Foaming agent composition, premixed polyether, polyurethane composition, polyurethane foam and refrigeration equipment

Abstract

The invention provides a foaming agent composition, premixed polyether polyol, a polyurethane composition, polyurethane foam and refrigeration equipment. The foaming agent composition comprises a foaming agent and a foam stabilizer, the foaming agent comprises bio-based cyclopentane and a CO2-based foaming agent, and the foam stabilizer comprises a bio-based siloxane-polyether copolymer. The environment-friendly property of the polyurethane foam can be improved.

Description

Technical Field

[0001] This application belongs to the field of polyurethane technology, and particularly relates to a foaming agent composition, a combined polyether, a polyurethane composition, a polyurethane foam, and a refrigeration device. Background Technology

[0002] Currently, polyurethane foam is commonly used for the insulation layer of refrigeration equipment. However, the blowing agents of existing polyurethane foams mostly rely on high GWP (Global Warming Potential) substances such as HFC-245fa (GWP=1030) and HFC-134a (GWP=1430). Moreover, the foam stabilizers are mostly silicone oils containing PFAS (per- and polyfluoroalkyl substances), which pose environmental residue risks and are difficult to meet environmental protection regulations. Summary of the Invention

[0003] This application provides a foaming agent composition, a combined polyether, a polyurethane composition, a polyurethane foam, and a refrigeration device to solve the problem that existing foaming agent compositions are difficult to meet environmental regulations.

[0004] In a first aspect, embodiments of this application provide a foaming agent composition comprising a foaming agent and a foam stabilizer, wherein the foaming agent comprises bio-based cyclopentane and CO2-based foaming agents, and the foam stabilizer comprises a bio-based siloxane-polyether copolymer.

[0005] Optionally, by weight, the foaming agent composition comprises 12 to 25 parts of the foaming agent and 1 to 4 parts of the foam stabilizer; and / or, the mass ratio of the bio-based cyclopentane to the CO2-based foaming agent is (8 to 12):(3 to 5); and / or, the CO2-based foaming agent comprises a dimethyl carbonate derivative, wherein the dimethyl carbonate derivative comprises one or more of diethyl carbonate, methyl ethyl carbonate, methyl vinyl carbonate, dipropyl carbonate, and dimethyl carbonate-propylene oxide copolymer.

[0006] Optionally, the bio-based siloxane-polyether copolymer is prepared by the following method: alcoholysis of vegetable oil to obtain a bio-based polyol; and copolymerization reaction of the bio-based polyol, polyether monomer, siloxane monomer and first catalyst to obtain the bio-based siloxane-polyether copolymer.

[0007] Optionally, the surface tension of the bio-based siloxane-polyether copolymer is ≤28 mN / m; and / or, the mass ratio of the bio-based polyol, the polyether monomer, and the siloxane monomer is (50~70):(20~30):(5~15), and the first catalyst accounts for 0.01%~0.1% of the total mass of the bio-based polyol, the polyether monomer, the siloxane monomer, and the first catalyst; and / or, the vegetable oil includes one or more of rapeseed oil, soybean oil, palm oil, flaxseed oil, cottonseed oil, and sunflower oil; and / or, the polyether monomer includes propylene oxide / ethane polymer, tetrahydrofuran, etc. The catalyst comprises one or more of the following: homopolymers, epichlorohydrin polymers, epichlorohydrin-ethylene oxide copolymers, and glycidyl ether polyethers; and / or, the siloxane monomer comprises one or more of octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, methyltrimethoxysilane, and vinyltriethoxysilane; and / or, the first catalyst comprises a first base catalyst or a platinum catalyst, the first base catalyst comprising one or more of potassium hydroxide and sodium hydroxide, and the platinum catalyst comprising one or more of chloroplatinic acid, platinum-vinylsiloxane complexes, platinum-cyclopentadiene complexes, and platinum-phosphine ligand complexes.

[0008] Secondly, embodiments of this application also provide a combined polyether, the combined polyether comprising a polyol composition and the above-mentioned foaming agent, wherein the polyol composition comprises a bio-based polyol.

[0009] Optionally, the bio-based polyol includes a modified starch-castor oil composite polyol and an epoxy compound grafted onto the modified starch-castor oil composite polyol, with a grafting rate of 30% to 40%.

[0010] Optionally, the bio-based polyol is prepared by the following method: starch is modified by esterification or etherification to obtain modified starch; the modified starch is dried at 100℃~110℃ for 2h-3h; castor oil is dehydrated by vacuum distillation at 110℃~120℃; the dehydrated castor oil and modified starch are mixed, a second alkali catalyst is added, the temperature is raised to 100℃~120℃, an epoxide compound is introduced, and the reaction is carried out at 0.3MPa~0.5MPa for 4h~6h; after neutralization, low-boiling substances are removed by vacuum, and the mixture is filtered to obtain the bio-based polyol.

[0011] Optionally, the epoxy compound includes one or more of propylene oxide, cyclohexane oxide, ethylene oxide, butane oxide, and phenyl glycidyl ether; and / or, the second base catalyst includes one or more of potassium hydroxide and sodium hydroxide; and / or, the modified starch is prepared by mixing starch with esters or ethers and reacting at 60°C to 90°C for 2 to 4 hours to obtain modified starch; and / or, the addition of the second base catalyst includes adding a second base catalyst and a nucleating agent, wherein the nucleating agent includes one or more of polycaprolactone, polyethylene glycol, polylactide, butylene adipate, polytrimethylene carbonate, and polycaprolactone-polyethylene glycol block copolymer.

[0012] Optionally, the bio-based polyol has a bio-based content of ≥70%, a hydroxyl value of 280mgKOH / g~320mgKOH / g, and a viscosity of 1500mPa at 25°C. s~2000mPa s.

[0013] Optionally, the modified starch is prepared by grafting starch and silane in a mass ratio of 9:1 to 11:1, with a grafting rate of 8% to 25%.

[0014] Optionally, the silane includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0015] Optionally, by weight, the polyether composition comprises 100 parts of the polyol composition; and / or, by weight, the polyol composition comprises 20-30 parts of the bio-based polyol, 10-20 parts of sorbitol polyether, 18-25 parts of o-toluene diamine polyether, 10-22 parts of sucrose-propylene glycol composite polyether, and 20-25 parts of glycerol polyether; and / or, by weight, the polyether composition further comprises 0.5-3.5 parts of water.

[0016] Optionally, by weight, the polyether complex further includes 1 to 3.5 parts of catalyst and 1 to 3 parts of viscosity modifier, wherein the catalyst includes pentamethyldiethylenetriamine, bio-based amine additive, dimethylcyclohexylamine and temperature-responsive nanocarrier, and the viscosity modifier includes bio-based esters.

[0017] Optionally, the mass ratio of the pentamethyldiethylenetriamine, the bio-based amine adjuvant, the dimethylcyclohexylamine, and the temperature-responsive nanocarrier is (0.1~6):(0.1~0.3):(0.5~7):(0.01~0.5); and / or, the bio-based amine adjuvant includes one or more of bio-based ethanolamine, chitosan-based amine adjuvants, soybean protein-based amine, bio-based propylamine, and bio-based butylamine; and / or, the temperature-responsive nanocarrier includes one or more of nano-silica, nano-titanium dioxide, poly(N-isopropylacrylamide)-based nanocarriers, chitosan nanoparticles, and gelatin nanoparticles; and / or, the bio-based esters include one or more of bio-based diethyl adipate-propylene glycol ester, bio-based dioctyl adipate, bio-based dibutyl sebacate, bio-based diethyl malonate, bio-based dipropyl succinate, and bio-based tributyl citrate.

[0018] Optionally, the catalyst further includes ammonium 2-hydroxypropyltrimethylformate and a low-temperature active agent, wherein the mass ratio of ammonium 2-hydroxypropyltrimethylformate to the low-temperature active agent is (0.3~2):(0.1~0.3).

[0019] Optionally, the low-temperature active agent includes one or more of N-ethylmorpholine, zinc dithiocarbamate, pentamethyldiethylenetriamine, tetrabutyl titanate, and bio-based ethanolamine.

[0020] Thirdly, embodiments of this application also provide a polyurethane composition comprising isocyanate and the above-described combined polyether.

[0021] Optionally, the polyurethane composition comprises 120 to 135 parts by weight of the isocyanate; and / or, the NCO content of the isocyanate is 31.0% ± 0.5%.

[0022] Fourthly, embodiments of this application also provide a polyurethane foam, which is obtained by foaming the above-mentioned polyurethane composition.

[0023] Optionally, the GWP of the polyurethane foam is <100; and / or, the thermal conductivity of the polyurethane foam at 10°C is ≤17.8 mW / (m²). K); and / or, the core density of the polyurethane foam is 26.0 kg / m³ to 27.5 kg / m³, and the compressive strength of the polyurethane foam is ≥158 kPa; and / or, the dimensional change rate of the polyurethane foam at -30℃ / 24h is ≤0.3%, and the dimensional change rate of the polyurethane foam at 60℃ / 95%RH is ≤0.6%.

[0024] Fifthly, embodiments of this application also provide a refrigeration device, the refrigeration device including a heat insulation layer, the heat insulation layer being made of the aforementioned polyurethane foam.

[0025] The foaming agent composition provided in this application embodiment uses low-GWP bio-based cyclopentane and CO2-based foaming agents, and PFAS-free bio-based siloxane-polyether copolymer as foam stabilizer, so that the foaming agent composition can meet the environmental regulatory requirements of GWP < 100 and no PFAS residue, thus solving the problem that existing foaming agent compositions are difficult to meet environmental regulatory requirements.

[0026] The combined polyether provided in this application embodiment, by combining the foaming agent composition provided in this application embodiment with bio-based polyol, increases the bio-based content of the polyurethane foam prepared using this combined polyether, while meeting the environmental regulatory requirements of GWP < 100 and no PFAS residue, thereby effectively improving the environmental friendliness of polyurethane foam.

[0027] The polyurethane composition provided in this application, by employing the combined polyether provided in this application, increases the bio-based content of the polyurethane foam prepared using this polyurethane composition, while meeting the environmental regulatory requirements of GWP < 100 and no PFAS residue, thereby effectively improving the environmental friendliness of the polyurethane foam. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without creative effort. In the following description, the same reference numerals denote the same parts.

[0029] Figure 1 This is a flowchart illustrating the preparation method of polyurethane foam provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] In the description of this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Additionally, in the description of this application, the term "comprising" means "including but not limited to". The term "exemplary" is used to mean "serving as an example, illustration, or description," and any embodiment described as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other embodiments. The term "and / or" includes any and all combinations of one or more of the associated listed items. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features; thus, features defined with "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0032] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range.

[0033] This application provides a foaming agent composition comprising a foaming agent and a foam stabilizer. The foaming agent comprises bio-based cyclopentane and CO2-based foaming agents, and the foam stabilizer comprises a bio-based siloxane-polyether copolymer.

[0034] The foaming agent composition provided in this application uses low-GWP bio-based cyclopentane and CO2-based foaming agents, and PFAS-free bio-based siloxane-polyether copolymer as a foam stabilizer, so that the foaming agent composition can meet the environmental regulatory requirements of GWP < 100 and no PFAS residue, thus solving the problem that existing foaming agent compositions are difficult to meet environmental regulatory requirements.

[0035] Specifically, bio-based cyclopentane is prepared through plant-based fermentation, and CO2-based blowing agent is converted from industrial by-product CO2. The fluorine-free blowing agent composed of bio-based cyclopentane and CO2-based blowing agent has ODP=0 and GWP<100, thereby improving the environmental friendliness of the blowing agent and solving the problem of non-compliance with environmental standards of traditional HFC-type blowing agents. Moreover, the purity of bio-based cyclopentane is ≥99.5% (few impurities, reducing phase separation interference), and its plant-based origin makes its molecular structure more compatible with the polarity of polyols (weakly polar, containing hydroxyl groups), and the intermolecular forces are coordinated, thereby improving its compatibility with polyols. At the same time, the boiling point of CO2-based blowing agent is usually 5℃~8℃, forming small and uniform pores during foaming, extending the heat transfer path, and its own low thermal conductivity, thus working synergistically with bio-based cyclopentane to optimize the pore structure, reduce heat conduction, and lower the overall thermal conductivity. The bio-based siloxane-polyether copolymer is synthesized from vegetable oils, contains no PFAS, and has a surface tension ≤28mN / m. As a foam stabilizer, it can improve the uniformity of foam nucleation by about 20%, while avoiding the environmental residue problems of traditional PFAS-containing silicone oils. Therefore, the foam composition provided in this application can improve the environmental friendliness of polyurethane foam while taking into account its thermal insulation performance and strength.

[0036] In some embodiments of this application, the foaming agent composition comprises 12 to 25 parts by weight of the foaming agent and 1 to 4 parts by weight of the foam stabilizer. By controlling the proportions of each component in the foaming agent composition within the above range, the polyurethane foam prepared using the foaming agent composition of this application can possess both environmental friendliness and good mechanical properties.

[0037] For example, the mass fraction of the foaming agent can be 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any range between any two of the aforementioned values; the mass fraction of the foam stabilizer can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, or any range between any two of the aforementioned values.

[0038] Optionally, the mass ratio of the bio-based cyclopentane to the CO2-based blowing agent is (8~12):(3~5), for example, it can be 8:3, 8:5, 10:4, 12:3, 12:5, or any range between the two aforementioned ratios. By controlling the proportion of bio-based cyclopentane to CO2-based blowing agent within the above range, the polyurethane foam prepared using the blowing agent composition of this application can achieve both thermal insulation and dimensional stability.

[0039] Optionally, the CO2-based blowing agent may be a dimethyl carbonate derivative, which includes one or more of diethyl carbonate, methyl ethyl carbonate, methyl ethylene carbonate, dipropyl carbonate, and dimethyl carbonate-propylene oxide copolymer.

[0040] In some embodiments of this application, the bio-based siloxane-polyether copolymer is prepared by the following method: alcoholysis of vegetable oil to obtain a bio-based polyol; and copolymerization reaction of the bio-based polyol, polyether monomer, siloxane monomer and a first catalyst to obtain the bio-based siloxane-polyether copolymer.

[0041] Specifically, the surface tension of the bio-based siloxane-polyether copolymer is ≤28 mN / m. The preparation method of the bio-based siloxane-polyether copolymer may include the following steps: mixing vegetable oil with alcohols (e.g., glycerol, propylene glycol, or butanediol), and then alcoholystothening at 180℃~220℃ for 2h~4h under the catalysis of an alkaline catalyst to obtain a bio-based polyol; mixing the bio-based polyol, polyether monomer, and siloxane monomer, adding a first catalyst, reacting at 80℃~120℃ for 3h~5h, adjusting the pH to 6~7, removing low-boiling substances under reduced pressure, and then filtering to obtain a bio-based siloxane-polyether copolymer with a surface tension ≤28 mN / m. The mass ratio of vegetable oil to alcohol is 1:(0.2~0.3), and the alkaline catalyst accounts for 0.5%~1.0% of the total mass of vegetable oil, alcohol, and alkaline catalyst.

[0042] Optionally, the mass ratio of the bio-based polyol, the polyether monomer, and the siloxane monomer is (50~70):(20~30):(5~15), and the first catalyst accounts for 0.01%~0.1% of the total mass of the bio-based polyol, the polyether monomer, the siloxane monomer, and the first catalyst. By controlling the proportions of the bio-based polyol, the polyether monomer, the siloxane monomer, and the first catalyst within the above-mentioned range, the prepared bio-based siloxane-polyether copolymer can more effectively stabilize the cell structure, prevent cell collapse or merging during foaming, and thus enable the polyurethane foam to have good mechanical properties.

[0043] For example, the mass ratio of the bio-based polyol, the polyether monomer, and the siloxane monomer can be 50:20:5, 50:20:15, 50:30:5, 50:30:15, 70:20:5, 70:20:15, 70:30:5, 70:30:15, 60:25:10, or any two of the aforementioned ratios; the first catalyst can account for 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1% of the total mass of the bio-based polyol, the polyether monomer, the siloxane monomer, and the first catalyst, or any two of the aforementioned values.

[0044] Optionally, the vegetable oil includes one or more of rapeseed oil, soybean oil, palm oil, flaxseed oil, cottonseed oil, and sunflower oil. Optionally, the polyether monomer includes one or more of propylene oxide / ethane polymers, tetrahydrofuran homopolymers, butane oxide polymers, epichlorohydrin-ethylene oxide copolymers, and glycidyl ether polyethers. Optionally, the siloxane monomer includes one or more of octamethylcyclotetrasiloxane (D4), tetramethyltetravinylcyclotetrasiloxane (D4Vi), methyltrimethoxysilane, and vinyltriethoxysilane. Optionally, the first catalyst includes a first base catalyst or a platinum catalyst; wherein the first base catalyst includes one or more of potassium hydroxide (KOH) and sodium hydroxide (NaOH), and the platinum catalyst includes one or more of chloroplatinic acid, platinum-vinylsiloxane complexes (Karstedt catalysts), platinum-cyclopentadiene complexes, and platinum-phosphine ligand complexes.

[0045] This application also provides a composite polyether comprising a polyol composition and the aforementioned foaming agent, wherein the polyol composition comprises a bio-based polyol.

[0046] The combined polyether provided in this application embodiment uses a bio-based polyol in combination with the foam composition of this application. The bio-based polyol is a type of bio-based polyol that can reduce the carbon footprint, thereby increasing the bio-based content of the polyurethane foam prepared using this combined polyether, thus improving the environmental friendliness of the polyurethane foam.

[0047] Optionally, the combined polyether comprises 100 parts of the polyol composition by weight, such that the mass ratio of the polyol composition, blowing agent, and foam stabilizer is 100:(12~25):(1~4). By controlling the proportions of each component of the combined polyether within the above range, the polyurethane foam prepared using the combined polyether of this application can possess environmental friendliness, good flowability, and good mechanical properties. For example, the mass ratio of the polyol composition, blowing agent, and foam stabilizer can be 100:12:1, 100:12:4, 100:25:1, 100:25:4, 100:18:3, or any range between the aforementioned two ratios.

[0048] In some embodiments of this application, the bio-based polyol comprises a modified starch-castor oil composite polyol and an epoxy compound grafted onto the modified starch-castor oil composite polyol, with a grafting rate of 30% to 40%. That is, the bio-based polyol is obtained by a composite grafting reaction of modified starch, castor oil, and an epoxy compound. This application uses a modified starch-castor oil composite polyol grafted with an epoxy compound. The epoxy compound contains a multi-ring structure (high ring strain, easy ring opening), which reacts with the active groups in the modified starch-castor oil composite polyol during grafting and introduces new hydroxyl groups. This increases the number of reaction sites and improves the hydroxyl value, enhancing the reactivity of the hydroxyl groups with the NCO groups of isocyanate. A large number of hydroxyl groups fully react with the NCO groups of isocyanate, forming more cross-linking bonds and increasing the cross-linking density, thereby improving the compressive strength of the polyurethane foam. Simultaneously, the modified starch-castor oil composite polyol reduces the carbon footprint and improves environmental friendliness, solving the problem of the traditional technology's trade-off between strength and environmental protection.

[0049] Optionally, the preparation method of the bio-based polyol includes the following steps: (1) Pretreatment: starch is modified by esterification (such as acetic anhydride esterification) or etherification to obtain modified starch. The modified starch is dried at 100℃~110℃ for 2h-3h to remove water. Castor oil is dehydrated by vacuum distillation at 110℃~120℃; (2) Composite grafting: the dehydrated castor oil and modified starch are mixed in proportion, a second base catalyst is added, the temperature is raised to 100℃~120℃, an epoxy compound is introduced, and the reaction is carried out at 0.3MPa~0.5MPa for 4h~6h; (3) Posttreatment: after neutralization, the low-boiling substances are removed by vacuum (0.005MPa~0.02MPa), and the mixture is filtered to obtain the bio-based polyol. The ratio of starch to esters or ethers, and the ratio of modified starch, castor oil and epoxy compounds can be adjusted according to the target hydroxyl value of the bio-based polyol.

[0050] Specifically, the esterification or etherification modification of starch includes: mixing starch with esters (e.g., acetic anhydride) or ethers, and reacting at 60℃~90℃ for 2h~4h to obtain modified starch; wherein the ratio of starch to esters or ethers can be adjusted according to the target hydroxyl value. The neutralization operation includes: adding organic acids such as acetic acid to the reaction solution to adjust the pH to 6~7, and stirring for 10min~30min. The pressure range for removing low-boiling substances under reduced pressure is 0.005MPa~0.02MPa.

[0051] Optionally, the epoxy compound may include one or more of propylene oxide, cyclohexane oxide, ethylene oxide, butane oxide, and phenyl glycidyl ether. Optionally, the second base catalyst may include one or more of potassium hydroxide (KOH) and sodium hydroxide (NaOH).

[0052] Optionally, the bio-based polyol has a bio-based content of ≥70%, a hydroxyl value of 280mgKOH / g~320mgKOH / g, and a viscosity of 1500mPa at 25°C. s~2000mPa This configuration allows the polyurethane foam prepared using the combined polyethers of this application to possess environmental friendliness, good flowability, and good mechanical properties. For example, the bio-based content of the bio-based polyol can be 70%, 75%, 80%, 85%, 90%, 95%, 98%, or any range between two of the aforementioned values; the hydroxyl value of the bio-based polyol can be 280 mg KOH / g, 290 mg KOH / g, 300 mg KOH / g, 310 mg KOH / g, 320 mg KOH / g, or any range between two of the aforementioned values; and the viscosity of the bio-based polyol at 25°C can be 1500 mPa. s, 1600mPa s, 1700mPa s, 1800mPa s, 1900mPa s, 2000mPa The range between any two values ​​mentioned above, etc.

[0053] In some embodiments of this application, step (2), the addition of the second alkaline catalyst, includes adding a second alkaline catalyst and a nucleating agent. The nucleating agent includes one or more of polycaprolactone (PCL), polyethylene glycol (PEG), polylactide (PLA), butylene adipate (PBA), polytrimethylene carbonate (PTMC), and polycaprolactone-polyethylene glycol block copolymer (hereinafter referred to as PCL-PEG block copolymer). By adding the above-mentioned nucleating agent, the crystallinity of the modified starch-castor oil composite polyol can be controlled, thereby improving the dimensional stability of polyurethane foam. This ensures that the dimensional change rate of polyurethane foam under -30℃ / 24h conditions is ≤0.3%, and the dimensional change rate under 60℃ / 95%RH conditions is ≤0.6%, thus solving the problem of excessive shrinkage deformation of the box after low-temperature demolding of polyurethane foam.

[0054] Optionally, the mass fraction of the nucleating agent is 0.5 to 1 part. For example, the mass fraction of the nucleating agent can be 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, 1 part, or any range between two of the aforementioned values.

[0055] In some embodiments of this application, the polyol composition comprises, by weight parts, 20-30 parts of bio-based polyol, 10-20 parts of sorbitol polyether, 18-25 parts of o-tolyl diamine polyether, 10-22 parts of sucrose-propylene glycol composite polyether, and 20-25 parts of glycerol polyether. Sorbitol polyether, with its high functionality, can improve the crosslinking density, mechanical strength, and heat resistance of polyurethane foam; o-tolyl diamine polyether can enhance the compressive strength and heat stability of polyurethane foam; sucrose-propylene glycol composite polyether can balance the rigidity and toughness of polyurethane foam and optimize its moldability; and glycerol polyether, as a base polyether, participates in crosslinking, which can improve the dimensional stability and system compatibility of polyurethane foam.

[0056] For example, the mass fraction of the bio-based polyol can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, or any range between any two of the aforementioned values; the mass fraction of the sorbitol polyether can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, or any range between any two of the aforementioned values; the mass fraction of the o-toluene diamine polyether can be 18 parts, 19 parts, ... The mass fractions of the sucrose-propylene glycol composite polyether can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or any two of the aforementioned values; the mass fractions of the glycerol polyether can be 20, 21, 22, 23, 24, 25, or any two of the aforementioned values.

[0057] Optionally, the sorbitol polyether has a hydroxyl value of 400 mg KOH / g to 450 mg KOH / g and a viscosity of 7500 mPa at 25°C. s~9500mPa The sorbitol polyether has a functionality of 5-7. For example, the hydroxyl value of the sorbitol polyether can be 400 mg KOH / g, 410 mg KOH / g, 420 mg KOH / g, 430 mg KOH / g, 440 mg KOH / g, 450 mg KOH / g, or any range between two of the aforementioned values; the viscosity of the sorbitol polyether at 25°C can be 7500 mPa. s, 8000mPa s, 8500mPa s, 9000mPa s, 9500mPa The functionality of sorbitol polyether can be 5, 6, 7, or any range between two of the aforementioned values.

[0058] Optionally, the o-toluene diamine polyether has a hydroxyl value of 380 mg KOH / g to 420 mg KOH / g and a viscosity of 7000 mPa at 25°C. The viscosity ranges from s to 8000 mPa·s, with a functionality of 3 to 5. For example, the hydroxyl value of o-toluene diamine polyether can be 380 mg KOH / g, 390 mg KOH / g, 400 mg KOH / g, 410 mg KOH / g, 420 mg KOH / g, or any range between two of the aforementioned values; the viscosity of o-toluene diamine polyether at 25°C can be 7000 mPa·s. s, 7100mPa s, 7200mPa s, 7300mPa s, 7400mPa s, 7500mPa s, 7600mPa s, 7700mPa s, 7800mPa s, 7900mPa The functionality of o-toluene diamine polyether can be 3, 4, 5, or any two of the aforementioned values.

[0059] Optionally, the sucrose-propylene glycol composite polyether has a hydroxyl value of 350 mg KOH / g to 450 mg KOH / g and a viscosity of 6000 mPa at 25°C. s~8000mPa The sucrose-propylene glycol composite polyether has a functionality of 6-8. For example, the hydroxyl value of the sucrose-propylene glycol composite polyether can be 350 mg KOH / g, 360 mg KOH / g, 370 mg KOH / g, 380 mg KOH / g, 390 mg KOH / g, 400 mg KOH / g, 410 mg KOH / g, 420 mg KOH / g, 430 mg KOH / g, 440 mg KOH / g, 450 mg KOH / g, or any range between two of the aforementioned values; the viscosity of the sucrose-propylene glycol composite polyether at 25°C can be 6000 mPa. s, 6500mPa s, 7000mPa s, 7500mPa s, 8000mPa The functionality of the sucrose-propylene glycol composite polyether can be 6, 7, 8, or any range between two of the aforementioned values.

[0060] Specifically, the sucrose-propylene glycol composite polyether can be prepared by the following method: sucrose and propylene glycol are mixed in a certain proportion, a third base catalyst is added, and propylene oxide is introduced. The mass ratio of sucrose, propylene glycol, the third base catalyst, and propylene oxide is 1:(0.3~0.6):(0.01~0.03):(2.5~4.0). Then, the reaction is carried out at 80℃~100℃ and 0.3MPa~0.5MPa for 4h~6h. After neutralization, low-boiling substances are removed under reduced pressure to obtain the sucrose-propylene glycol composite polyether.

[0061] Optionally, the hydroxyl value of the glycerol polyether is 230 mg KOH / g to 270 mg KOH / g, and the functionality is 2 to 3. For example, the hydroxyl value of the glycerol polyether can be 230 mg KOH / g, 240 mg KOH / g, 250 mg KOH / g, 260 mg KOH / g, 270 mg KOH / g, or any range between two of the aforementioned values; the functionality of the glycerol polyether can be 2, 2.5, 3, or any range between two of the aforementioned values.

[0062] In some embodiments of this application, the combined polyether further comprises 0.5 to 3.5 parts of water by weight. The water, as a chemical blowing agent, reacts with the NCO of the isocyanate to generate CO2, helping to adjust the cell density and balance the thermal conductivity and strength of the polyurethane foam. Exemplarily, the weight percentage of water can be 0.5, 0.7, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.7, 3.0, 3.3, 3.5, or any range between the aforementioned values.

[0063] In some embodiments of this application, the combined polyether further comprises, by weight parts, 1 to 3.5 parts of catalyst and 1 to 3 parts of viscosity modifier. The catalyst comprises pentamethyldiethylenetriamine, a bio-based amine auxiliary agent, dimethylcyclohexylamine, and a temperature-responsive nanocarrier. The viscosity modifier comprises a bio-based ester. Exemplarily, the weight parts of the catalyst can be 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.7 parts, 3.0 parts, 3.3 parts, 3.5 parts, or any range between any two of the aforementioned values; the weight parts of the viscosity modifier can be 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.7 parts, 3.0 parts, or any range between any two of the aforementioned values.

[0064] The new energy efficiency standard requires that the thermal conductivity of refrigerator insulation materials be ≤18.0 mW / (m²). For ultra-thin refrigerators (polyurethane foam thickness ≤ 50 mm), the foaming liquid flow index should be ≥ 0.85 cm / g to avoid voids. However, the existing polyurethane foam has a foaming liquid flow index < 0.85 cm / g and insufficient strength at low density (≤ 27 kg / m³) (compressive strength < 150 kPa), failing to simultaneously meet the requirements of new energy efficiency and ultra-thin design. This application utilizes catalysts such as pentamethyldiethylenetriamine, bio-based amine additives, dimethylcyclohexylamine, and temperature-responsive nanocarriers in combination with bio-based ester viscosity modifiers. The bio-based ester viscosity modifiers can reduce the viscosity of the material to 280 mPa in the early stages of foaming. s~320mPa At 20℃, the flow index is ensured to be ≥0.88cm / g, solving the void problem caused by insufficient flowability of the foaming liquid in the ultra-thin mold. Furthermore, the viscosity modifier automatically cross-links with increasing temperature in the later stages of foaming, without affecting the strength of the polyurethane foam. The catalyst also extends the milky whitening time and shortens the gel time, thus enabling the polyurethane foam preparation process to balance high flowability and rapid curing, with ultra-thin box deformation <1.05mm. In other words, this application, through the synergistic regulation of bio-based ester viscosity modifiers and catalysts, can ensure high flowability of the foaming liquid and eliminate voids and reduce deformation within the ultra-thin mold (thickness ≤50mm), thereby simultaneously meeting the requirements of new energy efficiency and ultra-thin design, solving the problem of adapting new energy efficiency to ultra-thin design.

[0065] Optionally, the mass ratio of the pentamethyldiethylenetriamine, the bio-based amine additive, the dimethylcyclohexylamine, and the temperature-responsive nanocarrier is (0.1~6):(0.1~0.3):(0.5~7):(0.01~0.5). By setting the mass ratio of pentamethyldiethylenetriamine, the bio-based amine additive, the dimethylcyclohexylamine, and the temperature-responsive nanocarrier within the above range, the milky whitening time can be extended to 10s~12s (the flow window is expanded by about 30%, ensuring sufficient flow of the foaming liquid), and the gelation time can be shortened to 38s~40s, thereby improving the curing efficiency by about 15%, thus achieving a balance between high flowability and rapid curing.

[0066] For example, the mass ratio of the pentamethyldiethylenetriamine, the bio-based amine adjuvant, the dimethylcyclohexylamine, and the temperature-responsive nanocarrier can be 0.1:0.1:0.5:0.01, 0.1:0.3:0.5:0.01, 0.1:0.3:7:0.01, 0.1:0.3:7:0.5, 6:0.1:0.5:0.01, 6:0.3:0.5:0.01, 6:0.3:7:0.01, 6:0.3:7:0.5, 3:0.2:3.8:0.3, or any range between the aforementioned two ratios.

[0067] Optionally, the bio-based amine adjuvant includes one or more of bio-based ethanolamine, chitosan-based amine adjuvants, soybean protein-based amine, bio-based propylamine, and bio-based butylamine. Optionally, the temperature-responsive nanocarrier includes one or more of nano-silica, nano-titanium dioxide, poly(N-isopropylacrylamide) (PNIPAM)-based nanocarriers, chitosan nanoparticles, and gelatin nanoparticles.

[0068] Optionally, the bio-based esters include one or more of the following: bio-based diethyl adipate-propylene glycol ester, bio-based dioctyl adipate (DOA), bio-based dibutyl sebacate (DBS), bio-based diethyl malonate, bio-based dipropyl succinate, and bio-based tributyl citrate (TBC).

[0069] In some embodiments of this application, the catalyst further includes ammonium 2-hydroxypropyltrimethylformate and a low-temperature activating agent, wherein the mass ratio of ammonium 2-hydroxypropyltrimethylformate to the low-temperature activating agent is (0.3~2):(0.1~0.3). Exemplarily, the mass ratio of ammonium 2-hydroxypropyltrimethylformate to the low-temperature activating agent can be 0.3:0.1, 0.3:0.3, 2:0.1, 2:0.3, 1.2:0.2, or any range between the aforementioned two ratios.

[0070] Existing polyurethane foams rely on high-temperature molds (around 40°C) for rapid demolding (demolding time <160s). During winter production, when the mold temperature drops to 15°C~25°C, the demolding time extends to over 200s, and the polyurethane foam expansion rate exceeds 3.0%, leading to excessive deformation of the foam casing. This indicates that existing polyurethane foams suffer from low-temperature production efficiency and poor stability. This application addresses this issue by using 2-hydroxypropyltrimethylformate in combination with a low-temperature active additive. When the mold temperature is 15°C~25°C (winter production), the low-temperature active additive enhances catalyst activity, resulting in a demolding time <140s, achieving efficient demolding under low-temperature mold conditions. Furthermore, when the mold temperature is 30°C~40°C, the low-temperature active additive automatically deactivates, preventing polyurethane foam embrittlement caused by over-catalysis. This solves the problems of slow low-temperature demolding and easy embrittlement at high temperatures inherent in traditional technologies.

[0071] Optionally, the low-temperature active additive includes one or more of N-ethylmorpholine, zinc dithiocarbamate (ZDMC), pentamethyldiethylenetriamine (PC-5), tetrabutyl titanate, and bio-based ethanolamine. By selecting these low-temperature active additives, they can form hydrogen bonds with 2-hydroxypropyltrimethylammonium carboxylate, increasing catalyst activity by 40% to 50% at 15℃ to 25℃, ensuring that the demolding time of polyurethane foam is <140s, while maintaining the compressive strength of polyurethane foam ≥158kPa, which is different from the traditional technology's approach of "low-temperature demolding requires sacrificing strength." When the mold temperature is 30℃ to 40℃, these low-temperature active additives will automatically deactivate, avoiding polyurethane foam embrittlement caused by over-catalysis.

[0072] This application also provides a polyurethane composition comprising isocyanate and a combined polyether, wherein the specific structure of the polyurethane foam is as described in the above embodiments. Since the polyurethane composition employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0073] Optionally, the polyurethane composition comprises 120 to 135 parts by weight of the isocyanate; and / or, the NCO content of the isocyanate is 31.0% ± 0.5%. Exemplarily, the weight of the isocyanate can be 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135 parts, or any range between any two of the aforementioned values; the NCO content of the isocyanate can be 30.5%, 30.6%, 30.7%, 30.8%, 30.9%, 31.0%, 31.1%, 31.2%, 31.3%, 31.4%, 31.5%, or any range between any two of the aforementioned values.

[0074] Optionally, the isocyanate includes one or more of polymethylene polyphenyl isocyanate (PAPI), phenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), and toluene diisocyanate (TDI).

[0075] In some embodiments of this application, the polyurethane composition, by weight, comprises 100 parts of the polyol composition, 12 to 25 parts of the blowing agent, 1.0 to 4.0 parts of the foam stabilizer, 1.0 to 3.5 parts of the catalyst, 0.5 to 3.5 parts of water, 120 to 135 parts of the isocyanate, and 1 to 3 parts of the viscosity modifier. By controlling the proportions of each component in the polyurethane composition within the above range, the polyurethane foam prepared using the polyurethane composition of this application can possess environmental friendliness, good flowability, and good mechanical properties.

[0076] This application also provides a polyurethane foam, which is obtained by foaming the above-described polyurethane composition. Since the polyurethane foam adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0077] Optionally, the GWP of the polyurethane foam is <100. Optionally, the thermal conductivity of the polyurethane foam at 10°C is ≤17.8 mW / (m²). K). Optionally, the core density of the polyurethane foam is 26.0 kg / m³ to 27.5 kg / m³, and the compressive strength of the polyurethane foam is ≥158 kPa. Optionally, the dimensional change rate of the polyurethane foam at -30℃ / 24h is ≤0.3%, and the dimensional change rate of the polyurethane foam at 60℃ / 95%RH is ≤0.6%.

[0078] In some embodiments of this application, as shown in the figures, the method for preparing the polyurethane foam described above may include the following steps: S100: A preliminary mixture is obtained by mixing a polyol composition, a catalyst, water, a foam stabilizer, and a viscosity modifier. S200: After mixing bio-based cyclopentane with the initial mixture, CO2-based foaming agent is added and mixed to obtain the premix; S300: The premix is ​​mixed with isocyanate and foamed to obtain polyurethane foam.

[0079] Optionally, step S100 includes: stirring the polyol composition, catalyst, water, foam stabilizer, and viscosity modifier at 25℃±5℃ and 0.8MPa~1.2MPa for 0.8h~1.2h, with a stirring speed of 500r / min~800r / min, to obtain a preliminary mixture. By setting the stirring speed to 500r / min~800r / min, it is ensured that each component is uniformly dispersed (dispersion ≤5μm).

[0080] Optionally, step S200 includes: mixing bio-based cyclopentane with a premix at 20℃~25℃ and 1.0MPa~1.5MPa for 0.5h~1.0h, then adding a CO2-based foaming agent and mixing at 20℃~25℃ and 2.5MPa~3.0MPa for 0.3h~0.5h to obtain a premix. By controlling the mixing temperature at 20℃~25℃, the volatilization of bio-based cyclopentane due to temperature fluctuations is avoided (i.e., the volatilization rate of bio-based cyclopentane is controlled to be ≤0.5%).

[0081] Optionally, step S300 includes: injecting the premix and isocyanate into an ultra-thin mold (thickness ≤ 50 mm) with a filler factor of 1.05 to 1.20 (the ratio of the volume of the premix to the effective volume of the ultra-thin mold cavity), curing at 15°C to 40°C for 120 to 140 seconds, and then demolding to obtain polyurethane foam.

[0082] This application also provides a refrigeration device, which includes an insulation layer made of polyurethane foam. The specific structure of the polyurethane foam is described in the above embodiments. Since this refrigeration device employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0083] Optionally, the refrigeration equipment can be a refrigerator, freezer, biological sample transport box, or cold chain container, etc. Optionally, the thickness of the insulation layer is 30mm to 50mm, for example, it can be 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, or any range between two of the aforementioned values.

[0084] The technical solutions and effects of this application will be described in detail below through specific embodiments and comparative examples. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0085] Raw material preparation: Bio-based polyol: In-house prepared using the following method: starch and acetic anhydride are mixed and reacted at 60℃~90℃ for 2-4 hours to obtain modified starch; the modified starch is dried at 110℃ for 2 hours to remove water; castor oil is dehydrated by vacuum distillation at 110℃; the dehydrated castor oil and modified starch are mixed, KOH catalyst is added, the temperature is raised to 110℃, propylene oxide is introduced, and the reaction is carried out at 0.4MPa for 5 hours; after neutralization, low-boiling substances are removed by vacuum distillation (0.01MPa), and the product is filtered to obtain the bio-based polyol. The hydroxyl value of this bio-based polyol is 300mgKOH / g, and the viscosity at 25℃ is 1800mPa. s, with a bio-based content of 75%.

[0086] Sorbitol polyether: hydroxyl value 420 mg KOH / g, viscosity 8500 mPa at 25℃ s, with a functionality of 6, was purchased from Nanjing Ningwu Chemical Company.

[0087] o-Toluene diamine polyether: hydroxyl value 400 mg KOH / g, viscosity 7500 mPa at 25℃ s, with a functionality of 4, was purchased from Nanjing Hongbaoli Company.

[0088] Sucrose-propylene glycol composite polyether: Prepared in-house, the specific preparation method is as follows: sucrose and propylene glycol are mixed in a certain proportion, KOH catalyst is added, and propylene oxide is introduced. The mass ratio of sucrose, propylene glycol, KOH catalyst, and propylene oxide is 1:0.45:0.02:3. The mixture is then reacted at 90℃ and 0.4MPa for 5 hours. After neutralization, low-boiling substances are removed under reduced pressure to obtain the sucrose-propylene glycol composite polyether. The hydroxyl value of this sucrose-propylene glycol composite polyether is 400 mgKOH / g, and the viscosity at 25℃ is 7000 mPa. s, with a functionality of 7.

[0089] Glyceryl polyether: hydroxyl value of 250 mg KOH / g, functionality of 3, purchased from Wanhua Chemical Company.

[0090] Bio-based cyclopentane: purity 99.5%, bio-based content ≥90%, purchased from Shandong Luhua Biotechnology Co., Ltd.

[0091] CO2-based foaming agent: dimethyl carbonate derivative, boiling point 7℃, purchased from Zhejiang Juhua Company.

[0092] Foam stabilizer: Bio-based siloxane-polyether copolymer with a surface tension of 27 mN / m, customized by Momentive Advanced Materials Co., Ltd. The preparation method is as follows: Rapeseed oil and glycerin are mixed at a mass ratio of 1:0.25, and then alcoholyzed at 200℃ for 3 hours under the catalysis of a KOH catalyst (the KOH catalyst accounts for 0.8% of the total mass of the KOH catalyst, rapeseed oil, and glycerin) to obtain a bio-based polyol. The bio-based polyol, propylene oxide / ethane polymer, and octamethylcyclotetrasiloxane are mixed at a mass ratio of 60:25:10, and then a KOH catalyst is added (the KOH catalyst accounts for 0.05% of the total mass of the KOH catalyst, bio-based polyol, propylene oxide / ethane polymer, and octamethylcyclotetrasiloxane). After reacting at 100℃ for 4 hours, the pH is adjusted to 7, and then low-boiling substances are removed under reduced pressure. The mixture is then filtered to obtain the bio-based siloxane-polyether copolymer.

[0093] Viscosity modifier: Diethyl adipate-propylene glycol ester, viscosity at 25°C is 250 mPa. s, purchased from Jiangsu Zhongshan Chemical Company.

[0094] Catalyst: In-house prepared, prepared by mixing pentamethyldiethylenetriamine, bio-based ethanolamine, dimethylcyclohexylamine, nano-silica, 2-hydroxypropyltrimethylformate ammonium, and N-ethylmorpholine in a mass ratio of 3:0.2:3.8:0.3:1.2:0.2. Pentamethyldiethylenetriamine, bio-based ethanolamine, dimethylcyclohexylamine, nano-silica, 2-hydroxypropyltrimethylformate ammonium, and N-ethylmorpholine were all purchased from Aladdin Reagent Company.

[0095] Isocyanate: PM-200 (polymethylene polyphenyl isocyanate), NCO content 31.0%, viscosity at 25°C 700 mPa s, purchased from Yantai Wanhua Company.

[0096] Example 1 (1) Mix bio-based polyol, sorbitol polyether, o-toluene diamine polyether, sucrose-propylene glycol composite polyether, glycerol polyether, catalyst, water, foam stabilizer and viscosity modifier, and stir at 25℃ and 1.0MPa for 1.0h with a stirring speed of 650r / min to obtain the initial mixture; S200: Bio-based cyclopentane is mixed with the initial mixture at 20℃ and 1.2MPa for 1.0h, and then a CO2-based foaming agent is added and mixed at 20℃ and 3.0MPa for 0.4h to obtain the premix. S300: The premix and isocyanate are injected into an ultra-thin mold (mold cavity thickness 40mm) with a filler factor of 1.10, cured at 30℃ for 130s, and then demolded to obtain polyurethane foam.

[0097] Example 2 Example 2 is basically the same as Example 1, except that the amount of each component except glycerol polyether is different in Example 2.

[0098] Example 3 Example 3 is basically the same as Example 1, except that the amount of all components added in Example 3 is different from that in Example 1.

[0099] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, with the main differences being: in Comparative Example 1, lignin-based polyol is used to replace the bio-based polyol in Example 1, cycloisopentane and HFC-245fa (i.e., 1,1,1,3,3-pentafluoropropane) are used to replace the bio-based cyclopentane and CO2-based foaming agent in Example 1, respectively, silicone oil (containing PFAS) of type B84806 is used to replace the foam stabilizer in Example 1, PC-5 (i.e., pentamethyldiethylenetriamine) is used to replace the catalyst in Example 1, and no viscosity modifier is added to Comparative Example 1.

[0100] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, with the main differences being: sorbitol is used to replace the bio-based polyol in Example 1 in Comparative Example 2; cyclopentane and HFC-134a (i.e., 1,1,1,2-tetrafluoroethane) are used to replace the bio-based cyclopentane and CO2-based foaming agent in Example 1, respectively; silicone oil (containing PFAS) of type B84806 is used to replace the foam stabilizer in Example 1; PC-5 (i.e., pentamethyldiethylenetriamine) is used to replace the catalyst in Example 1; and no viscosity modifier is added in Comparative Example 2.

[0101] Comparative Example 3 Comparative Example 3 is basically the same as Example 1, with the main differences being: sucrose polyether is used to replace the bio-based polyol in Example 1, cyclopentane and HFC-245fa (i.e., 1,1,1,3,3-pentafluoropropane) are used to replace the bio-based cyclopentane and CO2-based blowing agent in Example 1, respectively, silicone oil (containing PFAS) of type B84806 is used to replace the foam stabilizer in Example 1, PC-5 (i.e., pentamethyldiethylenetriamine) is used to replace the catalyst in Example 1, and no viscosity modifier is added to Comparative Example 3.

[0102] Specifically, the amount (parts by mass) of each component added in Examples 1-3 and Comparative Examples 1-3 is shown in Table 1 below.

[0103] Table 1

[0104] Performance tests were conducted on the polyurethane foams of Examples 1-3 and Comparative Examples 1-3, and the test results are detailed in Table 2 below. The performance test items included: viscosity, flow index, demolding time, core density, thermal conductivity at 20°C, compressive strength, expansion rate, dimensional stability, HFC content, PFAS residue, and box deformation (ultra-thin parts).

[0105] The testing methods for each performance aspect are as follows: Viscosity: The viscosity of the premix at 20℃ was tested according to GB / T 12008.8-2010; Flow index: The flow distance and mass of the foaming liquid injected into the ultra-thin mold (1200×400×40mm) are measured, and the ratio of the flow distance to the mass of the foaming liquid is calculated to obtain the flow index (cm / g). Demolding time: Record the time from when foam is injected into a 20℃ mold to when it can be successfully demolded, and the time from when foam is injected into a 40℃ mold to when it can be successfully demolded; Core density: The core density of polyurethane foam was tested using the water displacement method according to GB / T6343-2009. Thermal conductivity: The thermal conductivity of polyurethane foam at 10℃ was tested according to GB / T10295-2008. Compressive strength: According to GB / T10295-2008, the compressive strength of polyurethane foam at 25% deformation was tested; Expansion rate: According to ASTM C1643, the percentage of volume expansion of polyurethane foam within 3 minutes after demolding is tested.

[0106] Dimensional stability: According to GB / T 8811-2008, the dimensional change rate of polyurethane foam under the condition of -30℃×24h and the dimensional change rate under the condition of 60℃ / 95%RH were tested.

[0107] HFC content: The content of HFC substances in polyurethane foam was tested by gas chromatography-mass spectrometry in accordance with HJ 1057-2019.

[0108] PFAS residue: The PFAS residue in polyurethane foam was tested by ion chromatography in accordance with GB / T 5750.10-2023. Deformation of the cabinet (ultra-thin parts): According to GB / T 6342 (Method for determination of linear dimensions of foamed plastics), the deformation value of the ultra-thin parts of the ultra-thin refrigerator cabinet is measured with a micrometer.

[0109] Table 2

[0110] As shown in Table 2, the polyurethane foams of Examples 1-3 are free of HFC and PFAS residues, fully complying with environmental regulations (HFC blowing agent usage reduced to less than 15% of the baseline, and PFAS-free); while the polyurethane foams of Comparative Examples 1-3 contain both HFC and PFAS, failing to meet environmental regulations.

[0111] The polyurethane foams in Examples 1-3 have a flow index ≥ 0.90 cm / g, and the premix has a viscosity ≤ 315 mPa at 25°C. The ultra-thin box deformation was ≤1.02mm, with no voids, indicating that the polyurethane foam of Examples 1-3 has good ultra-thin adaptability; while the polyurethane foam of Comparative Examples 1-3 had a flow index <0.85cm / g, ultra-thin box deformation >1.27mm, and some voids appeared.

[0112] The polyurethane foams of Examples 1-3 exhibited a demolding time of <140s in a mold at 20℃, achieving rapid demolding at low temperature (rapid demolding time <160s). Furthermore, the polyurethane foams of Examples 1-3 had a thermal conductivity ≤17.8mW / (m²) at 10℃. K), meeting the new energy efficiency standard (thermal conductivity ≤ 18.0 mW / (m²)). K); while the polyurethane foams of Comparative Examples 1-3 had a demolding time of >170s in the mold at 20℃, failing to achieve rapid demolding at low temperature, and the polyurethane foams of Comparative Examples 1-3 had a thermal conductivity of >18.3mW / (m²) at 10℃. K), energy efficiency does not meet standards.

[0113] The demolding time of the polyurethane foams in Examples 1-3 at 40°C (115s-125s) was shorter than that of the polyurethane foams in Comparative Examples 1-3 at 40°C (150s-165s), indicating that the polyurethane foams in Examples 1-3 are more conducive to improving production efficiency.

[0114] The polyurethane foams in Examples 1-3 have a core density of ≤27.5kg / m³ and a compressive strength of ≥158KPa, achieving a balance between "low density and high strength". Moreover, the polyurethane foams in Examples 1-3 use bio-based blowing agents instead of expensive HFC blowing agents, thus reducing raw material costs.

[0115] In summary, this application has, but is not limited to, the following advantages: (i) Achieving bio-based fluorine-free and PFAS-free 1. This application uses bio-based polyols (bio-based content ≥70%) to replace part of the sucrose polyether / sorbitol polyether. The modified starch-castor oil composite polyol is modified by propylene oxide grafting (grafting rate 30%~40%) to improve its reactivity. Unlike the existing lignin-based polyols (which require high temperature and high pressure modification, resulting in a 30% higher modification cost), the modification process used in this application is mild and can reduce raw material costs by 8%~12%. The bio-based polyol has a hydroxyl value of 280mgKOH / g~320mgKOH / g and a viscosity of 1500mPa at 25℃. s~2000mPa This can both improve the strength of polyurethane foam and reduce its carbon footprint.

[0116] 2. Fluorine-free foaming agent combination: This application uses bio-based cyclopentane (prepared by plant-based fermentation) and CO2-based foaming agent (conversion of industrial by-product CO2) to replace HFC-type foaming agents. The compatibility of bio-based cyclopentane with polyols is improved by about 15%. The boiling point of CO2-based foaming agent (such as dimethyl carbonate derivative) is 5℃~8℃, which synergistically reduces the thermal conductivity. Moreover, the foaming agent has ODP=0 and GWP<100, which meets the requirements of environmental protection regulations.

[0117] 3. PFAS-free foam stabilizer: This application uses a bio-based siloxane-polyether copolymer (synthesized from vegetable oil), which is PFAS-free and has a surface tension of ≤28mN / m. It can improve the nucleation uniformity of polyurethane foam by about 20%, while avoiding the environmental residue problems of traditional PFAS-containing silicone oils.

[0118] (ii) Achieving high fluidity and rapid curing to adapt to ultra-thin designs 1. This application introduces a bio-based ester viscosity modifier (e.g., bio-based diethyl adipate-propylene glycol ester). This bio-based ester viscosity modifier can reduce the material viscosity to 280 mPa during the initial foaming stage (0s~60s). s~320mPa The flow index is ≥0.88cm / g at 20℃, which improves the flowability of the foaming liquid in the ultra-thin mold and meets the requirements of ultra-thin design. In addition, the bio-based ester viscosity modifier will automatically cross-link with the temperature increase in the later stage of foaming (60s~120s) without affecting the strength of polyurethane foam.

[0119] 2. This application optimizes the proportion of foaming catalysts by using catalysts such as pentamethyldiethylenetriamine, bio-based amine additives, dimethylcyclohexylamine, and temperature-responsive nanocarriers. This can extend the milky whitening time to 10s~12s (expanding the flow window by about 30% to ensure sufficient flow of the foaming liquid) and shorten the gel time to 38s~40s (increasing the curing efficiency by 15%), thus achieving a balance between high fluidity and rapid curing.

[0120] (III) Achieving rapid demolding and dimensional stability control in low-temperature environments 1. This application introduces a low-temperature active additive (e.g., N-ethylmorpholine) into the catalyst 2-hydroxypropyltrimethylformate. The low-temperature active additive can form hydrogen bonds with 2-hydroxypropyltrimethylformate, increasing the catalyst activity by 40% to 50% at 15℃ to 25℃. Unlike the traditional technology that sacrifices strength for low-temperature demolding, the compressive strength of the polyurethane foam in this application is still ≥158kPa, ensuring a demolding time of <140s, achieving efficient demolding under low-temperature molds. When the mold temperature is 30℃ to 40℃, the low-temperature active additive will automatically deactivate, avoiding embrittlement of the polyurethane foam caused by over-catalysis.

[0121] 2. This application, by adding a nucleating agent (such as polycaprolactone) during the preparation of bio-based polyols, can regulate the crystallinity of modified starch-based polyols, so that the dimensional change rate of polyurethane foam is ≤0.3% at -30℃ and ≤0.6% under 60℃ / 95%RH conditions, thereby achieving stable dimensional control at low temperatures and solving the problem of excessive shrinkage and deformation of the box after low-temperature demolding of polyurethane foam.

[0122] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0123] The above provides a detailed description of the foaming agent composition, combined polyether, polyurethane composition, polyurethane foam, and refrigeration equipment provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A foaming agent composition, characterized in that, It includes a foaming agent and a foam stabilizer, wherein the foaming agent includes bio-based cyclopentane and CO2-based foaming agents, and the foam stabilizer includes bio-based siloxane-polyether copolymers.

2. The foaming agent composition according to claim 1, characterized in that, The foaming agent composition comprises, by weight, 12 to 25 parts of the foaming agent and 1 to 4 parts of the foam stabilizer; And / or, the mass ratio of the bio-based cyclopentane to the CO2-based foaming agent is (8~12):(3~5); And / or, the CO2-based blowing agent includes a dimethyl carbonate derivative, which includes one or more of diethyl carbonate, methyl ethyl carbonate, methyl ethylene carbonate, dipropyl carbonate, and dimethyl carbonate-propylene oxide copolymer.

3. The foaming agent composition according to claim 1, characterized in that, The bio-based siloxane-polyether copolymer is prepared by the following method: alcoholysis of vegetable oil to obtain a bio-based polyol; and copolymerization reaction of the bio-based polyol, polyether monomer, siloxane monomer and first catalyst to obtain the bio-based siloxane-polyether copolymer.

4. The foaming agent composition according to claim 3, characterized in that, The surface tension of the bio-based siloxane-polyether copolymer is ≤28mN / m; And / or, the mass ratio of the bio-based polyol, the polyether monomer, and the siloxane monomer is (50~70):(20~30):(5~15), and the first catalyst accounts for 0.01%~0.1% of the total mass of the bio-based polyol, the polyether monomer, the siloxane monomer, and the first catalyst; And / or, the vegetable oil includes one or more of rapeseed oil, soybean oil, palm oil, flaxseed oil, cottonseed oil and sunflower oil; And / or, the polyether monomer includes one or more of the following: propylene oxide / ethane polymer, tetrahydrofuran homopolymer, epichlorohydrin polymer, epichlorohydrin-ethylene oxide copolymer, and glycidyl ether polyether; And / or, the siloxane monomer comprises one or more of octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, methyltrimethoxysilane, and vinyltriethoxysilane; And / or, the first catalyst comprises a first base catalyst or a platinum catalyst, wherein the first base catalyst comprises one or more of potassium hydroxide and sodium hydroxide, and the platinum catalyst comprises one or more of chloroplatinic acid, platinum-vinylsiloxane complex, platinum-cyclopentadiene complex, and platinum-phosphine ligand complex.

5. A composite polyether, characterized in that, It includes a polyol composition and a foaming agent according to any one of claims 1 to 4, wherein the polyol composition includes bio-based polyols.

6. The composite polyether according to claim 5, characterized in that, The bio-based polyol includes a modified starch-castor oil composite polyol and an epoxy compound grafted onto the modified starch-castor oil composite polyol, with a grafting rate of 30% to 40%.

7. The composite polyether according to claim 6, characterized in that, The bio-based polyol is prepared by the following method: starch is modified by esterification or etherification to obtain modified starch; the modified starch is dried at 100℃~110℃ for 2h-3h; castor oil is dehydrated by vacuum distillation at 110℃~120℃; the dehydrated castor oil and modified starch are mixed, a second base catalyst is added, the temperature is raised to 100℃~120℃, an epoxide compound is introduced, and the reaction is carried out at 0.3MPa~0.5MPa for 4h~6h; after neutralization, low-boiling substances are removed by vacuum, and the mixture is filtered to obtain the bio-based polyol.

8. The composite polyether according to claim 7, characterized in that, The epoxy compound includes one or more of propylene oxide, cyclohexane oxide, ethylene oxide, butane oxide, and phenyl glycidyl ether. And / or, the second alkaline catalyst includes one or more of potassium hydroxide and sodium hydroxide; And / or, the modified starch is prepared by the following method: mixing starch with esters or ethers and reacting at 60℃~90℃ for 2h~4h to obtain modified starch; And / or, the addition of the second base catalyst includes: adding a second base catalyst and a nucleating agent, wherein the nucleating agent includes one or more of polycaprolactone, polyethylene glycol, polylactide, butylene adipate, polytrimethylene carbonate, and polycaprolactone-polyethylene glycol block copolymer.

9. The combined polyether according to any one of claims 6 to 8, characterized in that, The bio-based polyol has a bio-based content of ≥70%, a hydroxyl value of 280mgKOH / g~320mgKOH / g, and a viscosity of 1500mPa at 25°C. s~2000mPa s.

10. The composite polyether according to claim 5, characterized in that, The combined polyether comprises 100 parts of the polyol composition by weight. And / or, by mass parts, the polyol composition comprises 20 to 30 parts of the bio-based polyol, 10 to 20 parts of sorbitol polyether, 18 to 25 parts of o-toluene diamine polyether, 10 to 22 parts of sucrose-propylene glycol composite polyether and 20 to 25 parts of glycerol polyether; And / or, by weight, the polyether composition further includes 0.5 to 3.5 parts of water.

11. The composite polyether according to claim 5, characterized in that, By weight, the polyether complex further includes 1 to 3.5 parts of catalyst and 1 to 3 parts of viscosity modifier. The catalyst includes pentamethyldiethylenetriamine, bio-based amine additive, dimethylcyclohexylamine, and temperature-responsive nanocarrier. The viscosity modifier includes bio-based esters.

12. The composite polyether according to claim 11, characterized in that, The mass ratio of the pentamethyldiethylenetriamine, the bio-based amine adjuvant, the dimethylcyclohexylamine, and the temperature-responsive nanocarrier is (0.1~6):(0.1~0.3):(0.5~7):(0.01~0.5). And / or, the bio-based amine adjuvant includes one or more of bio-based ethanolamine, chitosan-based amine adjuvants, soybean protein-based amines, bio-based propylamine, and bio-based butylamine; And / or, the temperature-responsive nanocarrier includes one or more of nano-silica, nano-titanium dioxide, poly(N-isopropylacrylamide) nanocarrier, chitosan nanoparticles, and gelatin nanoparticles; And / or, the bio-based esters include one or more of the following: bio-based diethyl adipate-propylene glycol ester, bio-based dioctyl adipate, bio-based dibutyl sebacate, bio-based diethyl malonate, bio-based dipropyl succinate, and bio-based tributyl citrate.

13. The composite polyether according to claim 11, characterized in that, The catalyst further includes ammonium 2-hydroxypropyltrimethylformate and a low-temperature active agent, wherein the mass ratio of ammonium 2-hydroxypropyltrimethylformate to the low-temperature active agent is (0.3~2):(0.1~0.3).

14. The composite polyether according to claim 13, characterized in that, The low-temperature active agent includes one or more of N-ethylmorpholine, zinc dithiocarbamate, pentamethyldiethylenetriamine, tetrabutyl titanate, and bio-based ethanolamine.

15. A polyurethane composition, characterized in that, It includes isocyanates and the polyether combinations according to any one of claims 5 to 14.

16. The polyurethane composition according to claim 15, characterized in that, The polyurethane composition comprises 120 to 135 parts of the isocyanate by weight; and / or the NCO content of the isocyanate is 31.0% ± 0.5%.

17. A polyurethane foam, characterized in that, The polyurethane foam is obtained by foaming the polyurethane composition according to any one of claims 15 to 16.

18. The polyurethane foam according to claim 17, characterized in that, The GWP of the polyurethane foam is less than 100. And / or, the thermal conductivity of the polyurethane foam at 10°C is ≤17.8 mW / (m²). K); And / or, the core density of the polyurethane foam is 26.0 kg / m³ to 27.5 kg / m³, and the compressive strength of the polyurethane foam is ≥158 kPa; And / or, the dimensional change rate of the polyurethane foam at -30℃ / 24h is ≤0.3%, and the dimensional change rate of the polyurethane foam at 60℃ / 95%RH is ≤0.6%.

19. A refrigeration device, characterized in that, The refrigeration equipment includes an insulation layer, which is made of polyurethane foam as described in any one of claims 17-18.

Images