Improvement of wood properties by impregnation with multifunctional monomers

Abstract
Southern pine samples with different dimensions and bulk densities were impregnated with the multifunctional monomer ethyl α‐hydroxymethylacrylate (EHMA) and 5 mol % of fluorinated or nonfluorinated crosslinking agent. The maximum impregnation yield (105% by weight) was achieved under vacuum with good improvement of water repellency.Impregnation with EHMA plus another multifunctional monomer 2‐vinyl‐4,4‐dimethyl‐2‐oxazolin‐5‐one (vinyl azlactone) was carried out to improve the mechanical properties of wood samples. Water repellency was also improved depending on the amount of vinyl azlactone in the monomer solution. A maximum of 41% antiswell efficiency (ASE) was obtained by impregnation with a 9 : 1 w/w mixture of EHMA and vinyl azlactone. Improvements of 38–54% in impact strength and 27–44% in compression modulus were achieved depending on the relative amount of vinyl azlactone incorporated. FT‐IR and solution or solid‐state NMR spectroscopy were used for chemical characterization of the polymers themselves and the wood‐polymer composites.