Self‐healing polyurethane based on disulfide bond and hydrogen bond

Abstract

Tough and transparent polyurethane networks with self-healing capability at mild temperature conditions were successfully prepared in a 1-pot procedure. The self-healing ability of synthesized polyurethane comes from the covalent disulfide metathesis and non-covalent H-bonding.The mechanical testing indicates that disulfide metathesis reforms the covalent bonds on a longer time scale, while H-bonding gives rise to a healing efficiency of around 46% in the early healing processing. The compromise between mechanical performance and healing capability is reached by tailoring the concentration of disulfide. The tensile strength of the sample with 100% self-heal efficiency can get to 5.01 MPa, which can be explained by higher mobility of polymer chain under ambient temperature from creep testing. In order to increase the tensile strength of self-healing elastomer, the hydrogen bonding effect received attention. H-bonding is a kind of noncovalent self-healing trending force; the supermolecular selfhealing elastomer based on H-bonding interaction was firstly developed by Leibler and colleagues. 16,17 Other researchers also have similar reports. 18,19 Although the self-healing effect of H-bonding is limited, the contribution to the self-healing cannot be ignored.This work focuses on obtaining a material with good mechanical properties and self-healing in 1-pot method by adapting the disulfide concentration. The self-healing contribution of disulfide metathesis and H-bonding effect of this system were investigated. To the best of our knowledge, disulfide self-healing assisted H-bonding selfhealing materials have not been systematically studied.2 | EXPERIMENTAL | MaterialsPolytetramethylene ether glycol (PTMEG) with a number average molecular weight of 2000 g·mol −1 was provided by Aladdin IndustrialCorporation and was degassed for more than 3 hours at 90°C.

Self‐Healing Polycaprolactone Networks through Thermo‐Induced Reversible Disulfide Bond Formation

“…However, a majority of self-healing PCL materials based on UPy and DA bonds were suffering with low healing efficiency (about 60%) under mild temperature and short healing time (less than 2 h) condition due to low activity of UPy and DA bonds at mild temperature. Disulfide bonds have been introduced into epoxy networks [15,16] and polyurethane networks [17][18][19] to form high healing efficiency materials at mild temperature. In this work, we aim to introduce disulfide bonds into PCL networks to obtain a fast-rate self-healing capability under mild conditions.Here, a novel disulfide monomer (1) was synthesized by esterification with the existence of carbodiimide as an activator at room temperature (Scheme 1a).…”

Effect of the conversion degree and multiple healing on the healing efficiency of a thermally reversible self‐healing polymer

“…In recent decades, a substantial effort has been made with the aim of finding effective ways to heal these cracks. Synthesizing a polymer being able to recover its mechanical properties and mitigate damages under certain mechanisms is one of the methods that have been employed in many studies . Several approaches have been proposed for designing these types of materials, which can be classified under two major categories, namely, extrinsic and intrinsic.…”

“…Synthesizing a polymer being able to recover its mechanical properties and mitigate damages under certain mechanisms is one of the methods that have been employed in many studies. [1][2][3][4][5][6][7][8] Several approaches have been proposed for designing these types of materials, which can be classified under two major categories, namely, extrinsic and intrinsic. In the former, recovery occurs through embedding healing agents into the host material, while in the latter, it operates via macromolecules themselves.…”

A Robust and High Self‐Healing Efficiency Poly(Urea‐Urethane) Based on Disulfide Bonds with Cost‐Effective Strategy

“…However, to the best of our knowledge, the disulfide‐containing chain extenders used in the related studies were purchased directly and the prices were very expensive, such as bis(2‐hydroxyethyl) disulfide, bis(4‐aminophenyl)disulfide, and bis(4‐hydroxyphenyl) disulfide, which limited further applications in practice of scientific study and production. It is still a challenge to develop a low‐cost chain extender by simple and fast route containing disulfide bonds for the preparation of self‐healing poly(urea‐urethane).…”