The receptivity of powdered beech wood (Fagus crenata) to cyanuric chloride

Abstract

The chemical modification of powdered beech wood by reaction with cyanuric chloride (2,4,6-trichloro-s-triazine) is discussed in terms of the reaction time and temperature, as well as the concentration of the aqueous sodium hydroxide solutions used in the preparation of alkali-treated wood powders. The influence of the surface structure of wood on the receptivity of alkali-treated wood powders to this reagent is also discussed. The amount of cyanuric chloride taken up by the wood powder treated with the highest concentration of aqueous sodium hydroxide (18% NaOH) is about 0.8 mmol/g. This exceeds the theoretical amount of cyanuric chloride which can be reacted with the primary surface in the void model previously proposed. the extent of cross-linking at longer reaction times is minimal in case of the treatment of wood with 0.8% sodium hydroxide. On the other hand, the hydrolysis of C−Cl bonds of the second and third chlorine on the s-triazine ring and/or the internal cross-linking reactions are accelerated by increases in the concentration of sodium hydroxide. However, these reactions (the hydrolysis of C−Cl bonds and the internal cross-linking) are independent of the change in the structure of wood caused by the mercerizing alkalinity.