Surface chemical wood densification through in situ electron beam polymerization: description and dose study
J Triquet, P Blanchet, V Landry
Traditional wood chemical densification processes can be used to improve wood mechanical properties by increasing density of the material throughout its thickness. While mechanical surface densification has heavily been investigated, surface treatments involving impregnation of monomers remain unexplored. This study describes a new material, surface densified through lateral impregnation of acrylate monomers and their in-situ polymerization using high-energy electron beams. Yellow birch (Betula alleghaniensis, Britt.) was surface densified and its morphology was studied using X-Ray density profiles and microtomography. Brinell hardness of densified samples increased while irradiated controls showed lower hardness compared to untreated controls. Effect of electron beam dose was studied at 25, 50 and 100 kGy. Using acetone extraction and GC-MS, residual monomers were found at low dose while degradation of wood was observed ah higher dose using FT-IR. This study demonstrates how carefully choosing the electron beam dose impacts the material in different ways.
Keywords: densification, electron beam, acrylate, impregnation, hardness, extraction