ABSTRACT:The rubberwood samples were treated with 0.5-10% maleic anhydride (MA) solutions. The treatment of wood with 2.5% MA was adequate to prevent the growth of moulds on wood for 1 year at least. The viable count of Aspergillus niger van Tieghem PSU1 on MA treated wood indicated that fungal spores were not killed. The maleic anhydride treated wood slices had no antifungal activity. The concentration of MA released from treated wood in the leachate was 0.02 mg·m -3 . Agar well diffusion showed that the leachate from MA treated wood had no antifungal activity. However, after leaching MA treated wood still had a high resistance to mould growth. The moisture contents of MA treated and untreated wood samples were not significantly different. The MA treated wood showed almost a smooth surface while the untreated wood showed a rough surface. The cytotoxicity test showed that the leachates of both MA treated and untreated wood samples had a similar effect. So the treatment of rubberwood with MA is a safe method to prevent mould growth.

The aim of this study was to determine the efficacy of chitosan and methoxysilane in the prevention of surface mold growth on rubberwood. Three different chitosan samples were tested; C1 (Mw 37 kDa), C2 (Mw 5.4 kDa) and C3 (Mw 3.5 kDa). Radial growth inhibition assay of the chitosan samples was investigated at concentrations ranging from 0.063 to 0.5 %w/v against Aspergillus niger BAM 4 and Penicillium decumbens CBS 121928. Chitosan samples C1 and C3 exhibited strong antifungal activity against both molds. Rubberwood samples were either vacuum or dip treated with varying concentrations of chitosan or silane solution. The content of chitosan in wood showed that after the leaching test, chitosan was well retained in both vacuum and dip treated wood. The concentration of silicon in wood showed similar results. The vacuum treated wood samples with chitosan C1 and C3 at 1 %w/v concentration had strong resistance against A. niger BAM 4. However, dip treated rubberwood samples with 2 %w/v chitosan solutions showed lower resistance against A. niger BAM 4. On the other hand, both vacuum and dip treated rubberwood samples with chitosan had no resistance against P. decumbens CBS 121928. The silane treated wood samples showed no resistance to fungal growth.