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.

A method for densifying a hygroscopic material is disclosed. The method is for hygroscopic material which may be a natural hygroscopic material or woodThe method comprises the steps of providing the hygroscopic material to be densified; pre-conditioning of the hygroscopic material by adjusting the moisture content of the hygroscopic material to a value within a predefined moisture range, if required; simultaneously heating and pressing the gas-tight packed hygroscopic material under predefined temperature and pressure conditions, whereby the moisture content of the hygroscopic material is kept constant; and obtaining a densified material.

A durable palm fiber composite material is obtained by impregnating an unprocessed palm bark in a resin adhesive solution prepared by using a palm leaf as a raw material and then hot-pressing. The palm bark is dried under a natural state without additional processing. The palm leaf is made into a tannin resin adhesive solution under the effect of additives such as furfuryl alcohol, paraformaldehyde, and others. A pH value of the adhesive solution is controlled to be 9-11. A solid content is 40-60%. An adhesive amount applied to the palm bark by the resin adhesive solution is 800-1500 g/m.sup.2. Odd number of layers (three or more layers) of palm barks that are impregnated by the resin adhesive solution and are hot-pressed to the composite material. Hot-pressed parameters are as follows: the temperature is 150-180 C. the unit pressure is 0.8-1.5 MPa, and the time is 10-30 s/mm.

A wood substrate or member is included, having an increased density with respect to natural, untreated wood. The process includes drying the wood prior to application of heat and pressure, which are controlled to reduce or eliminate color change on a surface of the wood member where heat and pressure are applied.

Alcoholic spirits may be artificially aged under highly pressurized carbon dioxide. The carbon dioxide may form carbonic acid, which may cause various esters to form in the presence of wood as well as to mellow the flavor when no wood is present. Wood may be pretreated with ozone, which may extract lignin which may further convert to vanillin during pressurized CO2 treatment, giving a vanilla note. After processing with pressurized CO2, a post-treatment of ozone may be given to the spirit, which may cause a mild oxidation and further mellowing of the spirit.

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.

Alcoholic spirits may be artificially aged under highly pressurized carbon dioxide. The carbon dioxide may form carbonic acid, which may cause various esters to form in the presence of wood as well as to mellow the flavor when no wood is present. Wood may be pretreated with ozone, which may extract lignin which may further convert to vanillin during pressurized CO2 treatment, giving a vanilla note. After processing with pressurized CO2, a post-treatment of ozone may be given to the spirit, which may cause a mild oxidation and further mellowing of the spirit.

A delignified wood material is formed by removing substantially all of the lignin from natural wood. The resulting delignified wood retains cellulose-based lumina of the natural wood, with nanofibers of the cellulose microfibrils being substantially aligned along a common direction. The unique microstructure and composition of the delignified wood can provide advantageous thermal insulation and mechanical properties, among other advantages described herein. The thermal and mechanical properties of the delignified wood material can be tailored by pressing or densifying the delignified wood, with increased densification yielding improved strength and thermal conductivity. The chemical composition of the delignified wood also offers unique optical properties that enable passive cooling under solar illumination.

A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various applications.