Reaction of Epoxides with Wood.
Forest Service research paper,
FOREST PRODUCTS LAB MADISON WI
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This report is a summary of an 8-year research program at the Forest Products Laboratory on chemical modification of wood with epoxides. Several species of wood were tested and the reactivity of many mono and difunctional epoxides was determined. The majority of the research concentrated on the reactions of propylene and butylene oxides catalyzed with triethylamine using southern pine. Low molecular weight epoxides react with wood cell wall polymer hydroxyl groups using a mild alkali catalyst. The chemicals penetrate the cell wall, reaction is fast, there are no byproducts generated with dry wood, and stable chemical bonds are formed. Because reaction takes place in the cell wall, the increase in wood volume from the treatment is proportional to the calculated volume of chemical added. Bulking of the wood, caused by bonded chemical, results in 50 to 70 percent dimensional stability at chemical weight gains of 20 to 30 percent. Above this level of treatment, the increase in added chemical causes the cell wall structure to break down and dimensional stability is lost. Good resistance to biological attack is observed in wood modified to levels of 20 to 30 weight percent gains in laboratory tests with brown and white-rot fungi, and with termites.
- Organic Chemistry
- Wood, Paper and Related Forestry Products