of waste rubbers, which hinder the sustainable development of rubbers. To address this issue, a dual crosslinking strategy that combines β-hydroxy ester bonds and disulfide bonds is employed to obtain rubbers with self-healing and reprocessability. Ethylene-vinyl acetate-glycidyl methacrylate terpolymer (EVM-GMA) is crosslinked by using 3′3-dithiodipropionic acid (DTPA), obtaining β-hydroxy ester crosslinks. The addition of carbon black can improve the mechanical properties of EVM-GMA composites. Compared with EVM-GMA/carbon black (100/40) composite crosslinked by peroxide, EVM-GMA/carbon black (100/40) composite crosslinked by DTPA exhibits a shorter positive vulcanization time (t
90 = 9.12 min), higher tensile strength (21.9 MPa), and self-healing. After two reprocessing cycles, the tensile strength of EVM-GMA/carbon black (100/40) composite can still reach 15.3 MPa, and the elongation at break is 365%. This study provides an effective approach for developing EVM-GMA composites with self-healing and reprocessable.