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 two-part flame-retardant, a flame-retardant oriented strand (OSB) and method for forming a flame-retardant OSB is provided. The two-part flame-retardant composition includes an aqueous solution containing a water-soluble flame-retardant and a flame-retardant powder that is incorporated into an oriented strand board without substantially affecting the mechanical properties of the oriented strand board. The method includes applying the aqueous solution containing a water-soluble flame-retardant to an oriented strand board furnish and applying a flame-retardant powder to the wetted furnish, without requiring an additional drying step.

The present invention relates to improved methods of treating wooden materials. By the method of the invention, the wooden material is subjected to vacuum, overpressure and increased temperature, and subjected to ultrasound. Ultrasound is applied while the wooden material is covered by a liquid at a suitable overpressure and at a suitable temperature for a suitable period of time.

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.

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.

The present disclosure describes a treated cellulosic material comprising a cellulosic material having a porous structure defining a plurality of pores, at least a portion of the pores containing a treating agent comprising a polymer, the polymer comprising a polyurethane polymer. The present disclosure further describes a method for preparing a treated cellulosic material comprising providing a cellulosic material; and a first treatment protocol comprising impregnating the cellulosic material with an aqueous dispersion comprising a polymer, the polymer comprising a polyurethane polymer; and a second treatment protocol comprising impregnating the cellulosic material with a modifying agent, the modifying agent comprising a hydrophobic amine.

A flexible structure is formed by subjecting cellulose-based natural wood material to a chemical treatment that partially removes hemicellulose and lignin therefrom. The treated wood has a unique 3-D porous structure with numerous channels, excellent biodegradability and biocompatibility, and improved flexibility as compared to the natural wood. By further modifying the treated wood, the structure can be adapted to particular applications. For example, nanoparticles, nanowires, carbon nanotubes, or any other coating or material can be added to the treated wood to form a hybrid structure. In some embodiments, open lumina with-in the structure can be at least partially filled with a non-wood substance, such as a flexible polymer, or with entangled cellulose nanofibers. The unique architecture and superior properties of the flexible wood allow for its use in various applications, such as, but not limited to, structural materials, solar thermal devices, flexible electronics, tissue engineering, thermal management, and energy storage.

The present invention relates to the creation of thermally insulating materials derived from cellulosic materials by selectively depolymerizing the materials anatomy. Cellulosic materials may be comprised of three main biopolymers: lignin, hemicellulose, and cellulose. The present invention relates to the chemical and physical removal of lignin and hemicellulose, while leaving the cellulose unaltered to induce increased porosity within the material and the material's macrostructure matrix for use as thermal and acoustic insulation. The increased porosity will be due to the creation of closed cell voids within the cellulosic matrix. These voids will increase the thermal and acoustic insulating performance of the cellulosic materials. The selective removal of secondary biopolymers from cellulosic materials allow for isolation of other value added products that can be regenerated through fewer reactions/steps. This is a novel advantage over other similar processes that dissolve cellulose completely, making it harder to extract and isolate secondary off-stream products.

The present disclosure describes a treated cellulosic material comprising a cellulosic material having a porous structure defining a plurality of pores, at least a portion of the pores containing a treating agent comprising a polymer comprising an olefin-carboxylic acid copolymer; and a modifying agent comprising an epoxy.

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.