Acrylate Wood Densification: Effects of Vacuum Time and Nanoparticles on Chemical Retention, Penetration, and Resin Distribution
Keywords:
Nanoparticles, surface densification, density profile, chemical retention, morphologyAbstract
The feasibility of preparing a surface-densified wood product by replacing the traditional time-consuming pressurization stage with only a short vacuum time was investigated. Sugar maple and red oak wood specimens were successfully impregnated with low-viscosity resins of 1,6 hexanediol dimethacrylate and trimethylolpropane trimethacrylate, with or without silicate nanoparticles, using vacuum times of 30 s to 10 min without pressurization. Chemical retention (CR) and vertical density profiles of the treated wood specimens were measured. The CRs obtained with the short vacuum impregnation process, even with a vacuum of 30 s or 60 s, proved comparable to those achieved by the traditional process of 30-min vacuum plus 30-min pressure. A 52-63 wt% CR was found for maple impregnated with neat resin, while the formulations containing nanoparticles achieved 44-55 wt% as the vacuum time was increased 30 s to 10 min. Oak yielded lower CR values. The vertical density profiles indicated better treatability for maple than oak. Examination of the resin and resin/nanoparticle penetration into the wood by scanning electron microscopy revealed successful wood impregnation with both nanoparticles and resin.References
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