Supramolecular Polydimethylsiloxane Elastomer with Enhanced Mechanical Properties and Self-Healing Ability Engineered by Synergetic Dynamic Bonds

Li, J (Li, Jian) 1, 2Niu, HY (Niu, Hongyao) 1, 2Yu, YF (Yu, Yingfeng) 1, 2Gao, YL (Gao, Yulei) 1, 2Wu, Q (Wu, Qiang) 1, 2Wang, FF (Wang, Fenfen) 1, 2Sun, PCA (Sun, Pingchuan) 1, 2, 3

ACS APPLIED POLYMER MATERIALS, 2021, 3(7): 3373-3382

DOI 10.1021/acsapm.1c00271

Abstract

Hydrophobic elastomers are required for use in industry and daily life because of their versatile properties. Developing a hydrophobic elastomer with self-healing abilities and excellent mechanical performance has been very challenging because of the mutually exclusive nature of these properties. Herein, supramolecular polydimethylsiloxane (PDMS) elastomers with excellent self-healing and mechanical properties were designed through the synergetic combination of multistrength H-bonds and disulfide bonds. The hierarchical H-bonds formed with urethane, urea, and 2-ureido-4[1H]-pyrimidinone (UPy) moieties in the backbone of the supramolecular polymer endow the resultant polymers with effective reversible cross-linking, whereas during stretching, the dynamic dissociation and reassociation of H-bonds enable polymers with high extensibility and enhanced toughness and recoverability. In addition, disulfide bond exchange under heat enables polymer network rearrangement, thus imbuing the supramolecular elastomer with excellent self-healing ability. Based on the extraordinary properties of hydrophobic supramolecular PDMS elastomers, some smart materials can be prepared, such as oil/water separation foams and hydrophobic hot-melt adhesives. Therefore, this concept of synergetic dynamic bonds will point out a direction for the development of sustainable, green, and functional materials of the next generation.

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