Self-healing Behavior of Ethylene Propylene Diene Rubbers Based on Ionic Association

• Published in: Chinese journal of polymer science 2019-07, Vol.37 (7), p.700-707
• Main Authors: Zhang, Zhi-Fei, Yang, Kun, Zhao, Shu-Gao, Guo, Lai-Na
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Crosslinking; Ethylene; Industrial Chemistry/Chemical Engineering; Mechanical properties; Polymer Sciences; Propylene; Rubber; Self healing materials; Smart materials; Vulcanization
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-019-2241-0

To meet the increasing demand for safe, environmentally friendly and high-performance smart materials, self-healing rubbers are highly desired. Here, the self-healing performance of ethylene propylene diene monomer rubber (EPDM) is reported, which was designed by graft-polymerization of zinc dimethacrylate (ZDMA) onto rubber chains to form a reversible ionic cross-linked network. Single ionic cross-linked network and dual network, combining covalent and ionic cross-links, could be tuned by controlling vulcanization process to achieve tailorable mechanical and self-healing properties. It was found that ionic cross-linked EPDM showed a recovery of more than 95% of the original mechanical strength through a healing process of 1 h at 100 °C. The covalent cross-links could improve mechanical properties but block self-healing. Adding 50 wt% liquid rubber to “dry” EPDM could effectively enhance self-healing capability of the dual cross-linked network and the healed tensile strength could reach 0.9 MPa. A compromise between mechanical performance and healing capability could be potentially tailored by controlling vulcanization process and liquid rubber content.