Healable and Recyclable Polymeric Materials with High Mechanical Robustness

Abstract

The huge consumption and rapid expansion of polymeric materials in the world have caused pervasive environmental pollution and severe waste of material resources, urging the development of sustainable substitutes that are repeatedly healable and recyclable. In the past two decades, significant progress has been made in the development of healable and recyclable polymers based on the reversible noncovalent and/or dynamic covalent cross-linking of polymer chains. This Perspective focuses on the achievements on the mechanically robust dynamically cross-linked polymers with healability and recyclability. The strategies for the reinforcement of healable/recyclable polymers are highlighted, considering that the dynamically cross-linked polymers generally exhibit low mechanical robustness. The robust dynamically cross-linked polymers that are healable/recyclable upon heating and under mild conditions are also summarized. The emerging applications of the robust healable and recyclable polymers are further demonstrated. Outlooks are also provided to envision the remaining challenges for the further development and practical applications of healable and recyclable polymeric materials.

Mechanically Robust Dual-Crosslinking Elastomer Enabled by a Facile Self-Crosslinking Approach

“…The structures of the SCDCEs were characterized by Fourier transform infrared spectroscopy (FTIR). It can be found that the SCDCEs samples exhibit several characteristic peaks: the absorption peaks at 3350 cm −1 and 3180 cm −1 indicate the presence of N-H stretching vibration [ 22 , 23 , 24 ]; the peak at 1680 cm −1 can be attributed to the C=O stretching vibration [ 23 , 24 ]; the absorption peak at 1200 cm −1 can be assigned to the Si-O-Si bonds [ 25 ]. To verify that the methoxy groups of MEMO are cross-linked to form Si-O-Si bonds, the Raman spectrum of SCDCEs was obtained ( Figure 2 b).…”

Noncovalently Cross-Linked Polymeric Materials Reinforced by Well-Designed In Situ-Formed Nanofillers

“…As an extension of supramolecular polymers, reversibly cross-linked polymers have been widely and conveniently fabricated by cross-linking polymers based on noncovalent interactions and dynamic covalent bonds. − Originating from the plentiful reversible interaction groups on their chains, polymers have been shown to be very suitable for the construction of three-dimensional (3D) reversibly cross-linked networks, endowing noncovalently cross-linked polymers with superior mechanical properties compared to supramolecular polymers composed of small molecular monomers. − ,− Moreover, noncovalently cross-linked polymers also have the distinctive advantage of mass production. In 2010, Bowman et al first defined reversibly cross-linked polymeric networks based on dynamic covalent bonds as covalent adaptable networks (CANs) .…”

Mechanochromic and thermally reprocessable thermosets for autonomic damage reporting and self-healing coatings

“…With increased interest in sustainability and environmental responsibility, dynamic and exchangeable chemical reactions have been investigated for developing reprocessable thermosets known as covalent adaptable networks (CANs) [5][6][7][8] . This type of polymer behaves like a classical thermoset under ambient conditions, but the network topology can be rearranged repeatedly in response to external stimuli.…”