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

Abstract

CO₂-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 CO₂-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 CO₂-based PSAs from bio-based epoxides, providing a promising platform for the design of high-performance biodegradable PSAs.