A high stiffness and self-healable polyurethane based on disulfide bonds and hydrogen bonding

Abstract

Despite lots of strategies involving extrinsic and intrinsic solutions to self-healing materials, it remains a challenge to achieve a self-healable material with excellent mechanical properties. Here, we describe the use of poly(vinyl alcohol)-graft-(ε-caprolactone) cured isocyanate-terminated disulfide-containing polyurethane to tune the strength and self-healing efficiencies. The results of solvent swelling experiments and Fourier transform infrared spectrometer indicate crosslinking structure and numerous hydrogen bonds in our synthetic polymers. The strong hydrogen bonding interactions and appropriate crosslinked networks provide good tensile mechanical performance. Meanwhile, the dynamic disulfide bonds and hydrogen bonds in this system also enjoyably contribute to the self-healable behavior at a moderate temperature. The self-healing polyurethane displays a maximum Young’s moduli of 112 MPa, a toughness value of 81 MJ/m3, which are quite remarkable compared to the previous reports. The self-repairing efficiency is impressively as high as 94%. Moreover, this material also exhibits an attractive reprocessing ability.