Strong Thermo‐Tolerant Urushiol Glycidyl Ether‐Crosslinked Acrylic Pressure‐Sensitive Adhesive

ABSTRACT Conventional acrylate pressure‐sensitive adhesives (PSAs) often soften, melt, or lose tackiness under high‐temperature conditions, leading to performance failure. To address this challenge, we exploited the molecular structural advantages of natural urushiol to design and synthesize a bio‐based crosslinker, urushiol glycidyl ether (UGE). Through the ring‐opening esterification reaction between the epoxy groups of UGE and the carboxyl groups of acrylic acid (AA), a three‐dimensional crosslinking network was constructed within the acrylate PSA matrix. By modulating the AA‐to‐UGE molar ratio, we systematically investigated the effect of crosslinking density on adhesive performance, heat resistance, and rheological behavior. The optimized formulation (PSA‐A1‐U1) exhibited a 180° peel strength of 8.34 N/24 mm, an initial tack level of 6, and a tack retention time exceeding 72 h. After preconditioning at 150°C for 2 h, no adhesive residue was observed, and the SAFT (shear adhesion failure temperature) exceeded 225°C. This work demonstrates a novel strategy for designing heat‐resistant, high‐performance PSAs and broadens the application prospects of natural urushiol derivatives in functional polymers.