FIELD OF THE INVENTION

The presently disclosed subject matter relates generally to methods of making isocyanate-free foam. BACKGROUND

It is known to produce foam from a reactive mixture of one or more polyols and one or more isocyanates. Isocyanates are highly reactive and toxic chemicals and new warning label requirements are being implemented. It is desirable to move away from the use of isocyanates where there is a potential for consumer exposure. There are foams that use alternate chemistries to produce urethane linkages without using isocyanates. The presently disclosed matter offers an isocyanate-free foam that does not rely on urethanes to produce the foam and methods of making the isocyanate-free foam.

The benzoyl peroxide (BPO)/aromatic amine chemistry is well known for polymerizing unsaturated resins and is used commercially for curing unsaturated polyester composites. Typically, one part would have the peroxide and the second part would contain the aromatic amine promoter. When the 2 parts are mixed together, the amine induces the formation of free radicals by the reaction with the peroxide. These radicals then initiate the polymerization of unsaturated polyesters and/or reactive diluents. This exothermic reaction can be quite rapid even at room temperature (the heat of polymerization of acrylate reported in the literature is 19.2 kcal/mol, which is close to the heat of reaction of aromatic isocyanate with hydroxyl group on a polyol of 24 kcal/mol). SUMMARY

The presently disclosed subject matter is directed to a method of making a foam and the foam thereof. In some embodiments, the formulation for making the foam may have a first part, where the first part may have 15% to 45% of at least one bicarbonate dispersed in 40% to 70% of at least one acrylate, and 0.5% to 2% peroxide. The formulation may have a second part, where the second part may have 15% to 40% of at least one acid, and 1 % to 5% of an aromatic amine. The second part may also have water and/or at least one water reducible acrylate. The first part may be separated from the second part. The formulation may also have 0.05% to 3% surfactant, and the surfactant is included in at least one of the first part or the second part.

In other embodiments, the formulation for making the foam may have a first part, where the first part has 15% to 45% of at least one bicarbonate dispersed in 40% to 70% of at least one acrylate, and 1 % to 5% of an aromatic amine. The formulation may have a second part, where the second part has 15% to 40% of at least one acid, and 0.5% to 2% peroxide. The second part may also have water and/or at least one water reducible acrylate. The first part may be separated from the second part. The formulation may also have 0.05% to 3% surfactant, and the surfactant is included in at least one of the first part or the second part.

In some embodiments, the method of making a foam may include providing a formulation as described above. The method of making a foam may also include combining the first part and the second part of the formulation to create a froth comprising a generated gaseous blowing agent. The method of making a foam may further include curing the froth by free radical polymerization to produce a foam.

In some embodiments, the presently disclosed subject matter is directed to a foam. The foam may have 25% to 75% of at least one acrylate, 5% to 40% of at least one water-reducible acrylate, 10% to 40% of at least one acid, 10% to 40% of at least one salt of an acid, 1 % to 5% of an aromatic amine, 0.1 % to 3% of a surfactant, and carbon dioxide. The foam may also have less than or equal to 20% water. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative schematic diagram of an embodiment of the presently disclosed subject matter.

DETAILED DESCRIPTION

General Considerations

The presently disclosed subject matter is directed to a formulation and method for making a foam. The formulation may include a bicarbonate, at least one acrylate, a peroxide, an acid, at least one water-reducible acrylate and an aromatic amine.

Definitions

While the following terms are believed to be well understood by one of ordinary skill in the art, the following definitions are set forth to facilitate explanation of the presently disclosed subject matter.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently disclosed subject matter belongs.

Following long standing patent law convention, the terms "a", "an", and "the" refer to "one or more" when used in the subject application, including the claims. Thus, for example, reference to "a formulation" includes a plurality of such formulations, and so forth.

Unless indicated otherwise, all numbers expressing quantities of components, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the instant specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

As used herein, the term "about", when referring to a value or to an amount of mass, weight, time, volume, concentration, percentage, and the like can encompass variations of, and in some embodiments, ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1 %, in some embodiments ±0.5%, and in some embodiments ±0.1 %, ±0.01 %, from the specified amount, as such variations are appropriated in the disclosed package and methods. As used herein, the term "additive" refers to any substance, chemical, compound or formulation that is added to an initial substance, chemical, compound or formulation in a smaller amount than the initial substance, chemical, compound or formulation to provide additional properties or to change the properties of the initial substance, chemical, compound or formulation. As used herein, "polymerizable resin" refers to reactive molecules having three or more sites of ethylenic unsaturation that participate in forming covalent bonds during the free radical polymerization (i.e., have a functionality of three or more) to form larger molecules comprising multiples of the reactive molecules.

As used herein, "acrylate" includes acrylates, methacrylates, and molecules having combinations of acrylate and methacrylate functionalities. "Acrylate functionality" includes functionality provided by any of acrylate and methacrylate moieties. "Acrylate moieties" includes acrylate and methacrylate moieties. As used in this context, "acrylate functionality" refers to the number of acrylate moieties on the molecule.

As used herein, "co-reactant" is a molecule having two or fewer sites of ethylenic unsaturation that participate in forming covalent bonds during the free radical polymerization of the polymerizable resin (i.e., have a functionality of two or one). The co-reactant may be a reactive diluent, that is, co-reactant that can also act to lower the viscosity of a solution comprising the polymerizable resin (i.e., act as a solvent or diluent for the polymerizable resin). A co-reactant may be selected to improve one or more characteristics of the cured foam formulation, such as density, tensile strength, compressive strength, toughness, and/or modulus. As used herein, "froth" is the expanded mixture at the initial period of the curing process (i.e., polymerization process) comprising the polymerizable resin(s), co- reactants, and other components and a plurality of cells within the mixture created by carbon dioxide and other gases that have come out of solution or have vaporized in response to the decrease in pressure. The froth exists before curing has been completed. All formulation percentages used herein are presented on a "by weight" basis, unless designated otherwise.

Although the majority of the above definitions are substantially as understood by those of skill in the art, one or more of the above definitions can be defined herein above in a manner differing from the meaning as ordinarily understood by those of skill in the art, due to the particular description herein of the presently disclosed subject matter.

III. The Disclosed Formulation

The presently disclosed subject matter is directed to a formulation for making a foam and methods of making a foam. The formulation may include a bicarbonate, at least one acrylate, a peroxide, an acid, at least one water-reducible acrylate and an aromatic amine. The formulation may be in two parts: a first part and a second part. The first part may be referred to as the A-side. The second part may be referred to as the B-side. The formulation for making a foam may have two parts: the first part may have a bicarbonate, at least one acrylate and a peroxide; and the second part of the formulation for making a foam may have an acid and an aromatic amine. The second part may also have at least one water reducible acrylate. The formulation for making a foam may have two parts: the first part may have a bicarbonate, at least one acrylate and an aromatic amine; and the second part of the formulation for making a foam may have an acid and a peroxide. The second part may also have at least one water reducible acrylate. The first part and the second part may be isolated from one another until mixing the first part and the second part is desired and a gaseous blowing agent may be generated.

The formulation for making a foam may include at least one bicarbonate. The bicarbonate may be ammonium bicarbonate, calcium bicarbonate, potassium bicarbonate, sodium bicarbonate, or combinations thereof. The bicarbonate may be aqueous or solid. The at least one bicarbonate may be solid and may be a powder. In some embodiments, the at least one bicarbonate may be sodium bicarbonate. In other embodiments, the at least one bicarbonate may be solid sodium bicarbonate that is milled. The sodium bicarbonate may be finely milled. In other embodiments the at least one bicarbonate may be sodium bicarbonate and potassium bicarbonate. The formulation may have 15 wt% to 45 wt% of a bicarbonate. The formulation may have 15 wt%, 20 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, 36 wt%, 40 wt%, 42 wt%, 45 wt% of a bicarbonate or any range between any of these values. In some embodiments, the formulation may have 35 wt% sodium bicarbonate. In other embodiments, the formulation may have 28 wt% sodium bicarbonate. In further embodiments, the formulation may have 30.5 wt% sodium bicarbonate and 5.5 wt% potassium bicarbonate. In some embodiments, the bicarbonate may be in the first part. In other embodiments, the bicarbonate may be in the second part. The bicarbonate may be dispersed in at least one acrylate. The bicarbonate may be in the first part at a range of 15-45 wt% and may be dispersed in 40-70 wt% of at least one acrylate. The formulation for making a foam may include at least one acrylate. The acrylate may be 2-hydroxyethyl methacrylate, acrylated polyester oligomers, bisphenol A diacrylates, dipropylene glycol diacrylate, epoxy acrylates, ethoxylated bisphenol A diacrylate, isobornyl acrylate, PEG 600 diacrylate, polyethylene glycol diacrylates, propylene glycol diacrylates, polypropylene glycol diacrylate, bisphenol A dimethacrylate, acrylated polyester oligomer, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, zinc diacrylate or combinations thereof. The acrylate may be a solid, a liquid or a paste. In some embodiments, the at least one acrylate may be trimethylolpropane triacrylate (TMPTA), dipropylene glycol diacrylate and 2-hydroxyethyl methacrylate. In other embodiments, the at least one acrylate may be TMPTA, dipropylene glycol diacrylate, PEG 600 diacrylate and 2-hydroxyethyl methacrylate. The at least one acrylate may be TMPTA and dipropylene glycol diacrylate. The at least one acrylate may be TMPTA. The at least one acrylate may be dipropylene glycol diacrylate. The at least one acrylate may be PEG 600 diacrylate. The at least one acrylate may be 2-hydroxyethyl methacrylate. The at least one acrylate may be TMPTA, dipropylene glycol diacrylate, ethoxylated (10 moles) bisphenol A diacrylate and 2-hydroxyethyl methacrylate.

The formulation may have 50 wt% to 90 wt% of at least one acrylate. The formulation may have 40 wt% to 70 wt% of at least one acrylate. The formulation may have 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt% of at least one acrylate or any range between these values. In some embodiments, the at least one acrylate is in the first part. In other embodiments, the at least one acrylate is in the second part. In further embodiments, the at least one acrylate is in the first part and the second part. The formulation may have 50 wt% to 80 wt% of at least one acrylate in the first part. The formulation may have 40 wt% to 70 wt% of at least one acrylate in the first part. The first part may have 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt% of at least one acrylate or any range between these values. The formulation may have 5 wt% to 30 wt% of at least one acrylate in the second part. The second part may have 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt% of at least one acrylate or any range between these values.

The formulation for making a foam may include a peroxide. The formulation for making a foam may include a plurality of peroxides. The peroxide may be barium peroxide, dibenzoyi peroxide, methyl ethyl ketone peroxide, hydrogen peroxide sodium peroxide, t-butyl peroxybenzoate or combinations thereof. The peroxide may be a solid, a liquid or a paste. The peroxide may be a finely milled solid. The peroxide may be a dibenzoyi peroxide. In some embodiments, the peroxide may be a dibenzoyi peroxide dispersion or solution. The dibenzoyi peroxide dispersion may be 40% dibenzoyi peroxide in a plasticizer.

The formulation may have 1 wt% to 5 wt% of a peroxide. The formulation may have 1 .0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt% of a peroxide or any range between these values. The peroxide may be 2.5 wt% of 40% dibenzoyi peroxide in a plasticizer. The peroxide may be in the first part. The peroxide may be in the second part.

The formulation for making a foam may include at least one acid. The acid may be acetic acid, citric acid, malic acid, tartaric acid, lactic acid, methacrylic acid, 2- hydroxyethylmethacrylate acid phosphate, poly(acrylic acid), phosphoric acid, phosphate esters of 2-hydroxyethyl methacrylate or combinations thereof. The acid may be a solid, a liquid, a solution, or a paste. The acid may be on a dry basis. In some embodiments the acid may be aqueous citric acid. The at least one acid may be citric acid and methacrylic acid. The citric acid may be a 59% citric acid solution.

The formulation may have 15 wt% to 50 wt% of at least one acid. The formulation may have 15 wt% to 40 wt% of at least one acid. The formulation may have 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt% of at least one acid or any range between these values. The formulation may have 30 wt% of at least one acid. The formulation may have 38% of at least one acid. The formulation may have 43% of at least one acid. In some embodiments, the formulation may have at least one acid in the second part. The formulation may have 26 wt% aqueous citric acid. In other embodiments, the formulation may have 33 wt% aqueous citric acid. In further embodiments, the formulation may have 38 wt% aqueous citric acid. The formulation may have 4% methacrylic acid. In some embodiments, the formulation may have 5 wt% methacrylic acid. In further embodiments, the formulation may have 10 wt% methacrylic acid.

The formulation for making a foam may include at least one water-reducible acrylate. The at least one water-reducible acrylate may be metallic diacrylates, metallic methacrylates, ethoxylated or propoxylated triacrylates, ethoxylated diacrylates, propoxylated diacrylates, or any combination thereof. The at least one water reducible acrylate may be zinc diacrylate, ethoxylated (3 moles) trimethylol propane triacrylate, ethoxylated (9 moles) trimethylol propane triacrylate, ethoxylated (10 moles) trimethylol propane triacrylate, ethoxylated (15 moles) trimethylol propane triacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate or any combination thereof. The at least one water-reducible acrylate may be 2-hydroxyethyl methacrylate phosphate, ethoxylated bisphenol A diacrylate, PEG 600 diacrylate, PEG 400 diacrylate, polyethylene glycol diacrylates, triacrylates, diacrylates, zinc diacrylate or combinations thereof. In some embodiments, the at least one water-reducible acrylate may be zinc diacrylate. In other embodiments, the at least one water-reducible acrylate may be zinc diacrylate and other reducible acrylates. The at least one water-reducible acrylate may be ethoxylated (20 moles) trimethylolpropane triacrylate and zinc diacrylate. The at least one water-reducible acrylate may be ethoxylated (9 moles) trimethylolpropane triacrylate and zinc diacrylate. The at least one water-reducible acrylate may be ethoxylated (20 moles) trimethylolpropane triacrylate, ethoxylated (9 moles) trimethylolpropane triacrylate and zinc diacrylate. In some embodiments, the at least one water-reducible acrylate may be 30% aqueous zinc diacrylate.

The formulation may have 15 wt% to 45 wt% of at least one water-reducible acrylate. The formulation may have 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% of at least one water reducible acrylate or any range between these values. The formulation may have at least one water reducible acrylate in the second part.

The formulation for making a foam may include an aromatic amine. In some embodiments, the aromatic amine may be Ν,Ν-dimethyl aniline, N-methyl aniline, N,N- dimethyltoluidine, N-methyltoluidine, N-(2-hydroxyethyl)-N-methyl-p-toluidine, N-alkyl aniline, N-alkyl toluidine, or any combination thereof. The aromatic amine may be N-(2- hydroxyethyl)-N-methyl-p-toluidine (MHPT). The formulation may have an aromatic amine in the first part. The formulation may have an aromatic amine in the second part. In general, the aromatic amine will be in the part that does not contain peroxide.

The formulation may have 1 wt% to 5 wt% of an aromatic amine. The formulation may have 1 wt%, 1 .25 wt%, 1.5 wt%, 1 .75 wt%, 1 .9 wt%, 2.0 wt%, 2.25 wt%, 2.5 wt%, 2.75 wt%, 3 wt%, 3.25 wt%, 3.5 wt%, 3.75 wt%, 4 wt%. 4.25 wt%, 4.5 wt%, 4.85 wt%, 5 wt% of an aromatic amine or any range between these values. In some embodiments, the formulation may have 1 .9 wt% of MHPT in the second part of the formulation.

The formulation for making a foam may have at least one additive. In some embodiments, the formulation may include 0.005 wt%, 0.007 wt%, 0.008 wt%, 0.01 wt%, 0.05 wt%, 0.075 wt%, 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1 .2 wt%, 1 .4 wt%, 1 .44 wt%, 1 .75%, 1 .8 wt%, 1 .82%, 1.83 wt%, 2.0 wt%, 3.0 wt%, 4.0%, 4.5 wt%, 4.6 wt%, 4.62 wt%, 5.0 wt%, 5.25 wt%, 5.3 wt%, 5.32 wt%, 5.5 wt%, 6 wt%, 7 wt%, 10 wt% of at least one additive or any range between any of these values. The at least one additive may be in the first part. The formulation may have at least one additive in the second part. The formulation may have at least one additive in the first part and the second part.

The at least one additive may be a dye, flame retardant, pigment dispersing agent, reinforcing agent, nucleating agent, surfactant, unsaturated polyester type resin or combinations thereof. In some embodiments, the at least one additive may be a dye and a pigment dispersing agent. In other embodiments, the at least one additive may be a dye, a pigment dispersing agent and a silicon surfactant. In further embodiments, the at least one additive may be a dye, a pigment dispersing agent, and a silicon surfactant. In yet further embodiments, the at least one additive may be aluminum hydroxide, cellulose fibers, a dye, a pigment dispersing agent, silicas, a silicon surfactant, and chitin nanowhiskers. The formulation may have at least one additive in the first part, the second part or both the first and the second part. The at least one additive may be a pigment dispersing agent and a silicone surfactant in the first part. The at least one additive may be a dye and a silicone surfactant in the second part. The at least one additive may be a dye, silicone surfactant, and 2-hydroxyethyl methacrylate phosphate in the second part. In some embodiments, the at least one additive may be a pigment dispersing agent and a silicone surfactant in the first part and a dye and a silicone surfactant in the second part. In other embodiments, the at least one additive may be a pigment dispersing agent and a silicone surfactant in the first part and a dye and a silicone surfactant in the second part.

In some embodiments, the formulation may have 0.05 wt% to 3 wt% of a surfactant. The formulation may have 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.75 wt%, 1 .0 wt%, 1 .25 wt%, 1.5 wt%, 1 .75 wt%, 2.0 wt%, 2.25 wt%, 2.5 wt%, 2.75 wt%, 3.0 wt% of a surfactant or any range between any of these values.

Methods of Making the Disclosed Formulation

The method of making a foam may include providing the formulation mentioned previously. FIG. 1 represents an embodiment of a method of making the foam. As seen in FIG. 1 , the first part may be in vessel A 5, and the second part may be in vessel B 20. The first part may be transported to a mixing chamber 15 by stream 10 that connects vessel A 5 to the mixing chamber 15. The second part may be transported to a mixing chamber 15 by stream 25 that connects vessel B 20 to the mixing chamber 15.

Additionally, the method of making a foam may include combining the first part and the second part of the formulation to create a froth with a generated gaseous blowing agent by any suitable means. The first part and the second part may be mixed together in the mixing chamber 15. A stream of the first part, for example, in stream 10 may be impinged or entrained with a stream of the second part, for example, in stream 25. Also by example, a stream of the second part, for example, in stream 25 may be impinged or entrained with a stream of the first part, for example, in stream 10. The first part and the second part may be hand mixed or mixed by a machine. The mixing device may be a static mixing device. The mixing device may be a disposable mixing device. In some embodiments, the step of combining is performed with a static mixer.

The step of combining may be done at various temperatures. In some

embodiments, the step of combining may be done at ambient temperature. In other embodiments, the step of combining may be done at a temperature of 5°C to 60°C. The temperature may be 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, or any range between these values.

Simultaneously or soon after the mixing, the resulting mixture in stream 30 may be expanded to create a froth. The froth may be transported to a dispensing chamber 35 by stream 30 that connects the mixing chamber 15 to the dispensing chamber 35. The dispensing chamber 35 may dispense the froth using stream 40. The method of making a foam may further include curing the froth by free radical polymerization to produce a foam.

The first part and the second part may be combined at a mixing pressure of, for example, at least any one of 10 psig, 100 psig, 200 psig, 300 psig, 350 psig, 500 psig, and 800 psig, for example in mixing chamber 15 to form a resulting mixture. The resulting mixture may have an initial temperature, for example, of at least 5°C, 10°C, 20°C, 30°C, 40°C, 50°C, and 60°C or any range between these values. The curing reaction begins upon mixing, for example, within the mixing chamber 15.

The step of expanding the resulting mixture in stream 30 to create the froth may occur by discharging the mixture directly from the mixing chamber 15 to ambient conditions (not illustrated), or alternatively by discharging the mixture into a dispensing chamber 35. In the latter case, the froth may then be discharged from the dispensing chamber 35 to allow the curing process to proceed to completion and create the foam outside of the dispensing chamber.

A blowing agent may be generated during the step of mixing. In some embodiments, a blowing agent may be added during the step of mixing. The blowing agent may be a generated gaseous blowing agent. In some embodiments the generated gaseous blowing agent is carbon dioxide.

The polymerizable resin along with any of the additional ingredients within the froth are cured to create a solidified matrix surrounding or encasing the cellular structure of the plurality of cells to create the foam. The temperature of the mixture or froth may be elevated in a controlled fashion to help control the rate of the curing reaction, as well as potentially extending the curing reaction. Typically the curing is exothermic, so that the temperature of the system will typically rise after initiation of the curing reaction. The curing may be 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 1 minute, 2 minutes, 3 minutes, 4 minutes or any range between these values. In some embodiments, the foam may be tack free in 2 minutes or less. In other embodiments, the foam may be tack free in 2 minutes, 1 10 seconds, 100 seconds, 90 seconds, 80 seconds, 70 seconds, 60 seconds, 50 seconds, 40 seconds, 30 seconds, 20 seconds, 10 seconds or any range between these values. The term "tack free" is the period from the start of the cure to a point when the foam is sufficiently robust to resist damage by touch or in ad hoc testing. Tack free time can be determined as the point when the surface of the foam is no longer sticky when touched.

The method of making a foam may include providing a formulation. The formulation may have a first part comprising 15% to 45% of at least one bicarbonate dispersed in 40% to 70% of at least one acrylate, and 1 % to 5% peroxide. In some embodiments, the formulation may have a first part comprising 15% to 45% of at least one bicarbonate dispersed in 40% to 70% of at least one acrylate, and 1 % to 5% of an aromatic amine. The formulation may have a second part comprising 15% to 40% of at least one acid, 1 % to 5% of an aromatic amine. In other embodiments, the formulation may have a second part comprising 15% to 40% of at least one acid, and 1 % to 5% peroxide. The second part may include water. The second part may have at least one water reducible acrylate. The first part may be separated from the second part. The formulation may have 0.05% to 3% surfactant, and the surfactant may be included in at least one of the first part or the second part. The method may include combining the first part and the second part of the formulation to create a froth with a generated gaseous blowing agent. The method may include curing the froth by free radical polymerization to produce a foam.

The bicarbonate reacts with the at least one acid in the formulation to generate a gaseous blowing agent and water. The gaseous blowing agent may be carbon dioxide. In some embodiments, the bicarbonate is sodium bicarbonate. In other embodiments, the bicarbonate is sodium bicarbonate and potassium bicarbonate. In general, there is typically a slight excess of bicarbonate to ensure that the aromatic amine is no longer protonated by the acid, then the aromatic amine is free to promote the peroxide decomposition. By using milled bicarbonate the foam may have a lower density. The average particle size of standard sodium bicarbonate is about 40 microns and produces a foam with good properties. A lower density foam may be produced by using milled bicarbonate with an average particle size of about 9 microns. Thus, the particle size of the bicarbonate can be used to control the initial dissolution/reaction rate with the acid. In some embodiments, the formulation for making a foam has a peroxide that is dibenzoyl peroxide. Dibenzoyl peroxide splits homolytically into two free radicals that initiate polymerization of the at least one acrylate. The primary decomposition product of dibenzoyl peroxide is benzoic acid. In some embodiments, the foam produced may have benzoic acid in addition to the at least one acid that was in the formulation. The foam may have benzoic acid, citric acid, methacrylic acid, and/or their salts.

Foam The foam may have at least one acrylate, at least one water-reducible acrylate, at least one acid, at least one salt of an acid, an aromatic amine, carbon dioxide, and a surfactant. The foam may also have water. In some embodiments, the foam may have 25% to 75% of at least one acrylate, 5% to 40% of at least one water-reducible acrylate, 10% to 40% of at least one acid, 10% to 40% of at least one salt of an acid, 1 % to 5% of an aromatic amine, 0.1 % to 3% of a surfactant, and carbon dioxide. The foam may have less than or equal to 20% water.

The foam (i.e., cellular plastic) may have a density of 0.25 pounds per cubic foot (pcf), 0.5 pcf, 1 .0 pcf, 1 .1 pcf, 1 .2 pcf, 1 .3 pcf, 1 .4 pcf, 1 .5 pcf, 1 .6 pcf, 1 .7 pcf, 1 .8 pcf, 1 .9 pcf, 2.0 pcf, 2.1 pcf, 2.5 pcf, 3.0 pcf, 4.0 pcf, and 5.0 pcf, or any range between these values. In some embodiments, the foam may have a density of less than or equal to 3.0 pcf. For protective packaging (e.g., cushioning) applications, lower densities are typically preferred. Unless otherwise noted, the density of the foam as used herein is the apparent density measured according to ASTM D1622-08, which is incorporated herein in its entirety by reference.

The foam may have a compressive strength at 10% strain of at least any of the following: 0.1 psi, 0.5 psi, 0.8 psi, 1 .0 psi, 1 .1 psi, 1.2 psi, 1.3 psi, 1 .4 psi, 1.5 psi, 2.0 psi, 2.5 psi, 3.0 psi, and 3.5 psi, or any range between these values, for example at from 10 to 50% compression. In some embodiments the foam may have a compressive strength of greater than or equal to 1 psi at 10% strain. As used herein, the compressive strength is measured according to ASTM 1621 -00, as modified by reference to 10% strain.

The foam may have a compressive strength at 25% strain of at least any of the following: 0.8 psi, 0.9 psi, 1 .0 psi, 1 .2 psi, 1 .3 psi, 1.4 psi, 1.5 psi, 1 .6 psi, 1.7 psi, 1 .8 psi, 1.9 psi, 2.0 psi, and 2.5 psi, or any range between these values, for example at from 10 to 50% compression. As used herein, the compressive strength is measured according to ASTM 1621 -00, as modified by reference to 25% strain. The foam may have a compressive strength at 50% strain of at least any of the following: 0.8 psi, 1 .0 psi, 1 .1 psi, 1 .2 psi, 1 .3 psi, 1.4 psi, 1.5 psi, 1 .6 psi, 1.7 psi, 1 .8 psi, 1 .9 psi, 2.0 psi, 2.1 psi, 2.2 psi, 2.3 psi, 2.4 psi, and 2.5 psi, or any range between these values, for example at from 10 to 50% compression. As used herein, the compressive strength is measured according to ASTM 1621 -00, as modified by reference to 50% strain.

The foam may have a configuration, for example, of any of a sheet, plank, slab, block, board, and molded shape. The foam may be a solid foam. The foam may be used for any one or more of void fill, blocking or bracing, thermal insulation, cushioning, package cushioning, sound insulation or vibration dampening.

In preferred embodiments, the formulations used to make the foam are free of isocyanate reactants, such as those used in formulating polyurethane foams, so that the final foam of the present disclosure is free from isocyanates or isocyanate residues.

Any numerical value ranges recited herein include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable (e.g., temperature, pressure, time) may range from any of 1 to 90, 20 to 80, or 30 to 70, or be any of at least 1 , 20, or 30 and/or at most 90, 80, or 70, then it is intended that values such as 15 to 85, 22 to 68, 43 to 51 , and 30 to 32, as well as at least 15, at least 22, and at most 32, are expressly enumerated in this specification. For values that are less than one, one unit is considered to be 0.0001 , 0.001 , 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

The above descriptions are those of preferred embodiments of the invention.

Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the claims, which are to be interpreted in accordance with the principles of patent law, including the doctrine of equivalents. The definitions and disclosures set forth in the present Application control over any inconsistent definitions and disclosures that may exist in an incorporated reference. All references to ASTM tests are to the most recent, currently approved, and published version of the ASTM test identified, as of the priority filing date of this application. Each such published ASTM test method is incorporated herein in its entirety by this reference.

EXAMPLES

The following Examples provide illustrative embodiments. In light of the present disclosure and the general level of skill in the art, those of ordinary skill in the art will appreciate that the following Examples are intended to be exemplary only and that numerous changes, modifications, and alterations can be employed without departing from the scope of the presently disclosed subject matter. EXAMPLE 1

FORMULATION DEVELOPMENT

Several 2-part (1 : 1 mix ratio) ambient cure formulations were prepared. The ingredients were mixed using either a manual or a pneumatic 1 :1 MIXPAC™ cartridge system using various static mixing heads. Different formulations were tested to try to lower density and increase compressive strength. Two formulation options were developed. The main difference between the two was in which part the peroxide and amine was located. It was found that decreasing the particle size of the bicarbonate by jet milling gave a dramatic increase in foam volume. The foam volume obtained using the non-milled bicarbonate was doubled by switching to the jet milled bicarbonate.

Tables 1 , 3, 5, 7, and 9 lists the A-side formulation for examples 1 -25 and Tables 2, 4, 6, 8, and 10 lists the B-side formulation for examples 1 -25. Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

EXAMPLE 2

Mechanical Property Testing

Examples 1 -25 were tested for density, compressive strength (at 10%, 25% and 50%). The slope and ratio (10%/d) were also calculated. The "slope" is the slope of the compressive strength data, thus a greater slope means a greater increase in

compressive strength with increasing strain. The "ratio" is the compressive strength at 10% divided by the density, thus a larger ratio is a stronger foam for a given density. With all things being equal it is expected that compressive strength would rise and fall with density. Tables 1 1 -15 lists the properties for Examples 1 -25. Table 1 1

Table 12

The comparison of examples 1 -1 1 show that example 1 had the lowest density of 1 .57 pcf and example 10 had the highest density of 2.09 pcf. The compressive strength was determined at 10%, 25% and 50% compressive strain. Example 1 showed the least resistance to compressive stresses due perhaps to having the lowest density out of examples 1 -1 1 . Example 1 had a compressive strength of 1 psi at 10% strain and 1 .28 psi at 50% strain. In Tables 1 1 and 12, examples 3 and 9 had the highest compressive strength at 10% strain. Example 10 had the highest resistance to compressive stresses when compared to examples 1 -9 and 1 1 due perhaps to having the highest density. Example 10 had a compressive strength of 1 .33 psi at 10% and 1 .8 psi at 50%. Examples 3, 5, 8, and 9 had the highest strength to density ratio when compared to all of the examples in Tables 1 1 and 12. Table 13

Examples 13 and 14 had the lowest density, although example 17 had the greatest compressive strength to density ratio compared to all of the examples in Table 13.

Table 14

Examples 19 and 22 had the lowest density and example 19 had a high pressive strength to weight ratio compared to all of the examples in Table 14.

Table 15

Examples 23 and 24 had lower density values than example 25. Example 24 had the best compressive strength to density ratio when compared to examples 23 and 24.