A polymer-nanocellulose-lignin composite as disclosed comprises a polymer, nanocellulose, and lignin, wherein lignin forms a hydrophobic interface between the polymer and the nanocellulose. In some variations, a process is disclosed for producing a polymer-nanocellulose-lignin composite material, comprising: fractionating lignocellulosic biomass in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein lignin deposits onto fiber surfaces or into fiber pores; mechanically treating the cellulose-rich solids to form a hydrophobic nanocellulose material comprising cellulose fibrils and/or cellulose crystals; hydrolyzing the hemicellulose to generate fermentable hemicellulosic sugars; fermenting the fermentable hemicellulosic sugars to generate a monomer or monomer precursor; polymerizing the monomer to produce a polymer; and combining the polymer with the lignin-coated nanocellulose to generate a polymer-nanocellulose-lignin composite material for use in a wide variety of products.

A powder of modified cellulose fibers has an average fiber length of 1 m or more and 500 m or less, wherein the modified cellulose fibers are made from anionically modified cellulose fibers introduced at an anionic group with a modifying group. A dispersion contains a powder of modified cellulose fibers as defined above and a medium, wherein the powder of modified cellulose fibers is dispersed in the medium. A resin composition contains a powder of modified cellulose fibers as defined above and a resin, wherein the powder of modified cellulose fibers and the resin are blended. A resin molded article is obtained by molding a resin composition as defined above. A powder of cellulose fibers having excellent dispersibility in a solvent, which can be obtained by an inexpensive process, and a method for producing the same can be provided.

A method of manufacturing a fine cellulose fiber dispersion liquid includes: an oxidation process in which a cellulose is subjected to an oxidation treatment to obtain an oxidized cellulose; and a dispersion process in which the oxidized cellulose obtained in the oxidation process is subjected to a dispersion treatment in a water-based medium in which a pH thereof is adjusted to 4 to 12 using either an ammonia water or an organic alkali to obtain the fine cellulose fiber dispersion liquid.

A method for preparing a cellulose dispersion includes oxidizing cellulose; preparing cellulose nanofibers by defibrating the oxidized cellulose; and adding a water-soluble polymer and inorganic particles to the dispersion containing the cellulose nanofibers.

A cellulose particle having a length of from 1,000 to 10,000 nm and an aspect ratio of from 2 to 18 and a method for preparing cellulose particles including hydrolysing a cellulose material to provide hydrolysed cellulose particles, washing the hydrolysed cellulose particles, and fractioning the hydrolysed cellulose particles using differential centrifugation. A material includes the cellulose particles such as a film or cluster, a composition includes the cellulose particles or material including cellulose particles, and the use of the particles or materials in a composition. The particles may be used as white pigments, whiteness enhancers, scattering enhancers or opacifiers, due to their ability to provide excellent diffuse whiteness and opacity.

A method of manufacturing a fine cellulose fiber dispersion liquid includes: an oxidation process in which a cellulose is subjected to an oxidation treatment to obtain an oxidized cellulose; and a dispersion process in which the oxidized cellulose obtained in the oxidation process is subjected to a dispersion treatment in a water-based medium in which a pH thereof is adjusted to 4 to 12 using either an ammonia water or an organic alkali to obtain the fine cellulose fiber dispersion liquid.

This cellulose powder has: an average degree of polymerization of 100 to 350; a weight average particle size of over 30 m, but less than 250 m; an apparent specific volume of 2 to less than 15 cm.sup.3/g; and a particle size distribution sharpness of 1.5 to 2.9.

A process for dissolving modified cellulose is disclosed. The process includes contacting modified cellulose with a solvent in a mixture to form swelled modified cellulose and then contacting the mixture with a salt to dissolve the swelled modified cellulose.

A process for dissolving modified cellulose includes contacting modified cellulose solution with at least one multivalent cation to form a plurality of modified cellulose particles.

A method for preparing a cellulose dispersion includes oxidizing cellulose; preparing cellulose nanofibers by defibrating the oxidized cellulose; and adding a water-soluble polymer and inorganic particles to the dispersion containing the cellulose nanofibers.