Strength Tests on Acetylated Aspen Flakeboards Exposed to a Brown-Rot Fungus
Keywords:Chemical modification, acetylation, flakeboard, aspen, strength, fungi, mechanical properties
AbstractAspen flakeboards made from control flakes and acetylated flakes at 18% acetyl weight gain using phenol-formaldehyde or isocyanate adhesives were subjected to a bending creep test under progressive brown-rot fungal attack with Tyromyces palustris. Deflection of the boards was measured as a function of time until failure. Isocyanate-bonded control flakeboards failed in an average of 26 days, while isocyanate-bonded acetylated boards showed little deflection after 100 days in test. Average weight loss of isocyanate-bonded control boards at failure averaged 6.2%, while the acetylated boards showed about 1.0% weight loss at the end of 100 days. Phenol-formaldehyde-bonded control flakeboards failed in an average of 76 days, while acetylated boards showed little deflection after 100 days in test. Average weight loss of phenol-formaldehyde-bonded control boards at failure averaged 8.6%, while the acetylated boards showed no weight loss after 100 days.
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