Dimensional stabilization of wood by chemical modification using isopropenyl acetate

N Giridhar,S.S Bisht,H.M Vagdevi,K.K Pandey,B.E Prasad

doi:10.4067/s0718-221x2017005000002

Abstract

Chemical modification of wood with isopropenyl acetate (IPA) using iodine (I2) as catalyst has been carried out. Rubber wood (Hevea brasiliensis) specimens were reacted with IPA using iodine (I2) catalyst at 95°C up to 10 h under solvent free conditions. The effect of catalyst concentration and reaction time was studied. The extent of acetylation was measured by determining weight percent gain and the modified wood was characterized by FTIR-ATR and 13C NMR spectroscopy. It was found that IPA in the presence of iodine is an excellent acylating reagent for wood. Modified wood exhibited high dimensional stability.

Highlights

Wood is hygroscopic, dimensionally unstable especially in high humidity environment and prone to biological decay due to fungus and other microorganisms (Rowell 1983, 2013)
The average weight percent gain (WPG) increased with increasing reaction time
Samples up to weight gains of 17 % were obtained using to 0,035 mol L-1 (I-2) of iodine

Summary

INTRODUCTION

Dimensionally unstable especially in high humidity environment and prone to biological decay due to fungus and other microorganisms (Rowell 1983, 2013). All the major cell wall constituents of wood (lignin, cellulose and hemi-celluloses) contain an abundance of free hydroxyl groups These free hydroxyl groups absorb and release water upon changes in the climatic conditions resulting in dimensional movements of wood. The dimensional stability and biological resistance of wood can be improved considerably by chemical modification by converting hydrophilic -OH groups of cell wall components into larger more hydrophobic groups by forming covalent bonds (Rowell 1983, 2013, Matsuda 1996, Hill 2006). Giridhar and Pandey (2016) reported chemical modification of wood by transesterification using IPA in presence of AlCl3 as catalyst and examined dimensional stability and UV resistance of modified wood.

MATERIALS AND METHODS

RESULTS AND DISCUSSIONS

CONCLUSIONS