Pectin-wood shaving composite for filling wormholes in decorative paintings of historic wooden architecture

Wooden historical architecture is susceptible to wormhole damage due to prolonged exposure to biological factors, compromising the structural integrity and esthetic appearance. To address this issue, this study proposes a pectin-wood shaving composite with boron sodium oxide tetrahydrate (BSOT) and waterborne polyurethane (WP) as the filling material for the restoration of wormholes in wooden components. Accelerated hygrothermal degradation tests were performed under fluctuating temperature and relative humidity conditions, and the shrinkage rate, compressive strength, shear strength, bonding strength, color difference, and morphological characteristics were evaluated using scanning electron microscopy (SEM) and laser confocal microscopy (LCM). The experimental results indicated that the optimal composition of the filling material was 54 % wood shavings, 34 % pectin, 5 % WP, and 5 % BSOT. This composite material exhibited good dimensional stability, improved mechanical performance, weather resistance, antifungal properties, and compatibility with wood. The application of the pectin-wood shaving composite provides a novel approach to the restoration and preservation of similar structural damages in historic wooden architecture.