Modification mechanism of plantation wood via grafting epoxy monomers onto cell walls

The range of application for fast-growing plantation wood is limited by its dimensional instability, susceptibility to biodegradation and low mechanical strength. In this study, a novel method based on in situ reaction of a hydrophilic epoxy monomer (1,4-butanediol diglycidyl ether) in the wood cell walls was proposed to improve the performance of plantation wood. The effects of curing agent on the reaction mechanism and performance of treated wood were discussed in detail. The results demonstrated that after curing using methyl hexahydro phthalic anhydride (MHHPA), an epoxy oligomer with a higher molecular weight and superior water resistance was formed inside the wood cell wall compared to curing with the 2-methylimidazole (2-MI). Moreover, the epoxy group was able to react with alcohol and phenolic hydroxyl in wood through 2-MI catalysis resulting in a higher grafting ratio. After the modification reaction, notable improvements were observed in the dimensional stability (anti-swelling efficiency of more than 65%), fungal ( Gloeophyllum trabeum ) decay resistance (weight loss of < 6%) and compressive strength (increased by 17%) of the wood.