“Metallophilic crosslinking” to provide fast-curing and mendable poly(urethane-metallothiolate) elastomers

Abstract

INTRODUCTIONSince their discovery by Otto Bayer in 1937, polyurethanes (PUs) are widely used in many industrial applications. So far, one of the most common strategies for the fabrication of PU networks is the crosslinking of liquid polymer precursors to give a three-dimensional network. Such systems can be monocomponent, which cure by the reaction of isocyanate-terminated polymers with ambient moisture, or bicomponent, where isocyanate groups react with polyols. The wide use of PUs in many different specific applications is boosting the constant search for alternative materials with tailored properties, such as poly(urea-urethanes), polyureas, or polythiourethanes. 1 Here, we describe a novel two-component PU system based on a thiolterminated PU polymer and a silver salt, which permits a very fast-curing process. In addition, the resulting elastomeric material presents good processability at mild conditions.

Recyclable polybutadiene elastomer based on dynamic imine bond

“…In the past few decades, dynamic chemistry has aroused great research interest because of its reversible nature . There are two categories in dynamic chemistry: noncovalent interactions and dynamic covalent bonds . The dynamic interactions can be broken and reformed under certain external stimulus and have been incorporated into polymers to acquire reprocessing and recycling properties.…”

Dynamic cross-links to facilitate recyclable polybutadiene elastomer with excellent toughness and stretchability

“…In current days, developing eco‐friendly recyclable polymers is becoming an increasingly crucial issue for energy saving and environmental protection. Many methods for the fabrication of recyclable cross‐linked polymers have been reported, including using dynamic covalent chemistry or non‐covalent interactions . These cross‐links can reversibly rupture and reform under external stimuli, thereby allowing the easily processing and recycling.…”

“…Many methods for the fabrication of recyclable cross-linked polymers have been reported, including using dynamic covalent chemistry [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] or non-covalent interactions. [22][23][24][25][26][27][28][29] These cross-links can reversibly rupture and reform under external stimuli, thereby allowing the easily processing and recycling.…”

Preparation of recyclable polybutadiene rubber based on acid–base complexation

“…Due to the irreversible covalent crosslinking, the common rubbers usually can hardly be recycled at the end of their life time. [1][2][3][4] In the last decade, a variety of reversible covalent bonds, such as Diels-Alder reaction, [5][6][7] disulfide bond, 8 and imine bond, [9][10][11] as well as noncovalent interactions, like hydrogen bonding, [12][13][14] ionic interaction, [15][16][17][18] and metal-ligand bond, 19 have been utilized to prepare recyclable materials. These dynamic crosslinks can undergo reversible rupture and reformation upon external stimuli, enabling the as-formed materials to be reprocessed and recycled in the assistance of heat or solvent.…”