Mercury lamp-Induced Aging Effects on Surface Properties and Microstructure of Four Rosewood Species

This study investigated the effects of mercury lamp-induced aging on the surface properties and microstructure of four rosewood species ( Dalbergia retusa , Dalbergia bariensis , Pterocarpus macrocarpus , and Pterocarpus erinaceus ). Changes in wood color, gloss, roughness, chemical composition, and microscopic morphology during the aging process were systematically analyzed through simulated ultraviolet light-accelerated aging experiments conducted at 60°C for up to 720 hours. The results indicated significant differences in UV radiation responses among the species: Dalbergia retusa and Dalbergia bariensis demonstrated high photostability, attributed to their abundant antioxidant extracts, exhibiting minimal color changes (ΔE ≤ 3.18) and limited roughness increases (34.57–35.26%). In contrast, Pterocarpus macrocarpus and Pterocarpus erinaceus displayed notable color fading (ΔE = 4.58) and a 76.06% rise in roughness due to lignin photooxidation and extractive degradation. Fourier-transform infrared (FTIR) spectroscopy revealed chemical alterations, including lignin degradation and carbonyl formation, while environmental scanning electron microscopy (ESEM) observations identified microstructural deterioration, such as catheter wall cracking and crystalline deposition post-aging. The study elucidated the relationship between the photoaging mechanisms and the chemical composition and microstructure of rosewood, offering a scientific foundation for material selection, maintenance, and durability enhancement of rosewood furniture.