Synthesis of Stimuli-Responsive, Deep Eutectic Solvent-Based Polymer Thermosets for Debondable Adhesives

Abstract

This paper demonstrates a macromolecular design for deep eutectic solvent (DES)-based polymer thermosets that are adhesive but removable on demand by depolymerization. For the design of a DES, a novel self-immolative polymerizable molecule capable of donating hydrogen bonds has been synthesized to form a room-temperature eutectic mixture when combined with another olefinic hydrogen bond acceptor. The physical properties of the liquid mixture have been characterized, and the mixture has been confirmed to be suitable for the formation of easily processable, resilient, transparent thermosets through click addition polymerization. The materials not only degrade on a molecular level as designed but also show interfacial adhesion onto various substrates, yielding a debondable polymer adhesive. The adhesive strength, which is comparable to that of commercial glue, decreases significantly in response to trace amounts of fluoride under benign conditions. As an example, after exposure to 0.01 M CsF, the bonded glass substrates easily separated within 16 h at room temperature. Similarly, the energy-efficient delamination of mixed composites was also achieved. We envisage that our design concept would benefit the development of functional polymeric materials that facilitate end-of-use processes.

3D-Printed Photocurable Resin with Synergistic Hydrogen Bonding Based on Deep Eutectic Solvent

“…Polymerizable DESs (PDESs) have been applied in various fields, including catalysis, energy, sensors, and biology. , Due to the presence of hydrogen-bonding acceptors and donors, the green functional PDESs can be used for syntheses with 100% atom utilization . Moreover, PDESs are easily synthesized with tunable properties and biocompatibility and have been used to fabricate 3D-printed elastomers. , However, additional applications based on 3D-printed PDES remain to be developed.…”

Synthesis of Renewable, Recyclable, Degradable Thermosets Endowed with Highly Branched Polymeric Structures and Reinforced with Carbon Fibers

“…The resulting functional composites can be degraded and recycled, and their shapes can be altered; the extent of each process can be controllable on command. We envisage that our concept promotes the design of thermosets with fully bio-based components and autonomous responses, − which can be further advanced by the embedment of other inorganic additives or biomolecules such as enzymes to achieve specific functions for target applications.…”

Green, Removable Adhesive Based on Graft Copolymers of Aliphatic Polyesters for Multiple Types of Substrates

“…Adhesives play an important role and are widely used in industries, such as aerospace, automobile manufacturing, civil engineering, and daily life . In recent years, recycling valuable adherends from waste products by debonding has attracted significant attention from not only the academia but also business circles for its fresh perspective of green chemistry and sustainability. − For traditional adhesives, they are chemically stable and usually have a strong interaction (covalent bonds, physical interactions, or their combinations) with the substrate surfaces. Therefore, debonding of the adhesive joints can only be conducted by thermal degradation, cutting, etc., which may inevitably lead to damage or even destroy the substrates.…”

“…5 and I 1.8 are the intensities of methylene groups with different chemical environments of the PVA backbone, and 0.01 is the D s of the COCH 3 group (calculated by the degree of hydrolysis of PVA-105). The average degree of polymerization (D p ) of PPDO graft chains was calculated as follows:…”