A gas separation membrane has a gas separation layer containing a cellulose resin, and an organopolysiloxane compound layer disposed on the gas separation layer in which Si ratio of the organopolysiloxane compound layer after immersion in chloroform to the organopolysiloxane compound layer before immersion in chloroform, the Si ratio being calculated by Mathematical expression (I), is 0.6 to 1.0.

Si ratio=(SiK X-ray intensity after immersion in chloroform)/(SiK X-ray intensity before immersion in chloroform)Mathematical expression (I)

An object is to provide a method for producing a polysaccharide derivative without using a catalyst, a cocatalyst, or an active compound by esterification, etherification, or the like, from a polysaccharide such as cellulose as a source material, while maintaining a high molecular weight. Another object is to provide a method for producing a cellulose derivative in a separated condition directly from biomass containing lignocellulose. A method for producing a polysaccharide derivative of the present invention is characterized in that a reaction is carried out in a mixture comprising: a source material comprising a polysaccharide; an ionic liquid for which the pKa of a conjugate acid of an anion in DMSO is 12 to 19 and which is capable of producing a carbene; and a chain or cyclic ester compound or an epoxy compound. Preferably as a source material containing a polysaccharide, a biomass source material containing lignocellulose is used.

In accordance with some embodiments of the present invention, a composite material is prepared by blending a flame retardant modified cellulosic nanomaterial (FR-CN) filler into a polymer, wherein the FR-CN filler comprises a cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs)) having a surface functionalized to incorporate a phosphorus-containing moiety. In some embodiments, the FR-CN filler is prepared by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a halogenated phosphorous-containing monomer (e.g., diphenyl phosphoryl chloride). In some embodiments, the surface of the cellulosic nanomaterial is further functionalized to incorporate an orthogonal functionality selected to enhance the compatibility of the FR-CN filler with the polymer by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a monomer (e.g., epichlorohydrin when the polymer is an epoxy-based polymer).

In accordance with some embodiments of the present invention, a composite material is prepared by blending a flame retardant modified cellulosic nanomaterial (FR-CN) filler into a polymer, wherein the FR-CN filler comprises a cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs)) having a surface functionalized to incorporate a phosphorus-containing moiety. In some embodiments, the FR-CN filler is prepared by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a halogenated phosphorous-containing monomer (e.g., diphenyl phosphoryl chloride). In some embodiments, the surface of the cellulosic nanomaterial is further functionalized to incorporate an orthogonal functionality selected to enhance the compatibility of the FR-CN filler with the polymer by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a monomer (e.g., epichlorohydrin when the polymer is an epoxy-based polymer).

A resin composition includes a cellulose derivative, wherein a Hazen color number (APHA) of the resin composition is 50 or lower.

A resin composition includes a cellulose derivative, wherein a Hazen color number (APHA) of the resin composition is 50 or lower.

In accordance with some embodiments of the present invention, a composite material is prepared by blending a flame retardant modified cellulosic nanomaterial (FR-CN) filler into a polymer, wherein the FR-CN filler comprises a cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs)) having a surface functionalized to incorporate a phosphorus-containing moiety. In some embodiments, the FR-CN filler is prepared by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a halogenated phosphorous-containing monomer (e.g., diphenyl phosphoryl chloride). In some embodiments, the surface of the cellulosic nanomaterial is further functionalized to incorporate an orthogonal functionality selected to enhance the compatibility of the FR-CN filler with the polymer by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a monomer (e.g., epichlorohydrin when the polymer is an epoxy-based polymer).

In accordance with some embodiments of the present invention, a composite material is prepared by blending a flame retardant modified cellulosic nanomaterial (FR-CN) filler into a polymer, wherein the FR-CN filler comprises a cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs)) having a surface functionalized to incorporate a phosphorus-containing moiety. In some embodiments, the FR-CN filler is prepared by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a halogenated phosphorous-containing monomer (e.g., diphenyl phosphoryl chloride). In some embodiments, the surface of the cellulosic nanomaterial is further functionalized to incorporate an orthogonal functionality selected to enhance the compatibility of the FR-CN filler with the polymer by reacting hydroxyl groups on the surface of the cellulosic nanomaterial and a monomer (e.g., epichlorohydrin when the polymer is an epoxy-based polymer).

Embodiments of the invention provide regioselectively substituted carbohydrate and polysaccharide derivatives, such as cellulose esters, and methods for preparing them. Particular methods of the invention include deacylation of esters using tetrabutylammonium fluoride to obtain selective substitution at desired hydroxyl position(s) of the ester. Preferred is deacylation of an ester, which shows selectivity for removal of acyl groups from the ester of the secondary alcohols at C-2 and C-3, and which affords cellulose-6-O-esters with high regioselectivity by a simple one-step process employing no protective groups. Inventive regioselectively substituted cellulose esters can be prepared by such methods to obtain esters with the following anhydroglucose repeating units: ##STR00001## wherein R.sup.1, R.sup.2, and R.sup.3 are each independently chosen from a hydrogen atom, and, whether substituted or unsubstituted, branched or unbranched, an alkanoyl group, an aroyl group, and a heteroaroyl group. In embodiments, the alkanoyl, aroyl and heteroaroyl groups can comprise from 1-20 carbon atoms.

Embodiments of the invention provide regioselectively substituted carbohydrate and polysaccharide derivatives, such as cellulose esters, and methods for preparing them. Particular methods of the invention include deacylation of esters using tetrabutylammonium fluoride to obtain selective substitution at desired hydroxyl position(s) of the ester. Preferred is deacylation of an ester, which shows selectivity for removal of acyl groups from the ester of the secondary alcohols at C-2 and C-3, and which affords cellulose-6-O-esters with high regioselectivity by a simple one-step process employing no protective groups. Inventive regioselectively substituted cellulose esters can be prepared by such methods to obtain esters with the following anhydroglucose repeating units: ##STR00001## wherein R.sup.1, R.sup.2, and R.sup.3 are each independently chosen from a hydrogen atom, and, whether substituted or unsubstituted, branched or unbranched, an alkanoyl group, an aroyl group, and a heteroaroyl group. In embodiments, the alkanoyl, aroyl and heteroaroyl groups can comprise from 1-20 carbon atoms.