Influences of extractives on the photodegradation of wood

Wood is susceptible to photodegradation when exposed to light. In addition to three main components of wood, the influence of extractives on photodegradation is not fully understood. This study examines the role of wood extractives in photodegradation process, and so the variations in the surface properties of non-extracted and extracted Cryptomeria japonica and Acacia confusa heartwood were examined after exposure to ultraviolet light. FTIR and UV-visible techniques were used to analyze the variations in chemical characteristics on the wood surfaces after irradiation. Following the lightfastness test, the contents of quinonoids and carbonyl groups derived from the lignin increased. However, the wood surface deteriorated less when the extractives existed. In conclusion, extractives play an essential role in the photodegradation of wood, and the rate of wood degradation was lessened by the presence of extractives.