Lignocellulosic composites prepared with aqueous alkaline and urea solutions in cold temperatures systems

Patent metadata

Field	Value
Publication number	US-12060679-B2
Application number	US-202117212345-A
Country	US
Kind code	B2
Filing date	Mar 25, 2021
Priority date	Feb 9, 2016
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

Unique, inexpensive, and. strong biocomposites are obtained from blending cellulose matrix materials pith lignocellulosic reinforcement materials with the aid of alkaline aqueous solvent and cold temperatures. These lignocellulosic composites (LCs) are produced without use of any thermoplastic resins, adhesives, catalysts, plasticizers or d chemical or physical procedures. The LCs include a matrix and a reinforcement material. The matrix is a cellulose material (e.g., cotton, hemp, flax, or wood) that is liquefied using an aqueous alkaline solvent solution under cold temperatures to more readily adhere and or incorporate/encapsulate the lignocellulosic reinforcements (wood chips, fibers, and other lignocellulosic sources).

First claim

The invention claimed is:

1. A composition comprising refined cellulosic material and untreated lignocellulosic reinforcement material, wherein said composition does not comprise an adhesive and does not comprise a resin, and wherein the composition is completely biodegradable and compostable.

2. The composition of claim 1 , wherein the composition comprises 15%-35% by weight of the refined cellulosic material and 65%-85% by weight of untreated lignocellulosic reinforcement material.

3. The composition of claim 2 , wherein the composition comprises about 25% by weight of the refined cellulosic material and about 75% by weight of untreated lignocellulosic reinforcement material.

4. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material consists of high aspect ratio fibers.

5. The composition of claim 4 , wherein said high aspect ratio fibers have a length of equal to or greater than 5 millimeters in one dimension and less than 5 millimeters in every other dimension.

6. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material consists of low aspect ratio chips.

7. The composition of claim 6 , wherein said low aspect ratio chips have a length of equal to or greater than 5 millimeters in two or three dimensions.

8. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material comprises one or more of wood flour, wood fibers, lumber strips, wood chips, wood sawdust, agricultural stem and branch waste materials, flax fibers, hemp fibers, Kenaf fibers, corn fibers, recycled cotton, waste cotton, press cakes derived from oil seeds, dried distiller's grain, miscellaneous cotton ginning mill waste, Kenaf fibers, waste cellulosic fibers, shredded books, paper bags, paper towels, stationary paper, woven processed mats, non-woven processed mats, and linings or bagging obtained from tree, herbs and crops.

9. The composition of claim 1 , wherein the refined cellulosic material comprises cellulose from partially solubilized cellulose-containing material.

10. The composition of claim 1 , wherein the refined cellulosic material comprises any one or more of cardboard, nanocellulose, crystalline cellulose, flax, cotton, recycled cotton, waste cotton, waste and stationary cellulosic fibers, shredded books, paper bags, paper towels, and stationary paper.

11. The composition of claim 1 , wherein the refined cellulosic material is cotton with a cellulose content of about 94% by weight.

12. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material consists of any one or both of Osage orange wood and agave fibers.

13. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material comprises 33% cellulose by weight, 17% hemicellulose by weight, and 40% lignin by weight.

14. The composition of claim 1 , wherein the untreated lignocellulosic reinforcement material comprises 43% cellulose by weight, 19% hemicellulose by weight, and 15% lignin by weight.

15. A biodegradable lignocellulosic composition comprising about 25% by weight of activated cellulose and about 75% by weight of untreated lignocellulosic reinforcement material having a length of equal to or greater than 5 millimeters in one dimension.

16. The biodegradable lignocellulosic composition of claim 15 , wherein the activated cellulose is produced by partially solubilizing a cellulose-containing material in an alkaline solution.

17. The biodegradable lignocellulosic composition of claim 16 , wherein the cellulose-containing material comprises any one or more of cardboard, nanocellulose, crystalline cellulose, flax, cotton, recycled cotton, waste cotton, waste and stationary cellulosic fibers, shredded books, paper bags, paper towels, and stationary paper.

18. The biodegradable lignocellulosic composition of claim 15 consisting of about 15%-35% by weight of said activated cellulose and about 65%-85% by weight of said untreated lignocellulosic reinforcement material.

19. A composite lignocellulosic composition produced by:
providing an alkaline solution comprising a predetermined volume of solvent, a predetermined volume of urea and a predetermined volume of water, said alkaline solution having a measurable temperature;
adding or removing heat to adjust the measurable temperature of the alkaline solution to a predetermined temperature, wherein the predetermined temperature is negative 10 degrees Celsius or lower;
combining a predetermined quantity of cellulose with the alkaline solution at said predetermined temperature to form a cellulose matrix;
combining a predetermined quantity of reinforcement material, which comprises cellulose, lignin, and hemicellulose and has a length of equal to or greater than 5 millimeters in one dimension, with the cellulose matrix gel to form a reinforcement-containing cellulose gel;
removing substantially all of the solvent and urea from the reinforcement-containing cellulose gel by solvent exchange in water to form a dough;
molding the dough into a predetermined shape; and then
drying the dough.

20. The composite lignocellulosic composition of claim 19 comprising about 15%-35% by weight of the cellulose and 65%-85% by weight of the reinforcement material, wherein said composite lignocellulosic composition does not comprise an adhesive or a resin.

Assignees

• Bradley Univ
• Us Agriculture

Inventors

• Tisserat Brent
• Haverhals Luke
• Liu Zengshe

Classifications

• C08L2201/06

  Biodegradable · CPC title

• C08L97/02

  Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} · CPC title

• D21C3/22

  Other features of pulping processes · CPC title

• D21J3/00

  Manufacture of articles by pressing wet fibre pulp, or papier-mâché, between moulds · CPC title

• D21C5/00

  Other processes for obtaining cellulose, e.g. cooking cotton linters (obtaining fibres for spinning D01C); {Processes characterised by the choice of cellulose-containing starting materials} · CPC title