Cellulose foams for high performance insulations
AssigneeWashington State University
InventorsXiao Zhang, Aboutaleb Ameli, Peipei Wang
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Abstract
Environmentally friendly, sustainable, and high-performance ultralight composite foams are disclosed. The composite foams are prepared from cellulose nanomaterial, polymeric material, and a crosslinking agent. The fabrication process is simple and uses only water. The composite foams exhibit an elastic strain exceeding the values reported for known nanocellulose-based foams with no reinforcement. The foams exhibit a thermal conductivity superior to that of traditional insulating materials and retain structural integrity after burning.
Claims19
A composite foam, comprising:
- about 10 wt % to about 95 wt % of a cellulose component wherein said cellulose component is about 20 wt % to about 100 wt % cellulose nanomaterial;
- about 1 wt % to about 25 wt % of a water-soluble polymer comprising a plurality of first crosslinkable groups,
- about 1 wt % to about 25 wt % of a water-soluble crosslinking agent comprising a plurality of second crosslinkable groups;
- wherein at least a portion of the second crosslinkable groups are covalently bonded with at least a portion of the first crosslinkable groups and at least a portion of the hydroxy groups of the cellulose component;
- and
- wherein the composite foam has an apparent density of about 0.01 g/cm3 to about 0.25 g/cm3.
A method of making a composite foam, comprising freeze-casting or freeze-drying an aqueous composition comprising a foam precursor, wherein the foam precursor comprises:
- about 10 wt % to about 95 wt % of a cellulose component wherein said cellulose component is about 20 wt % to about 100 wt % cellulose nanomaterial;
- about 1 wt % to about 25 wt % of a water-soluble polymer comprising a plurality of first crosslinkable groups, about 1 wt % to about 25 wt % of a water-soluble crosslinking agent comprising a plurality of second crosslinkable groups;
- wherein at least a portion of the second crosslinkable groups can form covalent bonds with at least a portion of the first crosslinkable groups and at least a portion of the hydroxy groups of the cellulose component;
- and
- wherein the composite foam has an apparent density of about 0.01 g/cm3 to about 0.25 g/cm3.
A composite foam prepared by a method of making a composite foam, comprising freeze-casting or freeze-drying an aqueous composition comprising a foam precursor, wherein the foam precursor comprises:
- about 10 wt % to about 95 wt % of a cellulose component wherein said cellulose component is about 20 wt % to about 100 wt % cellulose nanomaterial;
- about 1 wt % to about 25 wt % of a water-soluble polymer comprising a plurality of first crosslinkable groups;
- and
- about 1 wt % to about 25 wt % of a water-soluble crosslinking agent comprising a plurality of second crosslinkable groups;
- wherein at least a portion of the second crosslinkable groups can form covalent bonds with at least a portion of the first crosslinkable groups and at least a portion of the hydroxy groups of the cellulose component;
- and
- wherein the composite foam has an apparent density of about 0.01 g/cm3 to about 0.25 g/cm3.
Dependencies are inferred from the claim text.