Provided are NCC-based materials, as superb barrier materials for preventing oxygen and humidity from penetrating therethrough.

Provided are NCC-based materials, as superb barrier materials for preventing oxygen and humidity from penetrating therethrough.

Methods for the cross-metathesis of polysaccharides with one or more olefin-terminated side chains and cross-metathesized products are described. In an exemplary embodiment, a method for the synthesis of cellulose -carboxyesters via olefin cross-metathesis with acrylates is described. Conditions of the reactions were relatively mild and the olefin-substituted polysaccharides and the appropriate acrylate partners appear to follow Grubbs rules as summarized herein. Additionally, a method of hydrogenation of the cross-metathesized product is described. The compounds and methods may be useful for waterborne coating applications, adhesives, lubricants, or any product in need of dispersion in an aqueous media.

Methods for the cross-metathesis of polysaccharides with one or more olefin-terminated side chains and cross-metathesized products are described. In an exemplary embodiment, a method for the synthesis of cellulose -carboxyesters via olefin cross-metathesis with acrylates is described. Conditions of the reactions were relatively mild and the olefin-substituted polysaccharides and the appropriate acrylate partners appear to follow Grubbs rules as summarized herein. Additionally, a method of hydrogenation of the cross-metathesized product is described. The compounds and methods may be useful for waterborne coating applications, adhesives, lubricants, or any product in need of dispersion in an aqueous media.

The surface hydrophobization of cellulose nanocrystals (CNCs) by carboxylic acids, biodiesel, or plant oils was conducted via there herein disclosed green process using an one-pot synthetic method. In the process, an aqueous lactic acid syrup served as a solvent to provide a stable and well-dispersed water suspension of CNCs and participated in esterification reactions to produce an intermediate product of polylactic acid (PLA) oligomer grafted CNCs (CNC-g-PLA). This solvent and intermediate product system allows for an in situ solvent exchange from water to lactic acid without prior drying of the CNCs and a subsequent efficient esterification reaction of CNCs with carboxylic acids or esters having a long hydrocarbon chain (FAs). Another advantage of the disclosed process is the ability to reuse the reagents in the subsequent reaction in order to reduce the production cost. Grafting of renewable materials on the surface of CNCs was developed by polyesterification that is capable of being environmentally friendly and mass-produced without any organic solvents or toxic reagents.

The surface hydrophobization of cellulose nanocrystals (CNCs) by carboxylic acids, biodiesel, or plant oils was conducted via there herein disclosed green process using an one-pot synthetic method. In the process, an aqueous lactic acid syrup served as a solvent to provide a stable and well-dispersed water suspension of CNCs and participated in esterification reactions to produce an intermediate product of polylactic acid (PLA) oligomer grafted CNCs (CNC-g-PLA). This solvent and intermediate product system allows for an in situ solvent exchange from water to lactic acid without prior drying of the CNCs and a subsequent efficient esterification reaction of CNCs with carboxylic acids or esters having a long hydrocarbon chain (FAs). Another advantage of the disclosed process is the ability to reuse the reagents in the subsequent reaction in order to reduce the production cost. Grafting of renewable materials on the surface of CNCs was developed by polyesterification that is capable of being environmentally friendly and mass-produced without any organic solvents or toxic reagents.

Provided is a method of producing fine cellulose fibers that are nanosized, that have a high crystallinity degree, and that are less vulnerable to fiber shape damage, the method including impregnating cellulose with a fibrillation solution to fibrillate the cellulose without mechanical crushing, and modifying the cellulose. The method of producing cellulose microfibrils of the present invention includes impregnating cellulose with a fibrillation solution containing a carboxylic acid vinyl ester or an aldehyde and an aprotic solvent having a donor number of 26 or more to fibrillate the cellulose. The aldehyde is at least one kind of aldehyde selected from the group consisting of an aldehyde represented by the following formula (1), paraformaldehyde, cinnamaldehyde, perillaldehyde, vanillin, and glyoxal:

R.sup.1CHO(1)

where R.sup.1 represents a hydrogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group, a cycloalkyl group, or an aryl group.

The surface hydrophobization of cellulose nanocrystals (CNCs) by carboxylic acids, biodiesel, or plant oils was conducted via there herein disclosed green process using an one-pot synthetic method. In the process, an aqueous lactic acid syrup served as a solvent to provide a stable and well-dispersed water suspension of CNCs and participated in esterification reactions to produce an intermediate product of polylactic acid (PLA) oligomer grafted CNCs (CNC-g-PLA). This solvent and intermediate product system allows for an in situ solvent exchange from water to lactic acid without prior drying of the CNCs and a subsequent efficient esterification reaction of CNCs with carboxylic acids or esters having a long hydrocarbon chain (FAs). Another advantage of the disclosed process is the ability to reuse the reagents in the subsequent reaction in order to reduce the production cost. Grafting of renewable materials on the surface of CNCs was developed by polyesterification that is capable of being environmentally friendly and mass-produced without any organic solvents or toxic reagents.

The surface hydrophobization of cellulose nanocrystals (CNCs) by carboxylic acids, biodiesel, or plant oils was conducted via there herein disclosed green process using an one-pot synthetic method. In the process, an aqueous lactic acid syrup served as a solvent to provide a stable and well-dispersed water suspension of CNCs and participated in esterification reactions to produce an intermediate product of polylactic acid (PLA) oligomer grafted CNCs (CNC-g-PLA). This solvent and intermediate product system allows for an in situ solvent exchange from water to lactic acid without prior drying of the CNCs and a subsequent efficient esterification reaction of CNCs with carboxylic acids or esters having a long hydrocarbon chain (FAs). Another advantage of the disclosed process is the ability to reuse the reagents in the subsequent reaction in order to reduce the production cost. Grafting of renewable materials on the surface of CNCs was developed by polyesterification that is capable of being environmentally friendly and mass-produced without any organic solvents or toxic reagents.

Provided are NCC-based materials, as superb barrier materials for preventing oxygen and humidity from penetrating therethrough.