Self‐Healing: Self‐Healing Polyurethanes with Shape Recovery (Adv. Funct. Mater. 33/2014)

Abstract

On page 5261, Heo and Sodano report new thermo‐responsive self‐healing polyurethanes that use the shape memory effect to bring the crack faces into intimate contact, such that healing can take place, thus eliminating the need for an external force to close the crack. The image shows the specimen before and after healing, demonstrating the reformation of the polymer, which can be done repeatably.

Ambient temperature induced Diels–Alder crosslinked networks based on controlled methacrylate copolymers for enhanced thermoreversibility and self-healability

“…Most of DA-crosslinked networks were fabricated through step-growth polyaddition or coupling reaction of polymaleimides and polyfurans. [48][49][50][51][52][53][54][55][56][57] Of our interests are thermo-labile networks based on reactive methacrylate copolymers. The nature of the polymethacrylate backbones of carbon-carbon single bonds, the high molecular weight of polymeric chains, and the facile copolymerization with so monomers allow for tuning the balance of rigidity and exibility of methacrylate networks.…”

Thermoresponsive crosslinked isocyanate‐free polyurethanes by Diels‐Alder polymerization

“…They are particularly used in adhesives and owing to the reactants, they exhibit various properties: from soft elastomers to rigid materials. In most of adhesive applications, irreversible crosslinked PU networks are used, therefore remendable PUs have been studied in literature …”

“…In most of adhesive applications, irreversible crosslinked PU networks are used, therefore remendable PUs have been studied in literature. [7][8][9][10] Generally PUs are synthesized by reaction between a di-or polyisocyanate and a mixture of short and long polyols. However, diisocyanates are harmful for human health and environment [11][12][13][14][15] ; therefore the studies on nonisocyanate polyurethanes (NIPUs) has recently gained an interest in both academic and industrial communities.…”

Remendable thermosetting polymers for isocyanate-free adhesives: a preliminary study

“…Indeed they are irreversibly cured into a highly cross-linked network giving an infusible and insoluble material. [7][8][9][10] The most efficient way to obtain remendable thermosets is to incorporate reversible bonds which can break on demand using proper stimulus. In response to this concern, remendable polymers have been widely studied over the last few decades.…”

“…Therefore many studies have been conducted on remendable PUs. [7][8][9][10] The most efficient way to obtain remendable thermosets is to incorporate reversible bonds which can break on demand using proper stimulus. Several stimuli are possible: temperature, radiation, pH, etc.…”