On the Welding of Vitrimers: Chemistry, Mechanics and Applications

Abstract

Linear chains in thermoplastics make them relatively weak in performance but inherently weldable and recyclable. By contrast, thermosets with permanently crosslinked networks possess outstanding mechanical performance, thermal, and chemical stability, but are unweldable and unrecyclable. In the last decade, a kind of thermoplastics‐like thermosets termed as vitrimer has been developed with extensive applications, in which welding of vitrimers plays a central and fundamental role. Herein, we present the current state of the art of the welding of vitrimers and discuss the welding of vitrimers from a broad picture of chemistry, physics, and mechanics: i) chemistry and mechanics of the welding of vitrimers; ii) applicability of the mechanical assessment methods for the welding of vitrimers; iii) design principles and implement strategies to the welding of vitrimers; iv) effects of welding conditions on the welding strength and toughness; and v) applications to the adhesion of chemically inert materials. Finally, advantages, challenges, and open questions to the welding of vitrimers are highlighted, and future opportunities in chemistry, mechanics, design of tough welding, artificial intelligence aided programming of welding technology, mechanical assessment standard, and so on are discussed. The development of vitrimer welding would fuse disciplines and make transformative impact in polymer industry.

Modeling Exchange Reactions in Covalent Adaptable Networks with Machine Learning Force Fields

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Low-Temperature Self-Healing Supramolecular Zinc-Poly(Urea–Urethane) Elastomer

“…In such an extreme environment, most elastomers are in, or close to the glassy state, which causes the occurrence of defects, such as microcracks and brittle fractures, resulting in critical safety accidents and considerable losses. 5,6 Self-repairing elastomers that perform at ultralow temperatures have recently proposed as a potential solution to the above-mentioned challenge. However, their applicability depends on two important factors: (1) they must comprise a molecular chain with high mobility (or a small moving unit inside it) 7−15 and (2) they must engage in highly active dynamic chemical bonds/interactions, typically via supramolecular interactions.…”

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“…The cured epoxy resin has excellent adhesion, heat resistance, dimensional stability, and mechanical properties. [1,2] The curing agents are of great importance to the properties of the cured epoxy resins. Common curing agents include amines, [3][4][5] acid anhydrides, [6][7][8][9][10] polyphenols, [11][12][13] polythiols, [14][15][16][17] and other modified curing agents.…”