An object of the present invention is to provide a flame-retardant woody material having low hygroscopicity and excellent flame-retardant performance, and a flame retardant for woody materials therefor. The present invention relates to a flame retardant for woody materials comprising an organic phosphorus compound represented by the following formula (1) and a nitrogen compound represented by the following formula (2); and also relates to a flame-retardant woody material comprising a woody material fireproofed with the flame retardant for woody materials:

##STR00001## wherein in the formula (1), R.sub.1 and R.sub.2 are the same or different, and each represents a hydrogen atom, hydroxy, or the like; n is an integer of 1 to 4; X.sub.1 and X.sub.2 are the same or different, and each represents a hydrogen atom, hydroxy, or the like; and

##STR00002## wherein in the formula (2), R.sub.3, R.sub.4, R.sub.5, R.sub.6, and R.sub.7 are the same or different, and each represents a hydrogen atom, methyl, or the like.

Disclosed is a process for the acetylation of wood. The wood to be acetylated is first subjected to an extraction step. The resulting extracted wood particularly has a reduced hemicellulose content. This extracted wood is subjected to contact with an acetylation agent. The extraction can be done with an extraction fluid which is, e.g., water, acetone, ethanol, methanol, or acetic acid. The water can be pure water, such as tap water or demineralised water, or it can be a dilute salt solutions (e.g. water containing ammonium oxalate or sodium sulphite). Hot water extraction is preferred. The resulting acetylated extracted wood, particularly wood elements, have a desirable swelling behaviour at lower acetyl contents than conventional acetylated wood. The wood can be in the form of wood elements, solid wood, or wood veneers.

Highly transparent (up to 92% light transmittance) wood composites have been developed. The process of fabricating the transparent wood composites includes lignin removal followed by index-matching polymer infiltration resulted in fabrication of the transparent wood composites with preserved naturally aligned nanoscale fibers. The thickness of the transparent wood composite can be tailored by controlling the thickness of the initial wood substrate. The optical transmittance can be tailored by selecting infiltrating polymers with different refractive indices. The transparent wood composites have a range of applications in biodegradable electronics, optoelectronics, as well as structural and energy efficient building materials. By coating the transparent wood composite layer on the surface of GaAs thin film solar cell, an 18% enhancement in the overall energy conversion efficiency has been attained.

The present disclosure provides a method for preparing a piezoresistive sensor material, including: preparing a wood fiber aerogel; conducting dopamine self-polymerization on the surface of the aerogel to obtain a wood fiber-based hydrogel; soaking the wood fiber-based hydrogel in a nano conductive phase suspension or a nano conductive phase precursor to form a conductive phase-loaded wood fiber-based hydrogel; subjecting the conductive phase-loaded wood fiber-based hydrogel to reaction with an aqueous solution including a polyelectrolyte monomer, a crosslinker, an initiator and a catalyst to form a conductive phase-wood fiber-based hydrogel composite; and complexing the composite with metal ions. The present disclosure further discloses a piezoresistive sensor including the sensor material, and a preparation method thereof. The sensor material prepared by the method of the present disclosure has excellent mechanical strength and ionic conductivity, and a sensor further prepared has extremely-high sensitivity.

A process for treating lignocellulosic pieces with a water-soluble lignocellulosic material preservative. The process comprises the step of contacting the lignocellulosic pieces with a water-based preservative solution having a contact temperature between about 70 C. and about 95 C., the water-based preservative solution containing the water-soluble lignocellulosic material preservative in a concentration above about 25% wt. A lignocellulosic treatment apparatus for treating lignocellulosic pieces is also provided.

Systems and methods for treating wood products are provided. The methods comprise preconditioning the wood product by irradiating one or more surfaces of the wood product with infrared (IR) and/or ultraviolet (UV) radiation and subsequently treating the wood product. The systems comprise one or more fixtures positioned to irradiate one or more surfaces of the wood product with IR and/or UV radiation, wherein each fixture comprises a reflector and a radiation source.

The present invention relates to a process for preparing a modified wood product wherein the wood is treated with low-molecular weight resin based on lignin degradation products. The present invention also relates to a modified wood product produced using said process.

Methods for treating cellulosic materials comprising introducing a liquid treating composition into the cellulosic material, the treating composition comprising a solution prepared from at least: (i) one or more of a copper amine complex or copper ammine complex, such as copper tetraamine carbonate, (ii) one or more of ammonia or a water-soluble amine and (iii) water; and exposing the cellulosic material provided thereby to carbon dioxide and/or carbonic acid to provide treated cellulosic material, and treated cellulosic materials prepared thereby.

Methods for treating cellulosic materials comprising introducing a liquid treating composition into the cellulosic material, the treating composition comprising an aqueous alkaline copper-containing solution comprising copper tetraammine carbonate; and exposing the cellulosic material provided thereby to carbon dioxide to provide treated cellulosic material.

Wood preservative compositions comprising a particulate copper compound in a solvent carrier with low aromatic content. Particulate copper dispersions in this composition demonstrated superior stability, and wood treated with the composition is protected from attack by wood decay fungi and termites. The invention is also directed to wood preservative compositions comprising: (a.) a biodegradable organic solvent carrier selected from the group consisting of vegetable oil, renewable resource oil, and biodiesel; (b.) a dispersion of solid particles of a metal compound having a particle size between about 0.005 microns to about 10 microns; (c.) an organic biocide; and (d.) a dispersant; ratio of the dispersant to the metal compound is from about 1:500 to about 100:1 (wt/wt). The invention is also directed to compositions comprising penflufen and solvent carriers. The invention is also directed to methods of treating wood using the compositions, and wood treated with the disclosed compositions and methods.