US-12617917-B2 - Biodegradable foam with alginate

Abstract

A foam is described. The foam comprising a polymer matrix including at least one of chitin, chitosan, or chitosan oligosaccharide. The polymer matrix is porous. The foam further comprising alginate. The foam has a density of less than 1 g/cm 3 . A method of making foam is described. The method comprising dissolving at least one of chitin, chitosan, or chitosan oligosaccharide in a first solution, dissolving alginate in a second solution that is alkaline and separate from the first solution, mixing the first solution and the second solution together to form a foam precursor, and drying the foam precursor to form the foam.

Inventors

• William Thomas Lewczyk
• Grant Scott Logan

Assignees

• CRUZ FOAM, INC.

Dates

Publication Date

20260505

Application Date

20221004

Claims (19)

1. 1 . A foam, comprising: a polymer matrix including at least one of chitin, chitosan, or chitosan oligosaccharide, wherein the polymer matrix is porous; and alginate disposed in the foam, wherein the foam has a density of less than 1 g/cm 3 , wherein: (i) a chitosan weight percent representative of the chitosan included in the foam is greater than an alginate weight percent representative of the alginate included in the foam; or (ii) a chitin weight percent representative of the chitin included in the foam is greater than the alginate weight percent.
2. 2 . The foam of claim 1 , wherein the alginate includes at least one of alginic acid, sodium alginate, or calcium alginate.
3. 3 . The foam of claim 1 , further comprising a salt disposed in the foam, and wherein the salt includes a sodium salt or a calcium salt.
4. 4 . The foam of claim 1 , further comprising a dispersed phase disposed within the polymer matrix, wherein the dispersed phase includes at least one of chitin, starch, cellulose, shellfish shells, wood flour, hemp, paper pulp, coconut husks, cornstarch, pea starch, or tapioca powder.
5. 5 . The foam of claim 1 , wherein a ratio of the alginate to the chitosan included in the foam ranges from 1 part alginate to 20 parts chitosan to one part alginate to 5 parts chitosan.
6. 6 . The foam of claim 1 , wherein the chitosan weight percent is less than a dispersed phase weight percent representative of a dispersed phase included in the foam.
7. 7 . A method of making foam, comprising: dissolving at least one of chitin, chitosan, or chitosan oligosaccharide in a first solution; dissolving alginate in a second solution, separate from the first solution, wherein the second solution is alkaline; and mixing the first solution and the second solution together to form a foam precursor; and drying the foam precursor to form the foam, wherein the foam comprises a polymer matrix including at least one of the chitin, the chitosan, or the chitosan oligosaccharide, wherein the polymer matrix is porous, wherein the foam further comprises alginate, wherein the foam has a density of less than 1 g/cm 3 , and wherein: (i) a chitosan weight percent representative of the chitosan included in the foam is greater than an alginate weight percent representative of the alginate included in the foam; or (ii) a chitin weight percent representative of the chitin included in the foam is greater than the alginate weight percent.
8. 8 . The method of claim 7 , wherein the first solution is acidic that includes at least one of acetic acid, formic acid, lactic acid, hydrochloric acid, nitric acid, or sulfuric acid, wherein the second solution includes sodium bicarbonate or calcium carbonate, and wherein the mixing the first solution and the second solution together produces a gas, and wherein the gas produces pores in the foam.
9. 9 . The method of claim 7 , further comprising mixing a dispersed phase material into at least one of the first solution or the second solution, wherein the dispersed phase material includes at least one of chitin, starch, cellulose, shellfish shells, wood flour, hemp, paper pulp, coconut husks, cornstarch, pea starch, or tapioca powder.
10. 10 . The method of claim 7 , wherein there is more of the chitosan included in the first solution, by weight, relative to the alginate included in the second solution, wherein a ratio of the alginate to the chitosan included in the foam ranges from 1 part alginate to 20 parts chitosan to one part alginate to 5 parts chitosan.
11. 11 . A method of producing foam, comprising: inputting a first solution into an extruder, wherein the first solution includes at least one of chitin, chitosan, or chitosan oligosaccharide; inputting a second solution into the extruder, wherein the second solution includes alginate; inputting a plasticizer into the extruder, and outputting a foam from the extruder as an extrudate, wherein the foam includes the alginate, the plasticizer, and least one of the chitin, the chitosan, or the chitosan oligosaccharide, wherein the foam comprises a polymer matrix including at least one of the chitin, the chitosan, or the chitosan oligosaccharide, wherein the polymer matrix is porous, wherein the foam further comprises the alginate and the plasticizer, wherein a weight percent of the plasticizer for the foam is greater than a weight percent of the alginate for the foam, and wherein the foam has a density of less than 1 g/cm 3 .
12. 12 . The method of claim 11 , wherein there is more of the chitosan included in the first solution, by weight, relative to the alginate included in the second solution such that a chitosan weight percent representative of the chitosan included in the foam is greater than an alginate weight percent representative of the alginate included in the foam.
13. 13 . The method of claim 12 , wherein a ratio of the alginate to the chitosan included in the foam ranges from 1 part alginate to 20 parts chitosan to one part alginate to 5 parts chitosan.
14. 14 . The method of claim 11 , adjusting a quantity of the alginate included in the second solution to control a strength of the foam.
15. 15 . A foam, comprising: a polymer matrix including at least one of chitin, chitosan, or chitosan oligosaccharide, wherein the polymer matrix is porous; alginate disposed in the foam, wherein the foam has a density of less than 1 g/cm 3 ; and a dispersed phase disposed within the polymer matrix, wherein a weight percent of the polymer matrix is less than a weight percent of the dispersed phase.
16. 16 . The foam of claim 15 , wherein a weight percent of the polymer matrix is between 0.5-3 times that of a weight percent of the dispersed phase.
17. 17 . A foam, comprising: a polymer matrix including at least one of chitin, chitosan, or chitosan oligosaccharide, wherein the polymer matrix is porous; alginate disposed in the foam, wherein the foam has a density of less than 1 g/cm 3 ; and a plasticizer, and wherein a weight percent of the plasticizer is greater than a weight percent of the alginate.
18. 18 . The foam of claim 17 , wherein the plasticizer includes at least one of a polyol or a carbamide.
19. 19 . The foam of claim 17 , further comprising a dispersed phase disposed within the polymer matrix, wherein the weight percent of the plasticizer is greater than a weight percent of the chitosan, and wherein the weight percent of the plasticizer is less than a weight percent of the dispersed phase.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application No. 63/251,834, filed on Oct. 4, 2021, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This disclosure relates generally to foam manufacturing and products, and in particular but not exclusively, relates to biodegradable foam manufacturing. BACKGROUND INFORMATION Plastic pollution is hazardous to life on earth. Plastic may take hundreds of years to degrade, may be ingested by animals and humans, and may cause health problems such as cancer. Plastic foams (e.g., expanded polystyrene) are ubiquitously used as packaging materials and significantly contribute to environmental plastic pollution. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. Not all instances of an element are necessarily labeled so as not to clutter the drawings where appropriate. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles being described. FIG. 1 illustrates an example biodegradable foam with alginate produced using the ingredients and methods described herein, in accordance with embodiments of the present disclosure. FIG. 2 illustrates chemical compositions of various ingredients that may be utilized to form a biodegradable foam, in accordance with embodiments of the present disclosure. FIG. 3 illustrates example stress-strain curve data for biodegradable foams formed with varying amounts of alginate, in accordance with embodiments of the present disclosure. FIGS. 4A-4B illustrate example schematics for fabricating biodegradable foam using an extruder, in accordance with embodiments of the present disclosure. FIGS. 5A-5B illustrate example methods for foaming biodegradable foam with alginate, in accordance with embodiments of the present disclosure. FIG. 6 illustrates example products with a three-dimensional shape formed of a biodegradable foam with alginate, in accordance with embodiments of the present disclosure. DETAILED DESCRIPTION Set forth herein are non-toxic biodegradable foam with alginate and methods of producing the biodegradable foam that solve the problems associated with conventional plastics and plastic foams. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Throughout this specification, several terms of art are used. These terms are to take on their ordinary meaning in the art from which they come, unless specifically defined herein or the context of their use would clearly suggest otherwise. It should be noted that element names and symbols may be used interchangeably through this document (e.g., Si vs. silicon); however, both have identical meaning. Inorganic plastics and plastic foams are ubiquitous. Expanded polystyrene is regularly used as a packaging material. However, inorganic plastics and plastic foams have become a major environmental pollutant, do not biodegrade, use toxic non-renewable precursors, and may cause health problems such as cancer. Described herein are precursors and methods of manufacturing which may be used to make biodegradable nontoxic polymers and polymer foams. Petroleum-based foams suffer from many drawbacks. The foams described herein are biodegradable, nontoxic, and produced with nontoxic precursors and through environmentally friendly processes. As will be shown, these biodegradable foams represent a significant advancement over existing industrial foam technologies since the biodegradable foams have similar or better mechanical, chemical, and thermal properties than the petroleum-based foams, with none of the negative environmental impact. The nontoxic polymers and polymer foams described herein may use renewable precursors and do biodegrade. Thus, the polymers (e.g., foam, and/or products made from the foam) and