Method for recycling polyurethane materials

Abstract

A method for recycling a polyurethane material, wherein the polyurethane material comprises a structural portion capable of being decomposed by acid hydrolysis, the method comprising: contacting the polyurethane material with an acid solution to decompose at least a portion of the polyurethane material into a recycled feedstock composition comprising degradation compounds; and introducing an acetoacetylated polyol into the recycled feedstock composition and reacting the acetoacetylated polyol with the degradation compounds to form a polyol compound.

Description

Technical Field

[0001] The present disclosure generally relates to methods for recycling polyurethane materials. More specifically, the present disclosure relates to methods for recycling polyurethane materials that contain moieties capable of being decomposed by acid hydrolysis. Background Art

[0002] Polyurethane materials are used in numerous applications across various industries due to their robustness, longevity, and ability to be tailored to specific end-use applications. Furthermore, polyurethane materials are more environmentally friendly than some plastic materials used in industry due to their recyclability compared to those plastic technology solutions and their use in energy-efficient end-use applications such as insulation (e.g., building and pipe insulation) and lightweighting of components.

[0003] Although polyurethane materials can be recycled using some techniques known in the art, such as mechanical recycling and chemical recycling (e.g., glycolysis, hydrolysis, pyrolysis, and hydrogenation), the polyurethane industry still needs to develop other methods to facilitate the recycling of polyurethane materials and thereby reduce the total amount of energy, time, machinery, and reagents required to recycle such materials.

[0004] Details

[0005] As used herein, unless expressly specified otherwise, all numbers, such as those expressing values, ranges, amounts, or percentages, may be read as if preceded by the word "about," even if the term does not expressly appear. The plural encompasses the singular and vice versa.

[0006] As used herein, "plurality" refers to two or more, while the term "number" refers to one or an integer greater than one.

[0007] As used herein, "including" and similar terms mean "including but not limited to."

[0008] As used herein, unless otherwise indicated, "molecular weight" refers to weight average molecular weight (Mw) as determined by gel permeation chromatography.

[0009] When any numerical range is mentioned, the range is understood to include every number and / or fraction between the minimum and maximum values of the range. For example, a range of "1 to 10" is intended to include all subranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0010] Unless otherwise indicated herein, a reference to any compound is intended to include any isomers (eg, stereoisomers) of that compound. Summary of the Invention

[0011] Polyurethane materials can be recycled using a variety of techniques known to those skilled in the art. As mentioned above, those techniques include both mechanical recycling and chemical recycling. Although recycling techniques can be effective in utilizing polyurethane materials from waste, the present disclosure is intended to address the inherent drawbacks of those techniques.

[0012] Thus, in one embodiment, the present disclosure relates to a method for recycling a polyurethane material, wherein the polyurethane material comprises a moiety (e.g., in its polymer backbone) capable of being decomposed / degraded by acid hydrolysis. Examples of suitable moieties capable of being acid hydrolyzed include esters, amides, thioesters, imides, carbamates, acetals, alkyl chlorides, nitrates, lactams, lactones, sulfonamides, or combinations thereof. Specifically, the method comprises: contacting the polyurethane material with an acid solution to decompose at least a portion of the polyurethane material into a recovered feedstock composition comprising: (i) a degradation compound; and introducing an acetoacetylated polyol into the recovered feedstock composition, and reacting the acetoacetylated polyol with component (i) (i.e., the degradation compound) to form (zz) a polyol compound.

[0013] The acid solution used in the acidolysis process can comprise any acid compound, as long as it has a pH less than or equal to about 2. Operable suitable acid compound comprises mineral acid, keto acid (for example sulfonic acid, carboxylic acid), acid (for example methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, sulfuric acid, nitric acid and hydrochloric acid) with negative pKa or their combination. In certain embodiments, acid solution can comprise other components except acid compound. These components can comprise water and / or (yy) one or more polyol compounds, such as described in further detail below. In certain embodiments, acid compound and component (yy) are miscible. As used in this article, " miscible " relevant with acid compound refers to that acid compound and component (yy) form uniform mixture.

[0014] Although it is desirable to immerse the entire polyurethane material to be decomposed in the acid solution, there are also embodiments in which only a portion of the polyurethane material is contacted with the acid solution. In these embodiments, the remaining portion of the polyurethane material (i.e., the portion not in contact with the acid solution) is not decomposed. In other words, the present disclosure also contemplates partial recycling of the polyurethane material.

[0015] There are also various methods to promote the acidolysis process and ultimately decompose the polyurethane material into various components including the recycled raw material composition. For example, once immersed in the acid solution, the polyurethane material can be stirred using techniques known in the art. In addition, heat can be applied to one or both of the acid solution and the polyurethane material to promote the acidolysis process. For example, the acid solution in which the polyurethane material is immersed can be heated to a temperature of 60°C to 100°C. Another technique that can be used to promote the decomposition of the polyurethane material is to place the acid solution and the polyurethane material in a container and place the polyurethane material immersed in the acid solution under vacuum. It should be understood that one or more of the techniques described in this paragraph can be used (alone or in combination) to promote the decomposition of the polyurethane material. Although the total time required to decompose the polyurethane material into the recycled raw material composition can vary depending on many factors such as the thickness of the polyurethane material, in certain embodiments, the entire decomposition process can take approximately four (4) to five (5) hours.

[0016] As a result of the acid hydrolysis process, the polyurethane material disclosed herein is decomposed into a raw material composition comprising component (i) and optionally other raw materials for forming the polyurethane material. Depending on the reactive components used to form the polyurethane material, component (i) may include an aldehyde compound, a ketone compound, or a combination thereof. In addition to component (i), in certain embodiments, the raw material composition may also include other components that can be used as raw materials / reactive components for forming other materials. These other components may include: (ii) a hydroxyl-terminated urethane compound, (iii) a hydroxyl-containing compound, (iv) an auxiliary compound, or a combination thereof.

[0017] Component (ii) has a molecular weight less than that of the polyurethane material. Depending on the location of the acid-degradable moiety in the polymer backbone of the polyurethane material, the molecular weight of component (ii) may be from 1,000 to 6,000 (e.g., from 1,500 to 5,000, or from 2,000 to 3,000). In certain embodiments, depending on the polymer structure of the polyurethane material, component (ii) may have a linear or branched structure.

[0018] Although components (iii)-(iv) depend on the type of raw materials initially used to form the polyurethane material and whether those raw materials react with other components during polymerization, examples of materials that can be recycled as components (iii)-(iv) include the various isocyanate-reactive compounds and / or auxiliary compounds described below. In certain embodiments, component (iii) and component (yy) may be the same or different types of polyols. Recycled materials, such as recycled polyol compounds, can then be used as raw materials to form other materials.

[0019] As mentioned above, the raw material composition includes components (i)-(iv). However, in some cases, it is undesirable to have component (i) because it can have an adverse effect on the property of the material formed by one or more components of the raw material composition. In that case, acetoacetylated polyol can be introduced into the raw material composition for recovery. Acetoacetylated polyol compound reacts with component (i) to form (zz) polyol compound. In certain embodiments, component (zz) is a polyol compound different from components (iii) and (yy). Although component (zz) can have any molecular weight greater than 50, in certain embodiments, component (zz) has a molecular weight of 100 to 5000 and comprises at least one reactive methylene structural part to component (i).

[0020] The disclosed method can convert certain polyurethane materials into raw material compounds that can be used as reactive components to form other materials, such as other types of polyurethane materials. This method of recycling the original polyurethane material can significantly reduce the amount of polyurethane material that ultimately ends up in landfills. In addition, the total cost of manufacturing materials from the recycled raw materials disclosed herein can potentially be lower than the cost of manufacturing the same materials from non-recycled raw materials.

[0021] Polyurethane materials that are easily acid-decomposed

[0022] The polyurethane material recovered in the disclosed method is a material comprising structural moieties capable of decomposition by acid hydrolysis. The polyurethane material can be formed using techniques well known in the art, but generally, the polyurethane material is the reaction product of an isocyanate compound and an isocyanate-reactive compound. Depending on the specific end-use application, the polyurethane material may also contain other reactive components (e.g., water) or other auxiliary components, which are described in further detail below.

[0023] Isocyanate compounds

[0024] One or more isocyanate compounds can be used as reactive ingredients to form the polyurethane materials disclosed herein. In some embodiments, the isocyanate compound is a polyisocyanate compound. Suitable polyisocyanate compounds that can be used include aliphatic, araliphatic and / or aromatic polyisocyanates. Isocyanate compounds generally have R—(NCO) xStructure, wherein x is at least 2 and R comprises an aromatic, aliphatic or combined aromatic / aliphatic group. Non-limiting examples of suitable polyisocyanates include diphenylmethane diisocyanate ("MDI") type isocyanates (e.g., 2,4'MDI, 2,2'MDI, 4,4'MDI or mixtures thereof), mixtures of MDI and their oligomers (e.g., polymeric MDI or "crude" MDI), and reaction products of polyisocyanates with components containing isocyanate-reactive hydrogen atoms (e.g., polymeric polyisocyanates or prepolymers). Thus, suitable isocyanate compounds that may be used include DNR isocyanate, 2185 isocyanate, M isocyanate and 1840 isocyanate, or a combination thereof. and Isocyanate compounds are available from Huntsman International LLC.

[0025] Other examples of suitable isocyanate compounds include toluene diisocyanate ("TDI") (e.g., 2,4TDI, 2,6TDI, or a combination thereof), hexamethylene diisocyanate ("HMDI" or "HDI"), isophorone diisocyanate ("IPDI"), butylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanatocyclohexylmethane (e.g., 4,4'-diisocyanatodicyclohexylmethane), isocyanatomethyl-1,8-octane diisocyanate, tetramethylxylene diisocyanate ("TMXDI"), 1,5-naphthalene diisocyanate ("NDI"), p-phenylene diisocyanate ("PPDI"), 1,4-cyclohexane diisocyanate ("CDI"), toluidine diisocyanate ("TODI"), or a combination thereof. Modified polyisocyanates containing isocyanurate, carbodiimide, or uretonimine groups may also be used as component (i).

[0026] Blocked polyisocyanates can also be used as isocyanate compounds, as long as the reaction product has a deblocking temperature that is lower than the temperature at which the isocyanate compound reacts with the isocyanate-reactive compound. Suitable blocked polyisocyanates may include the reaction products of (a) a phenol or oxime compound and a polyisocyanate, or (b) a polyisocyanate and an acidic compound such as benzyl chloride, hydrochloric acid, thionyl chloride, or a combination thereof. In certain embodiments, the polyisocyanate may be blocked with the above-mentioned compounds and then introduced into the reactive ingredients / components for forming the polyurethane material.

[0027] Mixtures of isocyanates, for example mixtures of TDI isomers (for example mixtures of the 2,4-TDI and 2,6-TDI isomers) or mixtures of diisocyanates and higher polyisocyanates obtained by phosgenation of aniline / formaldehyde condensates, can also be used as isocyanate compounds.

[0028] In some embodiments, the isocyanate compound is liquid at room temperature. The mixture of isocyanate compounds can be produced according to any technology known in the art. If necessary, the isomer content of diphenyl-methane diisocyanate can be within the desired range by technology well known in the art. For example, one technique for changing the isomer content is to add monomeric MDI (e.g., 2,4-MDI) to an MDI mixture containing polymeric MDI (e.g., MDI comprising 30% to 80% w / w of 4,4'-MDI and the remainder of the MDI comprising MDI oligomers and MDI homologues) above the desired amount.

[0029] Isocyanate-reactive compounds

[0030] One or more isocyanate-reactive compounds can be used as reactive ingredients to form the polyurethane materials disclosed herein. Any known organic compound containing at least two isocyanate-reactive moieties per molecule can be used as the isocyanate-reactive compound. Polyol compounds or mixtures thereof that are liquid at 25° C., have a molecular weight of 60 to 10,000 (e.g., 300 to 10,000, or less than 5,000), a nominal hydroxyl functionality of at least 2, and a hydroxyl equivalent weight of 30 to 2,000 (e.g., 30 to 1,500, or 30 to 800) can be used as the isocyanate-reactive compound component.

[0031] Examples of suitable polyols that can be used as isocyanate-reactive compounds include polyether polyols, such as those made by adding alkylene oxides to initiators, each molecule of which contains 2 to 8 active hydrogen atoms. In some embodiments, the initiator includes ethylene glycol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, sucrose, ethylenediamine, ethanolamine, diethanolamine, aniline, toluenediamine (e.g., 2,4-toluenediamine and 2,6-toluenediamine), polymethylenepolyphenylene polyamines, N-alkylphenylenediamines, o-chloroaniline, p-aminoaniline, diaminonaphthalene, or a combination thereof. Suitable alkylene oxides that can be used to form polyether polyols include ethylene oxide, propylene oxide, and butylene oxide, or a combination thereof.

[0032] Other suitable polyol compounds that can be used for isocyanate-reactive compounds include Mannich polyols with a nominal hydroxyl functionality of at least 2 and at least one secondary or tertiary amine nitrogen atom per molecule. In some embodiments, Mannich polyols are condensates of aromatic compounds, aldehydes, and alkanolamines. For example, Mannich condensates can be prepared by condensing one or both of phenol and alkylphenols with formaldehyde and one or more of monoethanolamine, diethanolamine, and diisopropanolamine. In specific embodiments, Mannich condensates are condensates of phenol or nonylphenol with formaldehyde and diethanolamine. Mannich condensates can be made by any known method. In some embodiments, Mannich condensates are used as initiators for alkoxylation. Any alkylene oxide (such as those mentioned above) can be used for alkoxylating one or more Mannich condensates. When polymerization is complete, Mannich polyols contain primary and / or secondary hydroxyl groups bound to aliphatic carbon atoms.

[0033] In certain embodiments, the polyol used as the isocyanate-reactive compound is a polyether polyol comprising propylene oxide ("PO"), ethylene oxide ("EO"), or a combination of PO and EO groups or moieties in the polymeric structure of the polyol. These PO and EO units may be arranged randomly or in blocks throughout the polymeric structure. In certain embodiments, the EO content of the polyol is from 0 to 100 wt % (e.g., from 50 wt % to 100 wt %) based on the total weight of the polyol. In some embodiments, the PO content of the polyol is from 100 to 0 wt % (e.g., from 100 wt % to 50 wt %) based on the total weight of the polyol. Thus, in some embodiments, the EO content of the polyol may be from 99 wt % to 33 wt % of the polyol, while the PO content may be from 1 wt % to 66 wt % of the polyol. Furthermore, in some embodiments, the EO and / or PO units may be located at the ends of the polyol polymeric structure or at the interior of the polyol polymeric backbone structure. Suitable polyether polyols include poly(oxyethyleneoxypropylene) diols and triols obtained by sequentially adding propylene oxide and ethylene oxide to difunctional or trifunctional initiators known in the art. In certain embodiments, the isocyanate-reactive compound is a diol or triol as described above, or alternatively, the isocyanate-reactive compound may comprise a mixture of these diols and triols.

[0034] The above-mentioned polyether polyols also include the reaction products of ethylene oxide and another epoxide (e.g., propylene oxide) obtained by polymerization in the presence of a multifunctional initiator (such as water and a low molecular weight polyol). Suitable low molecular weight polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, cyclohexanedimethanol, resorcinol, bisphenol A, glycerol, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, or a combination thereof.

[0035] Polyester polyols useful as isocyanate-reactive compounds include polyesters having a linear polymeric structure and a number average molecular weight (Mn) of about 500 to about 10,000 (e.g., preferably about 700 to about 5,000, or 700 to about 4,000) and an acid number generally less than 1.3 (e.g., less than 0.8). Molecular weight is determined by terminal functional group analysis and is related to the number average molecular weight. Polyester polymers can be produced using techniques known in the art, such as: (1) esterification of one or more diols with one or more dicarboxylic acids or anhydrides; or (2) transesterification (i.e., reaction of one or more diols with dicarboxylic acid esters). Generally, a molar excess of diol to acid of more than one mole is preferred so that linear polymeric chains with terminal hydroxyl groups are obtained. Suitable polyester polyols also include various lactones, typically made from caprolactone and a difunctional initiator such as diethylene glycol. The dicarboxylic acid of the desired polyester can be aliphatic, alicyclic, aromatic, or a combination thereof. Suitable dicarboxylic acids that can be used alone or in a mixture generally have 4 to 15 carbon atoms in total, including succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid or a combination thereof. Anhydrides of the above-mentioned dicarboxylic acids (such as phthalic anhydride, tetrahydrophthalic anhydride or a combination thereof) can also be used. In some embodiments, adipic acid is a preferred acid. The glycol for forming suitable polyester polyols can include aliphatic and aromatic glycols with 2 to 12 carbon atoms in total. The example of this glycol includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propylene glycol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, or a combination thereof.

[0036] Additional examples of suitable polyols that can be used as isocyanate-reactive compounds include hydroxyl-terminated polythioethers, polyamides, polyesteramides, polycarbonates, polyacetals, polyolefins, polysiloxanes, and simple glycols such as ethylene glycol, butanediol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and mixtures thereof.

[0037] In certain embodiments, the isocyanate reactive compound for forming polyurethane material is the polyol comprising acetal structure portion, orthoester structure portion or their combination.If in polyol, the acetal structure portion is needed, the reactive mixture comprising polyol compound and divinyl ether compound can be used to form the polyol containing acetal so.If in polyol, the orthoester structure portion is needed, the reactive mixture comprising polyol compound and diketene acetal compound can be used to form the polyol containing orthoester structure portion.If the polyol comprising acetal structure portion and orthoester structure portion is needed, the reactive mixture comprising polyol compound, divinyl ether compound and diketene acetal compound can be used to form the polyol containing acetal and orthoester so. Suitable polyol compounds that can be used as components for forming polyols containing acetal and / or orthoester moieties include any of the various polyols described above, while: (a) suitable divinyl ether compounds include tri(ethylene glycol) divinyl ether, di(ethylene glycol) divinyl ether, 1,4-butanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether; and (b) suitable diketene acetal compounds include 3,9-diethylene-2,4,8,10-tetraoxaspiro[5.5]undecane, 3,9-dimethylene-2,4,8,10-tetraoxaspiro[5.5]undecane, or combinations thereof. In some embodiments, the polyol containing acetal and / or orthoester is formed by reacting a molar excess of component (a) with component (b) (optionally in the presence of a catalyst).

[0038] water

[0039] In addition to the isocyanates and isocyanate-reactive compounds described above, the reactive compositions used to form the polyurethane materials disclosed herein may include water. The addition of water to the reactive mixture will depend on the ultimate end-use application of the polyurethane material. Although water can be considered an isocyanate-reactive compound, for purposes of this disclosure, water should be considered a separate component from the isocyanate compound. In other words, depending on the specific end-use application, the reactive mixture used to form the polyurethane material may include both isocyanate-reactive compounds and water.

[0040] Any type of purified water can be used as the reactive ingredient, as long as it has been filtered or processed to remove impurities. Suitable types of water include distilled water and water that has been purified by one or more of the following methods: capacitive deionization, reverse osmosis, carbon filtration, microfiltration, ultrafiltration, ultraviolet oxidation, and / or electrodeionization.

[0041] Auxiliary compounds / additives

[0042] The reactive mixture used to form the polyurethane materials disclosed herein may contain one or more auxiliary compounds / additives that are conventionally used in the manufacture of polyurethane materials. Auxiliary compounds can be added directly to the reactive composition used to form the polyurethane material and are generally selected to impart certain qualities to the reactive composition and / or the polyurethane material formed therefrom.

[0043] Suitable additives that can be added to or otherwise used with the reactive composition include surfactants, flame retardants, smoke suppressants, crosslinking agents, viscosity reducers, infrared opacifiers, cell size reducing compounds, pigments, fillers, reinforcing agents, mold release agents, antioxidants, dyes, pigments, antistatic agents, biocides, blowing agents, or combinations thereof.

[0044] Examples of suitable flame retardants that can be used in the reactive composition include: organophosphorus compounds (e.g., organophosphates, phosphites, phosphonates, polyphosphates, polyphosphites, polyphosphonates), ammonium polyphosphates (e.g., triethyl phosphate, ethyl diethylphosphonate, and tris(2-chloropropyl) phosphate); and halogenated flame retardants (e.g., tetrabromophthalates and chlorinated paraffins).

[0045] In certain embodiments, the surfactant used in the reactive composition may include one or more silicone-based or non-silicone-based surfactants. These surfactants are generally used to control the size of the cells formed when the foam composition reacts to form the polyurethane foam product, thereby allowing control over the internal cell structure of the foam product. In certain embodiments, foams containing a uniform set of small cells (e.g., <300 μm) are desirable because they exhibit excellent physical properties (e.g., compressive strength and thermal conductivity). In addition, the above-mentioned surfactants also help stabilize the internal cells, thereby ensuring that the cells do not collapse when the composition reacts to form the polyurethane foam product.

[0046] Examples of suitable silicone surfactants that can be used in the reactive composition include polyorganosiloxane polyether copolymers and polysiloxane polyoxyalkylene block copolymers (e.g., L-5345, L-5440, L-6100, L-6642, L-6900, L-6942, L-6884, L-6972 from Momentive and DC-193, DC5357, Si3102, Si3103, Tegostab 8490; 8496, 8536; 84205; 84210; 84501; 84701, 84715 from Evonik Industries AG). Other silicone surfactants that can be used are also disclosed in U.S. Pat. No. 8,906,974 and U.S. Pat. Pub. No. US 2016 / 0311961.

[0047] Examples of suitable non-silicone surfactants that can be used in the reactive composition include nonionic, anionic, cationic, amphoteric, semipolar, and zwitterionic organic surfactants. Suitable nonionic surfactants include phenol alkoxylates and alkylphenol alkoxylates (e.g., ethoxylated phenol and ethoxylated nonylphenol, respectively). Other useful non-silicone nonionic surfactants include LK-443 (available from Evonik Industries AG) and VORASURF 504 (available from Dow Chemicals).

[0048] Examples of other suitable additives that can be used in the reactive composition include triethanolamine and glycerol crosslinkers; propylene carbonate and 1-methyl-2-pyrrolidone viscosity reducers; carbon black, titanium dioxide, and metallic flake infrared opacifiers; inert, insoluble fluorinated compounds and perfluorinated cell size reducing compounds; calcium carbonate filler; glass fiber and / or ground foam waste reinforcement; zinc stearate mold release agent; butylated hydroxytoluene antioxidant; azo / diazo dyes and phthalocyanine pigments.

[0049] As described above, the reactive compositions used to form the polyurethane materials disclosed herein can include one or more catalysts. These catalysts can include amine-based catalyst compounds, non-amine-based catalyst compounds, or combinations thereof.

[0050] Examples of suitable amine-based catalyst compounds that can be used in the reactive composition include compounds containing at least one tertiary group, including: bis(2-dimethylaminoethyl)ether (e.g. ZF-20 catalyst), N,N,N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether (e.g. ZF-10 catalyst), N-(3-dimethylaminopropyl)-N,N-diisopropanolamine (e.g. DPA catalyst), N,N-dimethylethanolamine (e.g. DMEA catalyst), a blend of N,N-dimethylethanolamine and ethylenediamine (e.g. TD-20 catalyst), N,N-dimethylcyclohexylamine (e.g. DMCHA catalyst), N-methyldicyclohexylamine (e.g. POLYCAT 12 available from Evonik Industries AG), benzyldimethylamine (e.g. BDMA catalyst), pentamethyldiethylenetriamine (e.g. PMDETA catalyst), N,N,N',N",N"-pentamethyldipropylenetriamine (e.g. ZR-40 catalyst), N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine (e.g. ZR-50 catalyst), N'-(3-(dimethylamino)propyl-N,N-dimethyl-1,3-propanediamine (e.g. Z-130 catalyst), 2-(2-dimethylaminoethoxy)ethanol (e.g. ZR-70 catalyst), N,N,N'-trimethylaminoethyl-ethanolamine (e.g. Z-110 catalyst; DABCO T), N-ethylmorpholine (e.g. NEM catalyst), N-methylmorpholine (e.g. NMM catalyst), 4-methoxyethylmorpholine, N,N'-dimethylpiperazine (e.g. DMP catalyst), 2,2'-dimorpholine diethyl ether (e.g. DMDEE catalyst), 1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine (e.g. TR-90 catalyst), 1-propylamine, 3-(2-(dimethylamino)ethoxy); substituted imidazoles (e.g., 1-methylimidazole, 1,2-dimethylimidazole (e.g., DABCO 2040 available from Evonik Industries AG and TOYOCAT DM70 available from Tosho Corporation), 1-methyl-2-hydroxyethylimidazole (e.g., N-(3-aminopropyl)imidazole, 1-n-butyl-2-methylimidazole, 1-isobutyl-2-methylimidazole, N,N'-dimethylpiperazine), disubstituted piperazines (e.g., aminoethylpiperazine, N,N',N'-trimethylaminoethylpiperazine, or bis(N-methylpiperazine)urea), N-methylpyrrolidine and substituted methylpyrrolidines (e.g., 2-aminoethyl-N-methylpyrrolidine or bis(N-methylpyrrolidine)ethylurea), 3-dimethylaminopropylamine, N,N,N",N"-tetramethyldipropylenetriamine, Tetramethylguanidine, 1,2-bis-diisopropyl alcohol, or a combination thereof. Other examples of amine catalysts include N-alkylmorpholine, N-butylmorpholine and dimorpholine diethyl ether, N,N'-dimethylaminoethanol, N,N-dimethylaminoethoxyethanol, bis(dimethylaminopropyl)-amino-2-propanol, bis(dimethylamino)-2-propanol, bis(N,N-dimethylamino)ethyl ether, N,N,N'-trimethyl-N'-hydroxyethyl-bis(aminoethyl) ether, N,N-dimethylaminoethyl-N'-methylaminoethanol, tetramethyliminobispropylamine, N,N-dimethyl-p-toluidine, diethyltoluenediamine (Ethacure 100), 3,5-dimethylthio-2,4-toluenediamine (Ethacure 300); poly(oxypropylene)triamine (e.g. T-5000 catalyst) reactive acid-blocked catalysts (e.g., phenolates of 1,8-diazabicyclo(5,4,0)undecene-7, LED and ZF brand catalyst), or a combination thereof. The catalysts are all available from Huntsman Corporation.

[0051] Examples of suitable non-amine based catalyst compounds that can be used in the reactive composition include organometallic compounds (e.g., organic salts of transition metals such as titanium, iron, nickel), post-transition metals (e.g., zinc, tin, and bismuth), alkali metals (e.g., lithium, sodium, and potassium), alkaline earth metals (e.g., magnesium and calcium), ferric chloride, ferric acetylacetonate, zinc salts of carboxylic acids, zinc 2-ethylhexanoate, stannous chloride, stannic chloride, tin salts of carboxylic acids, dialkyltin salts of carboxylic acids, tin(II) 2-ethylhexanoate, dibutyltin dilaurate (e.g., DABCO T-12 available from Evonik Industries AG), dimethyltin dimercaptide (e.g., FOMREZ UL-22 available from Momentive Performance Materials Inc.), bismuth(III) carboxylates (e.g., bismuth 2-ethylhexanoate), bismuth neodecanoate (DABCO MB-20 available from Evonik Industries AG), and bismuth(III) carboxylates. AG), bismuth pivalate, bismuth-based catalysts (e.g., compounds identified in U.S. Patent Publication No. 016 / 020888), 1,1′,1″,1″-(1,2-ethanediyldiamino)tetrakis[2-propanol] neodecanoate complex (e.g., BICAT 8840 available from Shepherd Chemicals Co.), 2,2′,2″,2″′-(1,2-ethanediyldiamino)tetrakis[ethanol] neodecanoate complex (e.g., BICAT 8842 available from Shepherd Chemicals Co.), K-KAT XC-C227 bismuth salt (available from King Industries), sodium acetate, sodium N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate (e.g., TR52 catalyst), bismuth 2-ethylhexanoate, or a combination thereof.

[0052] In certain embodiments, the reactive composition for making the polyurethane may include a trimerization catalyst. Suitable trimerization catalysts include potassium salts of carboxylic acids (e.g., potassium acetate, potassium pivalate, potassium octoate, potassium triethylacetate, potassium neoheptanoate, potassium neooctoate), quaternary ammonium carboxylates (e.g., (2-hydroxypropyl)trimethylammonium 2-ethylhexanoate ("TMR"), (2-hydroxypropyl)trimethylammonium formate ("TMR-2"), tetramethylammonium pivalate, tetramethylammonium triethylacetate, TOYOCAT TRX (available from Tosoh, Corp.), or combinations thereof.

[0053] As described above, the reactive composition may include one or more blowing agents. Although water can be used as a blowing agent in the reactive composition, other blowing agents that can be used in the reactive composition (in combination with or in place of water) include haloolefin ("HFO") compounds. Examples of suitable HFO compounds that can be used in the reactive composition include hydrohaloolefins such as trifluoropropenes, tetrafluoropropenes (e.g., tetrafluoropropene (1234)), pentafluoropropenes (e.g., pentafluoropropene (1225), chlorotrifluoropropenes (e.g., chlorotrifluoropropene (1233)), chlorodifluoropropenes, chlorotrifluoropropenes, chlorotetrafluoropropenes, hexafluorobutenes (e.g., hexafluorobutene (1336)), or combinations thereof. In certain embodiments, the tetrafluoropropene, pentafluoropropene, and / or chlorotrifluoropropene compounds used as component (vi) have no more than one fluorine or chlorine substituent attached to the terminal carbon atom of the unsaturated carbon chain (e.g., 1,3,3 ,3-tetrafluoropropene (1234ze), 1,1,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene (1225ye), 1,1,1-trifluoropropene, 1,2,3,3,3-pentafluoropropene, 1,1,1,3,3-pentafluoropropene (1225zc), 1,1,2,3,3-pentafluoropropene (1225yc), (Z)-1,1,1,2,3-pentafluoropropene (1225yez), 1-chloro-3,3,3-trifluoropropene (1233zd), 1,1,1,4,4,4-hexafluorobut-2-ene (1336mzzm), or a combination thereof.

[0054] Other blowing agents that can be used in combination with the above-mentioned HFOs include air, nitrogen, carbon dioxide, hydrofluorocarbons ("HFCs"), alkanes, olefins, monocarboxylates, ketones, ethers, or combinations thereof. Suitable HFCs include 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), or combinations thereof. Suitable alkanes and olefins include n-butane, n-pentane, isopentane, cyclopentane, 1-pentene, or combinations thereof. Suitable monocarboxylates include methyl formate, ethyl formate, methyl acetate, or combinations thereof. Suitable ketones and ethers include acetone, dimethyl ether, or combinations thereof.

[0055] Acetoacetylated polyols

[0056] As described above, the methods disclosed herein utilize acetoacetylated polyol compounds. In certain embodiments, the acetoacetylated polyol is the reaction product of an acetoacetyl-functional monomer and a polyether polyol compound, such as the polyether polyol compounds listed above. Suitable acetoacetyl-functional monomers that can be used include t-butyl acetoacetate, benzyl acetoacetate, di-t-butyl 1,3-acetonedicarboxylate, or combinations thereof.

[0057] In certain embodiments, the acetoacetylated polyol comprises up to 40% acetoacetyl functional groups based on the available hydroxyl groups in the acetoacetylated polyol. In other embodiments, the acetoacetylated polyol may have a molecular weight of 100 to 6000 (e.g., 500 to 5000, 1000 to 3000, 1500 to 2500).

[0058] Change

[0059] Although specific embodiments of the present disclosure have been described in detail, those skilled in the art will appreciate that various changes and substitutions may be made to these details in light of the overall teachings of this disclosure. Therefore, the specific arrangements disclosed are for illustrative purposes only and are not intended to limit the scope of the disclosure, which is to be given the full breadth of the appended claims and any and all equivalents thereof. Therefore, any of the features and / or elements listed above may be combined with each other in any combination and still fall within the scope of this disclosure.

[0060] The methods disclosed herein are further illustrated by the following examples, in which parts are by weight unless otherwise indicated. Example

[0061] Materials / compounds used in the examples:

[0062] Additive 1: SAG 47 silicone-based defoamer, available from Momentive Performance Materials Inc.

[0063] Additive 2: NIAX L 3001 surfactant, available from Momentive Performance Materials Inc.

[0064] Additive 3: TEGOSTAB B8409VE surfactant, available from Evonik Industries AG

[0065] Additive 4: TEGOSTAB B 8466 surfactant, available from Evonik Industries AG

[0066] Catalyst 1: TD 33A amine catalyst, available from Huntsman Corporation

[0067] Catalyst 2: Amine catalyst Jeffcat DPA

[0068] Catalyst 3: ZR-10 catalyst, available from Huntsman Corporation

[0069] Catalyst 4: ZR-50 catalyst, available from Huntsman Corporation

[0070] DVE-3: Tri(ethylene glycol) divinyl ether

[0071] Isocyanate 1: Polymeric MDI

[0072] Isocyanate 2: MDI prepolymer

[0073] DMCHA: N,N-dimethylcyclohexylamine, available from Huntsman Corporation

[0074] FX 31-167: Polyether polyol, available from Huntsman Corporation

[0075] 30-650: Polyoxypropylene triol initiated polyol, available from Huntsman Corporation

[0076] PPG-400: Polyether polyol, available from Huntsman Corporation

[0077] PPG 230: Polyether polyol, available from Huntsman Corporation

[0078] KOH: potassium hydroxide

[0079] p-TSA: p-toluenesulfonic acid

[0080] Polyol 1: Hydrolyzable polyol

[0081] Polyol 2: Hydrolyzable polyol

[0082] Polyol 3: Ethylene glycol

[0083] t-BAA: tert-butyl acetoacetate

[0084] t-Butanol: tert-butyl alcohol

[0085] Preparation and degradation of hydrolyzable polyols and polyurethane materials

[0086] Example 1:

[0087] About 291.7 g (1.45 equivalents) of PPG-400 was dried overnight and the residual water was removed by molecular sieve. PPG-400 was added to a four-necked round bottom flask equipped with a nitrogen inlet, stirring shaft, thermocouple and addition funnel. A catalytic amount (0.1 g) of p-toluenesulfonic acid monohydrate was added and the mixture was heated to 40°C with stirring to dissolve p-TSA. 110.0 g (1.09 equivalents) of DVE-3 was placed in the addition funnel and the dropwise addition of DVE-3 was started with stirring. The reaction started immediately after the addition of DVE-3 was started. 30 minutes after the addition of DVE-3 was completed, 0.45 g of DMCHA was used to neutralize p-TSA to prevent premature and unnecessary hydrolysis of the polyol. The reaction product was slightly yellow, had a viscosity of 630 cps and an Ohv# of 76.

[0088] The polyol component and the isocyanate component were mixed with each other by high-speed mixing and then transferred to the mold cavity for curing according to mixing specification 1. The isocyanate index was kept at 135 and the reaction mixture was cured at 120° C. for 20 minutes to obtain a soft elastic polyurethane material.

[0089]

[0090] The average Ohv of the polyol blend is 78 mg KOH / g

[0091] In a 2 L round bottom flask equipped with a condenser, nitrogen inlet and overhead stirrer, about 42 g of PU material was added to a mixture of PPG 230 and water (250 g each) and 20 g p-TSA were prepared in a solution. The solution was heated to 60°C under stirring. After 4 hours, a solution containing degraded polyol, acid, water and A clear solution of PPG 230. 50 g of 0.5 N KOH solution was added to the solution to neutralize the acid in the solution, and then the water in the polyol system was removed by vacuum stripping at 40°C.

[0092] Example 2:

[0093] The process is carried out as in Example 1, but using a higher functional polyol to produce a high functional hydrolyzable polyol.

[0094] 27.0 g (0.134 eq.) of freshly dried PPG-400 and 45g (0.134 equivalent) FX 31-167 and a catalytic amount of p-TSA (0.1 g) were added to a 200 mL Erlenmeyer flask equipped with a magnetic stirrer. The solution was heated to 40°C with stirring until the acid was completely dissolved in the polyol blend. The reaction was initiated by adding 20.2 g (0.2 equivalents) of pre-dried DVE-3 via the addition funnel described in Example 1. After neutralization of the residual acid in the product mixture, a clear, viscous liquid product with a viscosity of 5321 cps and a hydroxyl number of 59 was recovered.

[0095] Starting from mixing specification 2, the polyol component and the isocyanate component are mixed with each other by high-speed mixing and then transferred to a container to produce a flexible foam polyurethane material. The isocyanate index is maintained at 80 to achieve a flexible foam polyurethane material.

[0096]

[0097] The average Ohv of the polyol mixture is 213 mg KOH / g

[0098] The degradation process of the PU flexible foam was similar to that of Example 1. However, the flexible PU foam was only partially degraded (about 75%) in the solution. As can be seen, the hard lumps formed in the polyurethane foam by the reaction of urea and ethylene glycol with isocyanate did not dissolve during this process.

[0099] Preparation of acetoacetylated polyols

[0100] Example 3:

[0101] 162.01g 30-650 and 118.62 g (40% acetoacetylation amount calculated based on available hydroxyl groups) of t-BAA were charged to a 2000 mL three-necked round bottom flask equipped with a nitrogen inlet, a thermocouple with a temperature controller, a condenser with a collection flask, and an overhead stirrer. The acetoacetylation reaction was carried out under a nitrogen flow at 140°C. After 4 hours, 30.7 g of t-butyl alcohol was collected. At this time, no more distillate was produced and the reaction was terminated and deemed complete. The theoretical amount of t-butyl alcohol that should be distilled is 55.49 g. The product was degassed in a vacuum oven at 70°C for 2 hours to remove any other volatiles. Acetoacetylation of the polyol reduces viscosity because bulky side groups are included, which increases the separation between the polymer chains.

[0102] Then acetoacetylated polyol is blended with the degradation polyol system that contains free aldehyde.Blending is based on the 2:1 mol ratio of the active methylene group existing in the acetoacetylated polyol and the free acetaldehyde existing in the degradation polyol, because two moles of active methylene groups are needed to remove one mole of acetaldehyde.About 50g of polyol that contains 750ppm (0.001 mole) free aldehyde is blended with about 1g of acetoacetylated polyol (>0.02 mole) to remove aldehyde from solution.After 15 days, the free aldehyde content in the solution is reduced to lower than 10ppm.

Claims

1. A method for recovering a polyurethane material, wherein the polyurethane material comprises a structural portion capable of being decomposed by acid hydrolysis, the method comprising: contacting the polyurethane material with an acid solution to decompose at least a portion of the polyurethane material into a recovered feedstock composition comprising: (i) a degradation compound; and introducing an acetoacetylated polyol into the recovered feedstock composition and reacting the acetoacetylated polyol with component (i) to form a (zz) polyol compound, Wherein component (i) is an aldehyde compound, a ketone compound or a combination thereof.

2. The method of claim 1, wherein the recovered feedstock composition further comprises: (ii) a hydroxyl-terminated urethane compound, (iii) a hydroxyl-containing compound different from component (ii), (iv) an auxiliary compound, or a combination thereof.

3. The method according to claim 1, wherein the acid solution comprises an acid compound, water and (yy) a polyol compound. The method according to claim 3 , wherein the acid compound has a pH of ≤ 2.

5. The method according to claim 3, wherein the acid compound is miscible with component (yy).

6. The method of claim 3, wherein the recovered feedstock composition comprises at least a portion of the acid solution that was contacted with the polyurethane material, and the method further comprises extracting water from the feedstock composition.

7. The method of claim 1, wherein the method further comprises utilizing one or more of components (i)-(iv) and (zz) as a raw material for making another material.

8. The method of claim 7, wherein the method further comprises extracting one or more of components (i)-(iv) and (zz) from the recovered feedstock composition before it is used as a feedstock.

9. The method of claim 1, wherein the method comprises immersing at least a portion of the polyurethane material in the acid solution.

10. The method according to claim 1, wherein the entire polyurethane material is immersed in the acid solution.

11. The method according to claim 1, further comprising stirring the polyurethane material during the acid hydrolysis process to promote decomposition of the polyurethane material.

12. The method of claim 1, wherein the method includes applying heat to the polyurethane material during the acid hydrolysis process to promote decomposition of the polyurethane material.

13. The method of claim 1, wherein the method comprises performing acid hydrolysis under vacuum to promote decomposition of the polyurethane material.

14. The method of claim 1, wherein the polyurethane material comprises acetal moieties in its polymer backbone.

15. The method of claim 1, wherein the polyurethane material is a reaction product of an isocyanate compound and an isocyanate-reactive compound, wherein the isocyanate-reactive compound comprises a polyol compound containing an acetal moiety, an orthoester moiety, or a combination thereof.

16. The method of claim 1 , wherein the polyurethane material is the reaction product of an isocyanate compound and an isocyanate-reactive compound, wherein the isocyanate-reactive compound is the reaction product of: (a) a polyol compound, and (b) a divinyl ether compound, wherein component (a) is in molar excess over component (b).

17. The method of claim 1, wherein the acetoacetylated polyol is the reaction product of an acetoacetyl-functional monomer and a polyether polyol compound.

18. The method of claim 1, wherein the acetoacetylated polyol comprises up to 40% acetoacetyl functional groups based on available hydroxyl groups in the acetoacetylated polyol.

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