Crosslinked CO2‐Based Polycarbonate: Biobased Pressure‐Sensitive Adhesives Combining Wettability and Cohesive Strength

CO 2 ‐based polycarbonates show great potential for application as biodegradable pressure‐sensitive adhesives (PSAs). However, it remains challenging for polycarbonate‐based PSAs to achieve rapid surface wetting while simultaneously maintaining sufficient cohesive strength. To address this issue and improve adhesive performance, we propose a strategy for preparing crosslinked polycarbonate PSAs. As a proof of concept, bio‐derived epoxides, including furfuryl glycidyl ether and n ‐butyl glycidyl ether, were introduced as key monomers to synthesize functionalized CO 2 ‐based polycarbonates (PBFCs). The crosslinked PSAs were subsequently constructed through a Diels–Alder reaction, while the flexible side chains enabled rapid wetting of the adhesive on the substrate surface. As a result, the static shear adhesion was significantly improved from approximately 0.1 h to over 24 h, accompanied by a tack grade of #2. Notably, the prepared PSAs could be reused for three cycles while maintaining a peel strength of approximately 2 N cm −1 , and no visible residue was observed on the substrate after peeling. This study develops a series of crosslinked CO 2 ‐based PSAs from bio‐based epoxides, providing a promising platform for the design of high‐performance biodegradable PSAs. CO 2 ‐based polycarbonates demonstrate significant potential in the application of biodegradable pressure‐sensitive adhesives (PSAs). However, achieving rapid surface wetting while maintaining sufficient cohesive strength remains a challenge for linear polycarbonates. To address these issues and enhance PSA performance, this study proposes a strategy for preparing crosslinked CO 2 ‐based polycarbonate PSAs. Polycarbonates (PBFC) were synthesized via the copolymerization of bio‐based glycidyl ethers (furfuryl glycidyl ether and n ‐butyl glycidyl ether) with carbon dioxide. Subsequently, the furan rings on the side chains of PBFCs reacted with bismaleimide hexane via Diels–Alder chemistry to form crosslinked PSAs, whereas the flexible side chains of PBFC facilitated rapid wetting of the substrate surface. Results demonstrated that the introduction of the crosslinked structure significantly enhanced the static shear adhesion force (increasing from approximately 0.1 h to over 24 h). Notably, the prepared PSAs could be reused three times while maintaining a peel strength of approximately 2 N/cm, with no residues observed on the substrate during peel tests. In this study, a series of crosslinked CO 2 ‐based PSAs were developed using bio‐based epoxides, providing a novel platform for the production of high‐performance biodegradable PSAs.