NANOCELLULOSE-DISPERSION CONCENTRATES AND MASTERBATCHES, METHODS OF MAKING AND USING THE SAME, AND NANOCELLULOSE-CONTAINING COMPOSITES
The disclosed technology provides improved compositions and methods for dispersion and drying of nanocellulose, for polymer composites and other systems. Some variations provide a nanocellulose-dispersion concentrate comprising nanocellulose and a dispersion/drying agent selected for compatibility with the nanocellulose and with the nanocellulose-containing composite product, wherein the dispersion/drying agent is selected from the group consisting of waxes, polyolefins, olefin-maleic anhydride copolymers, olefin-acrylic acid copolymers, polyols, fatty acids, fatty alcohols, polyol-glyceride esters, polydimethylsiloxanes, polydimethylsiloxane-alkyl esters, polyacrylamides, starches, cellulose derivatives, particulates, and combinations or reaction products thereof, and wherein the nanocellulose-dispersion concentrate is in solid form (e.g., a powder) or liquid form. Other variations provide a nanocellulose-dispersion masterbatch (e.g., pellets) comprising the nanocellulose-dispersion concentrate and a carrier material. Other variations provide a nanocellulose-containing composite including the nanocellulose-dispersion masterbatch or concentrate and a matrix material. Processes of making and using the disclosed compositions are described.
1 . A nanocellulose-dispersion concentrate comprising:
(a) from about 5 wt % to about 90 wt % nanocellulose, wherein said nanocellulose is a mixture of lignin-coated cellulose nanocrystals and lignin-coated cellulose nanofibrils; and
(b) from about 5 wt % to about 95 wt % dispersion/drying agent selected for compatibility with said nanocellulose,
wherein said dispersion/drying agent is selected from the group consisting of waxes, polyolefins, olefin-maleic anhydride copolymers, olefin-acrylic acid copolymers, polyols, fatty acids, fatty alcohols, polyol-glyceride esters, polydimethylsiloxanes, polydimethylsiloxane-alkyl esters, polyacrylamides, starches, particulates, and combinations or reaction products thereof,
and wherein said nanocellulose-dispersion concentrate is in solid form or liquid form.
2 . The nanocellulose-dispersion concentrate of claim 1 , wherein said nanocellulose is present at a concentration of about 10 wt % to about 70 wt %, and wherein said dispersion/drying agent is present at a concentration of about 5 wt % to about 50 wt %.
3 . The nanocellulose-dispersion concentrate of claim 1 , wherein said weight ratio of said nanocellulose to said dispersion/drying agent is selected from about 0.5 to about 2.
4 . The nanocellulose-dispersion concentrate of claim 1 , wherein said nanocellulose-dispersion concentrate consists essentially of said nanocellulose and said dispersion/drying agent.
5 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent is a functionalized polyalkylene wax that is functionalized for compatibility with said nanocellulose.
6 . The nanocellulose-dispersion concentrate of claim 5 , wherein said functionalized polyalkylene wax is a functionalized polyethylene wax, a functionalized polypropylene wax, a functionalized polybutylene wax, or a combination thereof.
7 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent is a low-molecular weight oligomer or polymer of ethylene or functionalized ethylene, with number-average degree of polymerization from 2 to 1000.
8 . The nanocellulose-dispersion concentrate of claim 7 , wherein said number-average degree of polymerization is from 5 to 500.
9 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent is a copolymer of (a) one or more C 2 -C 4 olefins and (b) maleic anhydride.
10 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent is a copolymer of (a) one or more C 2 -C 4 olefins and (b) acrylic acid.
11 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent includes a polyol selected from ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, butylene glycol, polybutylene glycol, or a combination thereof, wherein said polyol is optionally esterified with a fatty acid.
12 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent includes an alkyl ester polydimethylsiloxane emulsion.
13 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent includes cationic starch, amphoteric starch, thermoplastic starch, or a combination thereof.
14 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent includes a particulate selected from the group consisting of clay, nano-clay, talc, wollastonite, calcium carbonate, silica, mica, kaolin, nickel, glass fibers, bentonite, biotite, illite, kaolin, vermiculite, zeolite, carbon fibers, carbon nanotubes, graphene, or a combination thereof, and wherein said particulate optionally has a surface charge.
15 . The nanocellulose-dispersion concentrate of claim 1 , wherein said dispersion/drying agent includes at least one fatty acid and at least one particulate.
16 . The nanocellulose-dispersion concentrate of claim 1 , wherein said nanocellulose-dispersion concentrate further comprises a liquid solvent, and wherein said liquid solvent is optionally selected from the group consisting of water, C 1 -C 8 alcohols, C 2 -C 8 polyols, and combinations thereof.
17 . The nanocellulose-dispersion concentrate of claim 1 , wherein said nanocellulose-dispersion concentrate further comprises from about 0.1 wt % to about 50 wt % of one or more elastomers.