Method for producing cellulose nanofibers

    公开(公告)号:US11713360B2

    公开(公告)日:2023-08-01

    申请号:US16607870

    申请日:2018-06-01

    IPC分类号: C08B15/04 C08B15/02 C08B15/00

    CPC分类号: C08B15/04 C08B15/02 C08B15/00

    摘要: An object of the present invention is to provide an efficient method for producing cellulose nanofibers, without N-oxyl compounds such as TEMPO remaining in the cellulose nanofibers. Provided is a method for producing cellulose nanofibers, the method including: oxidizing a cellulose raw material with hypochlorous acid, or a salt thereof, having an available chlorine concentration of from 14% by mass to 43% by mass, to produce an oxidized cellulose; and fibrillating the oxidized cellulose into nanofibers.

    Grafted crosslinked cellulose
    7.
    发明授权

    公开(公告)号:US11591429B2

    公开(公告)日:2023-02-28

    申请号:US17241421

    申请日:2021-04-27

    摘要: 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·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.

    SULFATE ESTER MODIFIED CELLULOSE NANOFIBERS AND METHOD FOR PRODUCING CELLULOSE NANOFIBERS

    公开(公告)号:US20230054106A1

    公开(公告)日:2023-02-23

    申请号:US17956990

    申请日:2022-09-30

    IPC分类号: C08B5/14 C08B7/00 C08B15/00

    摘要: Sulfate ester modified cellulose nanofibers having an average fiber diameter in the range of 1 nm to 500 nm, and having sulfate ester modified hydroxyl groups on surfaces of the cellulose nanofibers. A method of producing cellulose nanofibers that are nanosized, that have a high crystallinity degree, and that have large aspect ratios, the method being a chemical method that does not require any physical pulverization, that is energy-saving, and that can be performed under mild reaction conditions. A method of producing modified cellulose nanofibers including modifying the surfaces of the cellulose nanofibers through esterification or urethanization. A method of producing cellulose nanofibers includes impregnating cellulose with a fibrillation solution containing dimethylsulfoxide, at least one carboxylic acid anhydride selected from acetic anhydride and propionic anhydride, and sulfuric acid to fibrillate the cellulose.