Hydrophobisation and densification of wood by different chemical treatments

Samples of Pinus sylvestris were treated with different reagents bearing isocyanate, carboxylic anhydride or oxirane functions to induce reaction with the OH groups of the various components of wood. Conditions were optimised to achieve maximum grafting. When the reagents also carried a polymerisable function, a monomer (styrene or methyl methacrylate) was incorporated into the wood morphology after the derivatisation reaction. Subsequent radical polymerisation produced chemical incorporation of some of the resulting macromolecules. The properties of the doubly modified samples were assessed using a wide variety of tests. Both the hydrophobic character and the density increased considerably, suggesting improved lifetime and extended domains of application.