Influences of merbau heartwood extracts and their metal complexes on wood photodegradation

Abstract

Merbau (Intsia spp.) heartwood is a highly valued commercial wood but has problems with extractive bleeding when used as a construction material outdoors. The metal complexation method is one solution to resolve this problem. However, properties of merbau heartwood extracts would be modified and the anti-weathering ability changed. This study investigates the wood photo-protection ability of the merbau heartwood extract and its metal complexes. The results reveal that merbau heartwood extract has good free radical scavenging ability and UV absorptivity, which could inhibit wood photodegradation. After metal complexation, the extract-metal complexes also have wood photo-protection ability that inhibits wood photodegradation. Furthermore, since catecholic phenols were chelated by iron(II)/copper(II), the oxidative derivatives were consequently inhibited. Accordingly, these findings show that both merbau heartwood extract and its metal complexes have the ability to remove photo-induced hazards and enhance wood photostability for short periods of UV irradiation. Additionally, these results can be a reference for the environmentally benign utilization of merbau heartwood.