Decay Resistance Properties of Hemicellulose-Extracted Oriented Strand Board
C Howell, J Paredes, S Shaler, J Jellison
There is increasing interest in using cellulosic biomass as the basis for a renewable source of energy. Although the traditional focus has been on cellulose, researchers are also exploring the possibility of using hemicelluloses because they can be removed with hot water leaving the wood product intact for other applications. However, there is concern that removing hemicelluloses from the precursor material will create spaces in the wood increasing susceptibility to fungal attack.
Hemicellulose-extracted oriented strand boards (OSB) were created by exposing red maple strands to a hot water extraction prior to adhesive application and pressing. Treated and untreated boards were tested for decay susceptibility in a modified ASTM soil block jar bioassay using the white rot fungus Pycnoporus sanguineus and the brown rot fungus Meruliporia incrassata. There were no significant differences in weight losses for M. incrassata between hemicellulose extracted and untreated boards at the P = 0.01 level. Weight losses for P. sanguineus were significantly lower for hemicellulose extracted OSB compared to untreated controls.
These results indicate that modifying OSB panels by removing hemicelluloses for use in ethanol and other alternative fuel production does not increase decay susceptibility to M. incrassata and confers a degree of decay resistance against P. sanguineus. Additional testing is on-going.
Keywords: oriented strand board (OSB), hemicelluloses, decay resistance, white rot, brown rot, weight loss