Andrzej M. Krzysik

Guayule as a wood preservative

Conventional wood preservatives used to protect wood from insect and microbial damage are presently of major concern to human health and the environment. Finding alternative and economical preservatives has not been successful. Studies have shown that the resin material extracted from the guayule plant (Parthenium argentatum, Gray) has both insect and microbial resistant properties. Unfortunately, this finding has not been applied commercially. However, large quantities of guayule waste wood and resin material could become available with the domestication of guayule to produce hypoallergenic rubber latex. Thus, opportunities exist in using this natural source of biologically resistant resinous chemicals. The objective of this preliminary study was to determine the effects of latex-extracted wood residues or bagasse and resin extracts on termite and decay resistance properties of wood products. Two types of test materials were used. One was wood impregnated with organic solvent-extracted resin material from the plant. The other was composite board fabricated using the bagasse residue or whole plant and a plastic binder, which was used to improve the physical properties of the composite. Accelerated laboratory tests were conducted to determine the resistance of the wood products against an Eastern subterranean termite and wood fungi (brown-rot). The wood and stem of the guayule plant, wood treated with the resin extract, and particle and composite boards made from ground guayule bagasse exhibited termite and wood fungal resistance. Because the guayule plant is drought tolerant and its product can reduce the need to harvest trees for replacing wood damage, its cultivation as an alternative crop will help conserve water and forest resources world-wide.

Industrial Application of Animal Manure Filled Thermoplastics

Animal agriculture is under increasing pressure to produce more and more meat, milk and eggs giving rise to an increasing amount of manures. In the past, manures have been viewed as a waste byproduct used mainly as a fertilizer that has a value of 2 to 4 cents per dry pound. We need to change our view of manures from waste to asset. Destroying manures by burning or lagooning may solve the environmental problem but it does nothing to add to animal income. One of the alternatives is to use animal manures in industrial products. Based on past research at the Forest Products Laboratory in the area of wood and agricultural flours and fibers as fillers in thermoplastics, this research program uses swine and cow manures as reinforcing fillers in HDPE and HDPP. This is a win-win situation as it increases the value of the animal manures, decreases the cost and improves mechanical properties of the thermoplastic composites. A 40% blend of dry swine manure with HDPE and 2% MAPE gives a composite with MOE in bending of 1.31 GPa and MOR of 34.7 MPa as compared to unfilled HDPE MOE of 0.75 GPa and MOR of 15.1 MPa. A 40% blend of dry dairy manure with HDPE and 2% MAPE gives a composite gives MOE in bending of 2.18 GPa and MOR 21.9 MPa as compared to 40% pine flour with 2% MAPE MOE 2.98 and MOR 33.4 MPa.