Ultra-high-strength self-healing supramolecular polyurethane based on successive loose hydrogen-bonded hard segment structures

Abstract

Solving the weak toughness and strength of self-healing materials seems to be a mountain that is difficult to get over. Although some studies have reported high-strength self-healing materials, human intervention and long heal time are needed as compensation to self-heal. The balance between mechanical properties and self-healing efficiency is still challenging. Here, a high-strength self-healing supramolecular polyurethane is constructed based on a continuous loose hard segment structure. The polyurethane exhibits a maximum tensile strength greater than 45 MPa, maximum elongation at break of 850 %, and a tear strength of up to 118.776 KJ/m3, a self-healing efficiency of 95 %, which can effectively prolong the service life of the material. Strong soft segments and high-density loose hydrogen bond arrays are the source of strong mechanical strength. The asymmetric alicyclic loose hard segment structure ensures sufficient mobility of the molecular segments to complete hydrogen bond recombination in a short time. At the same time, its research as a conductive polymer matrix has been verified to restore 90 % of the conductivity, showing great application potential in the field of self-healing conductive composite material.