Investigations into the use of Maleic Anhydride/Sodium Hypophosphite as a Wood Modification Process
I Kim, D Jones, O Karlsson, D Sandberg, O N Antzutkin, F Ullah Shah
The formation of crosslinked bonds between wood constituents is believed to be an effective way to stabilize wood against wet conditions. The possibility to use maleic anhydride (MA) combined with sodium hypophosphite (SHP) as crosslinking agents was studied, using Scots pine sapwood and a model compound. The modified wood showed weight gain and bulking effect after treatment and subsequent Soxhlet extractions, which indicated penetration into the wood cell wall and reaction of the chemicals with the wood constituents. The FTIR spectra confirmed the formation of an ester bond between the wood and MA. Furthermore, a decrease of intensity of band at 1635 cm-1 indicated a reduction of the double bond between carbons in MA after further treatment with SHP, especially at 170 ̊C. Such reactions were studied using monomethyl maleate (MMM) and SHP. The 13C NMR spectra of the reaction product confirmed a reduction of the double bond between carbons. This paper outlines studies undertaken to date, along with outlining aims of ongoing and future work.