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.

Grafted, crosslinked cellulosic materials include cellulose fibers and polymer chains composed of at least one monoethylenically unsaturated acid group-containing monomer (such as acrylic acid) grafted thereto, in which one or more of said cellulose fibers and said polymer chains are crosslinked (such as by intra-fiber chain-to-chain crosslinks). Some of such materials are characterized by a wet bulk of about 10.0-17.0 cm3/g, an IPRP value of about 1000 to 7700 cm2/MPa.Math.sec, and/or a MAP value of about 7.0 to 38 cm H2O. Methods for producing such materials may include grafting polymer chains from a cellulosic substrate, followed by treating the grafted material with a crosslinking agent adapted to effect crosslinking of one or more of the cellulosic substrate or the polymer chains. Example crosslinking mechanisms include esterfication reactions, ionic reactions, and radical reactions, and example crosslinking agents include pentaerythritol, homopolymers of the graft species monomer, and hyperbranched polymers.

A process is provided for producing a biomass-derived rheology modifier, comprising: providing a pretreated feedstock comprising cellulose-rich solids; refining the cellulose-rich solids in a first high-intensity refining unit, generating refined cellulose solids; gelling the refined cellulose solids in a second high-intensity refining unit, thereby generating gelled cellulose solids; and homogenizing the gelled cellulose solids in a high-shear homogenizer, thereby generating a biomass-derived rheology modifier. The pretreated feedstock may include kraft pulp, sulfite pulp, AVAP® pulp, soda pulp, mechanical pulp, thermomechanical pulp, and/or chemimechanical pulp, derived from wood or lignocellulosic biomass. The pretreated feedstock may be GP3+® pulp, obtained from steam or hot-water extraction of lignocellulosic biomass. These rheology modifiers may be utilized in a wide variety of applications, including water-based or oil-based hydraulic fracturing fluid formulations, as gelling agents. These rheology modifiers are biodegradable, and their production does not directly involve chemicals other than biomass and water.

A process is provided for producing a biomass-derived rheology modifier, comprising: providing a pretreated feedstock comprising cellulose-rich solids; refining the cellulose-rich solids in a first high-intensity refining unit, generating refined cellulose solids; gelling the refined cellulose solids in a second high-intensity refining unit, thereby generating gelled cellulose solids; and homogenizing the gelled cellulose solids in a high-shear homogenizer, thereby generating a biomass-derived rheology modifier. The pretreated feedstock may include kraft pulp, sulfite pulp, AVAP® pulp, soda pulp, mechanical pulp, thermomechanical pulp, and/or chemimechanical pulp, derived from wood or lignocellulosic biomass. The pretreated feedstock may be GP3+® pulp, obtained from steam or hot-water extraction of lignocellulosic biomass. These rheology modifiers may be utilized in a wide variety of applications, including water-based or oil-based hydraulic fracturing fluid formulations, as gelling agents. These rheology modifiers are biodegradable, and their production does not directly involve chemicals other than biomass and water.

The present invention relates to a polymer composition comprising an anionic polymer composite having a synthesized polymer portion and a polysaccharide portion, obtainable by polymerizing vinyl monomers in the presence of the polysaccharide. The present invention further relates to a strength system and methods of production and use in providing a paper product.

Polymer conjugates are provided that are capable of mimicking functions of natural proteoglycans found in the extracellular matrix of connective tissues. The polymer conjugates of the invention have utility in treating a subject suffering soft tissue conditions. Also provided are simple and scalable chemical processes for the preparation of the polymer conjugates of the invention.

It is an object of the present invention to provide a fluffed cellulose having totally new properties that have not conventionally existed, and a cellulose fiber-containing material capable of realizing the same. The present invention relates to a cellulose fiber-containing material comprising cellulose fibers having anionic groups, wherein the yield of the cellulose fiber-containing material measured by the following measurement method is 50% by mass or more, the cellulose fiber-containing material has organic onium ions as counterions of the anionic groups, and the organic onium ions satisfy a predetermined condition.

The present invention provides novel hybrid polymers having unique physical properties. The hybrid polymers comprise a cellulose ether moiety, a linking group moiety, a spacer group moiety, and a lactam moiety. The present invention also provides compositions comprising the hybrid polymers and methods for preparing and using the hybrid polymers.

In a first embodiment, the hybrid polymers have the structure:

A-(L.sub.1-S—(B).sub.k).sub.q

wherein A is derived from a cellulose ether moiety comprising a —OH group; L.sub.1 is a linking group moiety selected from the group consisting of urethanes, amides, esters, carbonates, and phosphate esters, or is derived from a moiety selected from the group consisting of anhydrides, cyclic ethers, and aziridines; S is a spacer group moiety, selected from the group consisting of straight- or branched-chain functionalized and unfunctionalized alkyl, cycloalkyl, alkenyl, and aryl groups, wherein any of the above groups may be with or without heteroatoms, or is a direct bond; and B is a lactam moiety; wherein k≥1 and q≥1.

In a second embodiment, the hybrid polymers have the structure:

A-(L.sub.2-S—B).sub.y

wherein A is derived from a cellulose ether moiety comprising a —OH group; L.sub.2 is an ether linking group moiety; S is a spacer group moiety, selected from the group consisting of straight- or branched-chain functionalized and unfunctionalized alkyl, cycloalkyl, alkenyl, and aryl groups, wherein any of the above groups may be with or without heteroatoms, or is a direct bond; and B is a lactam moiety; wherein y≥1; with the proviso that when the cellulose ether moiety is hydroxyethyl cellulose, -(L.sub.2-S—B).sub.y is not derived from 1-(hydroxymethyl)-2-pyrrolidinone.

The present invention provides novel hybrid polymers having unique physical properties. The hybrid polymers comprise a cellulose ether moiety, a linking group moiety, a spacer group moiety, and a lactam moiety. The present invention also provides compositions comprising the hybrid polymers and methods for preparing and using the hybrid polymers.

In a first embodiment, the hybrid polymers have the structure:

A-(L.sub.1-S—(B).sub.k).sub.q

wherein A is derived from a cellulose ether moiety comprising a —OH group; L.sub.1 is a linking group moiety selected from the group consisting of urethanes, amides, esters, carbonates, and phosphate esters, or is derived from a moiety selected from the group consisting of anhydrides, cyclic ethers, and aziridines; S is a spacer group moiety, selected from the group consisting of straight- or branched-chain functionalized and unfunctionalized alkyl, cycloalkyl, alkenyl, and aryl groups, wherein any of the above groups may be with or without heteroatoms, or is a direct bond; and B is a lactam moiety; wherein k≥1 and q≥1.

In a second embodiment, the hybrid polymers have the structure:

A-(L.sub.2-S—B).sub.y

wherein A is derived from a cellulose ether moiety comprising a —OH group; L.sub.2 is an ether linking group moiety; S is a spacer group moiety, selected from the group consisting of straight- or branched-chain functionalized and unfunctionalized alkyl, cycloalkyl, alkenyl, and aryl groups, wherein any of the above groups may be with or without heteroatoms, or is a direct bond; and B is a lactam moiety; wherein y≥1; with the proviso that when the cellulose ether moiety is hydroxyethyl cellulose, -(L.sub.2-S—B).sub.y is not derived from 1-(hydroxymethyl)-2-pyrrolidinone.

Provided are a polylactide-grafted cellulose nanofiber that is suitable as a molding material, and a production method thereof. A polylactide-grafted cellulose nanofiber includes grafted cellulose having a graft chain bonding to cellulose constituting a cellulose nanofiber, wherein the graft chain is a polylactide, and a ratio of an absorbance derived from C═O of the polylactide to an absorbance derived from O—H of the cellulose on an infrared absorption spectrum is no less than 0.01 and no greater than 1,000. In addition, a production method of a polylactide-grafted cellulose nanofiber includes carrying out graft polymerization of a lactide to cellulose constituting a cellulose nanofiber in the presence of an organic polymerization catalyst which includes an amine and a salt obtained by reacting the amine with an acid. As the organic polymerization catalyst, 4-dimethylaminopyridine and 4-dimethylaminopyridinium triflate are preferred.