An investigation of the potential for chemical modification and subsequent polymeric grafting as a means of protecting wood against photodegradation

Pine sapwood samples were chemically modified with methacrylic anhydride, and the modified samples were grafted with styrene via a free radical process. Unmodified, modified, and modified and styrene grafted samples were exposed to UV irradiation and the samples were then analysed for colour, brightness, and chemical changes (using infra-red and X-ray photoelectron spectroscopy). Although modification did impart colour stability to samples following UV exposure, there was no evidence that either modification, or modification plus grafting resulted in any improvement in the chemical stability of the wood. The colour stabilisation is attributed to the production of peroxy derivatives of the bonded acyl groups.