There is little published scientific literature on the laboratory or field testing of wood-plastic composites (WPC) against termite attack. Therefore, the objective of this research was to investigate termite resistance (both laboratory and field) of 5 different extruded WPC blends of 50% western pine wood flour (WF) and high-density polyethylene (HDPE), and untreated pine solid wood. The study included two unmodified control WPC blends (one with cut surfaces and one with plastic rich surfaces); one blend with 3% coupling agent (maleated polyethylene, MAPE); one blend with acetylated WF; and one blend with 1% ZB. These 3 modifications/treatments were chosen because (1) coupling agents are known to promote bonding between the plastic and unmodified wood fibers when added to WPCs; (2) acetylating the wood esterifies the hydroxyl groups, making the wood more hydrophobic, dimensionally stable, and biologically durable; and (3) ZB is a known fungicide and insecticide used in some commercial WPC formulations. All WPC blends tested performed well (0.1% - 0.7% weight loss; 66% – 71% termite mortality) in the 10 week dry-wood laboratory termite test compared to the untreated solid wood (9.1% weight loss; 33.8% mortality.) Field exposure ratings are on a scale from 0 (complete failure) to 10 (sound, one to 2 small nibbles should be permitted.) After 30 months field exposure to Macrotermes gilvus Hagen in Bogor, Indonesia the acetylated WPCs performed the best with ratings of all 10s and only 0.8% weight loss, followed by the 1% ZB blend with ratings of all 9s and 3.9% weight loss. The coupling agent blend had ratings of all 8s and 13.6% weight loss, while the unmodified WPC controls had ratings of 7 and from 11.3-22.6% weight loss. The solid wood was completely destroyed with 100% weight loss and 0 rating.

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