Enhancement of the hygrothermal ageing properties of gelatine films by ethylene glycol diglycidyl ether

Abstract Owing to the instability of gelatine in hygrothermal environments, gelatine-based cultural heritage undergo various deterioration processes, such as cracking, peeling, warping, curling and fracture, posing significant threats to its long-term preservation. Building on previous research, this study investigates the stability of polyol glycidyl ether–gelatine composite films under high-humidity and high-temperature conditions using ethylene glycol diglycidyl ether (EGDE) as a model compound. The hygrothermal ageing properties of EGDE–gelatine composite films are evaluated in terms of macrosize, mesoscopic structure, surface properties and mechanical properties. Results indicate that EGDE enhances the dimensional stability and swelling ratios of the composite films, stabilizes the pore structure and distribution and maintains the hydrophilicity and molecular structural stability under hygrothermal ageing conditions. Furthermore, the incorporation of EGDE leads to superior stress–strain properties of the composite films in such challenging environments. This study provides valuable experimental data for the preparation and conservation applications of gelatine-based cultural heritage materials.