Influence of Water and Humidity on Wood Modification with Lactic Acid

Impregnation of dry wood with pure lactic acid oligomers(OLAs)followed by heat treatment confers promising properties to wood because of OLA’s good diffusion,in-situ polymerization and persistence in cell walls.Treatment provides drastic reduction of the equilibrium moisture content,high dimensional stability and good durability.The presence of water during treatment has been evaluated.Curing of OLA impregnated dry wood in humid atmosphere leads to a strong and global degradation of the material.OLA treatment of wet wood only impacts the water leaching rate negatively.Treatment of dry wood with OLA diluted in water additionally decreases the biological resistance and is not efficient for decreasing hygroscopicity.Treatment of dry wood with lactic acid solution leads to a lower polymerization level but confers good properties.

ESR TECHNOLOGY-AN EFFECTIVE METHOD FOR RESEARCHING WOOD SURFACE MODIFICATION

The paper uses Chinese linden velnner as samples, and uses ESR technlology to ex amine the free radical concentration change during the process of wood surface moditication. This is a cffective method, and it can give proper evaluation about the extent and the quality of surface modification.

Prognostication of Wood Properties Alteration with Modification and Impregnation

The effects of wood roughness, modification and sanding on the water contact angle values of pine spruce and aspen wood surfaces were evaluated. Contact angle values set by time linear part extrapolation give increased values in comparison with ones obtained after water drop spreading on the surface. Water drop side-view contact angle along wood fiber directions is less influenced by surface roughness. Wood water activity （aw） can be used to ascertain available water content on surface.

Improvement of wood properties by composite of diatomite and “phenol-melamine-formaldehyde” co-condensed resin

We improved the overall performance of fast-growing poplar by utilizing a low-cost, effective and simple method. The fast-growing poplar was modified by a vacuum-pressure impregnation method with three types of modification solutions composed of phe- nol-melamine-formaldehyde （PMF） co-condensed resin, diatomite, and 3-aminopropyl （diethoxy） methylsilane. We measured the weight percent gain （WPG）, bulking, leaching, anti-swelling efficiency （ASE）, wa- ter-repellent effectiveness （WRE）, and oxygen index of the modified specimens. All of the wood physical properties, which are beneficial for human uses, were significantly improved by the treatment. We improved various characteristics of wood and the oxygen index of poplar above 48.6% after the modification using diatomite and PMF co-condensed resin.

Nanotechnology approaches towards biodeterioration-resistant wood:A review

Wood can be a suitable alternative to energy-intensive materials in various applications.Nev-ertheless,its susceptibility to weathering and decay has significantly hindered the broad adop-tion of the most commercially significant wood species.While current solutions do tackle certain challenges,they often come with disadvantages like high costs,environmental risks,and/or in-efficiencies.Nanotechnology-based methods can be employed to mitigate these weaknesses and create durable,sustainable wood materials.In this review,we delve into cutting-edge advance-ments in the development of biodeterioration-resistant wood through innovative nanotechnol-ogy approaches.These methods usually involve the application of nanomaterials,either pos-sessing biocidal properties or serving as carriers for biocides.We systematically describe these approaches and compare them to conventional wood modification methods.Additionally,this re-view provides a brief overview of the prevalent biodeteriorating organisms and their mechanisms of action,which notably impact the development and choice of a suitable strategy for wood mod-ification/treatment.Given the requirements of biodeteriorating organisms for growth and wood degradation,it is expected that the new nanotechnology-based approaches to enhance wood dura-bility may provide innovative broad-spectrum biocidal nanosystems.These systems can simulta-neously induce alterations in the physicochemical properties of wood,thereby constraining the availability of the growth requirements.These alterations can efficiently inhibit the biodeterio-ration process by decreasing water absorption,restricting access to the wood components,and reducing void spaces within the wood structure.Finally,this review highlights the new oppor-tunities,challenges,and perspectives of nanotechnology methods for biodeterioration-resistant wood,through which some techno-economic,environmental and safety aspects associated with these methods are addressed.