Self‐Repairable Polyurethane Networks by Atmospheric Carbon Dioxide and Water

Abstract

Sugar moieties were incorporated into cross-linked polyurethane (PUR) networks in an effort to achieve self-repairing in the presence of atmospheric carbon dioxide (CO2) and water (H2O). When methyl-α-D-glucopyranoside (MGP) molecules are reacted with hexamethylene diisocyanate trimer (HDI) and polyethylene glycol (PEG) to form cross-linked MGP-polyurethane (PUR) networks, these materials are capable of self-repairing in air. This process requires atmospheric amounts of CO2 and H2O, thus resembling plant behavior of carbon fixation during the photosynthesis cycle. Molecular processes responsible for this unique self-repair process involve physical diffusion of cleaved network segments as well as the formation of carbonate and urethane linkages. Unlike plants, MGP-PUR networks require no photo-initiated reactions, and they are thus capable of repair in darkness under atmospheric conditions.

Dynamic covalent urea bonds and their potential for development of self-healing polymer materials

“…Endowing polymer materials with self-healing properties can solve this problem and meet sustainable development criteria. Up to now, repairable polymer systems have been realized with reversible 1 or irreversible 2,3 covalent bonds, supramolecular interactions, 4 chemo-mechanical features [5][6][7] and/or shape memory. [8][9][10][11] In addition, recent studies have also shown that van der Waals forces 12 as well as microphase separation 13 in thermoplastic polymers can also facilitate self-healing without elaborate chemical modications.…”

Structural effects on the reprocessability and stress relaxation of crosslinked polyhydroxyurethanes

“…Chemical recycling of crosslinked PUs has been explored as an effective approach to convert PUs into monomers or oligomeric molecules, but this approach is limited by the high energy requirements and multistep processing. Effective approaches for directly reprocessing crosslinked PUs have been developed, but most require specialized monomers containing other dynamic functional groups or have less desirable mechanical properties . Therefore, interest has arisen in controlling the dynamics of carbamate linkages themselves to enable reprocessing, inspired by seminal work on crosslinked PU stress relaxation by Offenbach and Tobolsky .…”

Tuning chain extender structure to prepare high-performance thermoplastic polyurethane elastomers

“…The crystallinities and morphology of these PUs were characterized by Differential Scanning Calorimeter (DSC), Small-Angle X-ray Scattering (SAXS), Wide-Angle X-ray Diffraction (WAXD), Polarizing Optical Microscope (POM) and Scanning Electron Microscopy (SEM). As a result, a highperformance thermoplastic polyurethane elastomer polymer have been synthesized by using 6,6 0 -bis [1-methyl-2-(b-hydroxyethyl)ester- …”

“…Therefore, there is a huge consumption of PUs in the global plastic application market at high growth rate. [2][3][4][5] Recently it also shows interesting applications in self-healing materials, [6][7][8] stimuliresponsive materials, [9][10][11][12] and exible conductive materials. 13 Meanwhile, concerns about the poor heat resistance of PUs limit their further applications.…”