Polyether and preparation method thereof, polyurethane composition, polyurethane foam and preparation method thereof

Abstract

The invention provides polyether and a preparation method thereof, a polyurethane composition, polyurethane foam and a preparation method thereof. The polyether is prepared from the following raw materials in parts by mass: 39 to 41 parts of cane sugar, 9 to 11 parts of glycerol, 7 to 9 parts of tris (2-hydroxyethyl) isocyanurate and 4 to 6 parts of pentaerythritol, and the epoxy monomer is prepared from 12.51 to 14.21 parts of epoxypropane. According to the invention, the viscosity of the polyether can be reduced while the high branching degree of the polyether is ensured, so that the polyether can meet the ultra-thin filling requirement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyurethane, and particularly relates to a polyether and a preparation method thereof, a polyurethane composition, and a polyurethane foam and a preparation method thereof. BACKGROUND

[0002] With the development of society, refrigeration equipment such as refrigerators gradually develops in the direction of ultra-thin, in order to save installation space. In order to thin the thickness of the thermal insulation layer (polyurethane foam) of the refrigeration equipment such as refrigerator, it is necessary to make the polyether used for preparing the polyurethane foam meet the ultra-thin filling requirement, for example, the wall thickness of the household ultra-thin refrigerator is 12mm~15mm, and the polyether for preparing the polyurethane foam is required to have a viscosity ≤900mPa s, but the existing polyether has the defect of too high viscosity (≥1100mPa s), which leads to the easy occurrence of filling holes (for example, the 15mm thin wall filling rate ≤92%), and cannot meet the ultra-thin filling requirement. SUMMARY

[0003] The present application provides a polyether and a preparation method thereof, a polyurethane composition, and a polyurethane foam and a preparation method thereof, to solve the problem of too high viscosity of the existing polyether, which cannot meet the ultra-thin filling requirement.

[0004] In a first aspect, the present application provides a polyether, raw materials of the polyether include a starter and an epoxy monomer, the starter includes sucrose 39 parts~41 parts, glycerol 9 parts~11 parts, tri (2-hydroxyethyl) isocyanurate 7 parts~9 parts, and pentaerythritol 4 parts~6 parts in terms of mass fraction, and the epoxy monomer includes epoxy propane 12.51 parts~14.21 parts.

[0005] Optionally, the epoxy monomer further includes epoxy cyclohexane 6.8 parts~7.73 parts in terms of mass fraction.

[0006] Optionally, the epoxy monomer further includes phenyl glycidyl ether 10.78 parts~12.24 parts and oxirane 4.62 parts~5.24 parts in terms of mass fraction.

[0007] Optionally, the raw materials of the polyether further include a catalyst, the catalyst includes a zinc-cobalt double metal cyanide complex and tri (dimethylaminopropyl) amine, the mass of the zinc-cobalt double metal cyanide complex is 0.035%~0.045% of the mass of the starter, and the mass of the tri (dimethylaminopropyl) amine is 0.05%~0.07% of the mass of the starter.

[0008] Optionally, the catalyst further comprises dibutyl zinc and / or dimethyl ethanol amine, the mass of the dibutyl zinc is 0.012%~0.018% of the mass of the initiator, the mass of the dimethyl ethanol amine is 0.02%~0.03% of the mass of the initiator; and / or, the mass fraction of the catalyst is 0.129 parts~0.171 parts.

[0009] Optionally, the hydroxyl value of the polyether is 260 mg KOH / g~280 mg KOH / g, the viscosity of the polyether at 25℃ is 700 mPa·s~900 mPa·s; and / or, in the polyether, the alicyclic ring density is 32%~38%, the aromatic ring density is 25%~28%, and the primary hydroxyl content is ≥90%; and / or, the polyether further comprises antioxidant 0.2 parts~0.3 parts in terms of mass fraction.

[0010] In a second aspect, the embodiments of the present application further provide a preparation method of a polyether, the preparation method of the polyether comprising the following steps: mixing an initiator and an epoxy monomer to obtain a polyether; In terms of mass fraction, the initiator comprises sucrose 39 parts~41 parts, glycerol 9 parts~11 parts, tri (2-hydroxyethyl) isocyanurate 7 parts~9 parts, and pentaerythritol 4 parts~6 parts, and the epoxy monomer comprises propylene oxide 12.51 parts~14.21 parts.

[0011] Optionally, the preparation method of the polyether comprises the following steps: (1) adding an initiator into a reaction kettle for activation; (2) adding a first part of catalyst and a first part of epoxy monomer into the reaction kettle, reacting for a first time at a first temperature, the first part of epoxy monomer comprising a first batch of propylene oxide; (3) continuously adding a second part of catalyst and a second part of epoxy monomer into the reaction kettle, reacting for a second time at a second temperature, the second temperature being greater than the first temperature, the second part of epoxy monomer comprising a second batch of propylene oxide, and the addition amount of the second batch of propylene oxide being less than that of the first batch of propylene oxide; (4) continuously adding a third part of epoxy monomer into the reaction kettle, the third part of epoxy monomer comprising a third batch of propylene oxide, and reacting at the second temperature, the addition amount of the third batch of propylene oxide being less than that of the second batch of propylene oxide; (5) continuously adding a third part of catalyst and a fourth part of epoxy monomer into the reaction kettle, reacting for a third time at a third temperature, the third temperature being greater than the second temperature, the fourth part of epoxy monomer comprising a fourth batch of propylene oxide, and the addition amount of the fourth batch of propylene oxide being less than that of the third batch of propylene oxide; (6) removing unreacted epoxy monomers and catalyst to obtain polyether.

[0012] Optionally, the first batch of propylene oxide is 6.25 parts to 7.11 parts, the second batch of propylene oxide is 4.37 parts to 4.98 parts, the third batch of propylene oxide is 0.96 parts to 1.1 parts, and the fourth batch of propylene oxide is 0.91 parts to 1.04 parts; and / or, the first part of the epoxy monomer further comprises a first batch of epoxy cyclohexane, the mass fraction of the first batch of epoxy cyclohexane is 3.3 parts to 3.76 parts; the second part of the epoxy monomer further comprises a second batch of epoxy cyclohexane, the mass fraction of the second batch of epoxy cyclohexane is 2.42 parts to 2.77 parts; the third part of the epoxy monomer further comprises a third batch of epoxy cyclohexane, the mass fraction of the third batch of epoxy cyclohexane is 0.54 parts to 0.62 parts; the fourth part of the epoxy monomer further comprises a fourth batch of epoxy cyclohexane, the mass fraction of the fourth batch of epoxy cyclohexane is 0.52 parts to 0.6 parts; and / or, the third part of the epoxy monomer further comprises phenyl glycidyl ether 10.78 parts to 12.06 parts and oxirane 4.62 parts to 5.17 parts; and / or, the first part of the catalyst comprises a first batch of zinc-cobalt double metal cyanide complex and dibutyl zinc, the addition amount of the first batch of zinc-cobalt double metal cyanide complex is 60% of the total mass of the zinc-cobalt double metal cyanide complex, the total mass of the zinc-cobalt double metal cyanide complex is 0.035% to 0.045% of the mass of the starter, and the mass of the dibutyl zinc is 0.012% to 0.018% of the mass of the starter; the second part of the catalyst comprises a second batch of zinc-cobalt double metal cyanide complex and tri(dimethylaminopropyl)amine, the mass of the tri(dimethylaminopropyl)amine is 0.05% to 0.07% of the mass of the starter, and the addition amount of the second batch of zinc-cobalt double metal cyanide complex is 30% of the total mass of the zinc-cobalt double metal cyanide complex; the third part of the catalyst comprises a third batch of zinc-cobalt double metal cyanide complex and dimethylethanolamine, the mass of the dimethylethanolamine is 0.02% to 0.03% of the mass of the starter, and the addition amount of the third batch of zinc-cobalt double metal cyanide complex is 10% of the total mass of the zinc-cobalt double metal cyanide complex; and / or, the first temperature is 73°C to 77°C, and the first time is 1h to 1.2h; and / or, the second temperature is 78°C to 82°C, and the second time is 2h to 2.2h; and / or, the third temperature is 83°C to 87°C, and the third time is 1h to 1.2h.

[0013] Optionally, the step (1) comprises: adding a starter into a microwave reactor, vacuumizing to -0.095 MPa to -0.098 MPa, replacing with nitrogen for multiple times, heating to 73℃ to 77℃, microwave stirring and keeping for 30 min to 35 min, and the stirring speed is 300 rpm to 350 rpm; and / or, the reaction pressure of the step (2) is 0.3 MPa to 0.4 MPa; and / or, the reaction pressure of the step (3) is 0.4 MPa to 0.5 MPa; and / or, the reaction pressure of the step (4) and the step (5) is 0.5 MPa to 0.6 MPa; and / or, the step (6) comprises: degassing the product of the step (5) at 78℃ to 82℃ under a vacuum degree of -0.095 MPa to -0.098 MPa for 1 h to 1.5 h, and then filtering to obtain the polyether.

[0014] In a third aspect, the embodiments of the present application further provide a polyurethane composition, which comprises an A component and a polymethylpolphenyl polyisocyanate, the A component comprises a polyether and a blowing agent, the polyether is the polyether described above, or the polyether is prepared by the preparation method of the polyether described above.

[0015] Optionally, in the A component, the mass ratio of the polyether to the blowing agent is 100:(21.8-26.2); and / or, the mass ratio of the A component to the polymethylpolphenyl polyisocyanate is 1:(1.17-1.19); and / or, the blowing agent comprises HFO-1336mzz 13 parts to 15 parts, cyclopentane 7 parts to 9 parts, isobutane 1.0 part to 1.5 part, and methylpentane 0.8 part to 1.0 part by mass fraction; and / or, the GWP of the blowing agent is ≤15; and / or, the A component further comprises an interfacial control agent 0.5 part to 0.7 part by mass fraction, the interfacial control agent comprises one or more of polyfluorobutyl methacrylate, hexafluorobutyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, monoalkoxy titanate, polyfluoroalkyl acrylate, and polyethylene glycol diacrylate-butyl acrylate copolymer; and / or, the A component further comprises a nucleating agent 0.6 part to 0.8 part by mass fraction, the nucleating agent comprises one or more of FA-188, PF5050, PF5060, and PF5056 produced by 3M Company; and / or, the A component further comprises polyethylene glycol diacrylate 0.2 part to 0.4 part by mass fraction; and / or, the A component further comprises nitrile butadiene rubber powder 0.7 part to 0.9 part by mass fraction, and the particle size of the nitrile butadiene rubber powder is 450 nm to 550 nm.

[0016] In a fourth aspect, the embodiments of the present application further provide a polyurethane foam, which is prepared by foaming the polyurethane composition described above.

[0017] Optionally, the polyurethane foam has a shrinkage rate of ≤0.4% at -80℃ for 24h, a 15mm thin-wall filling rate of ≥99%, a thermal conductivity of ≤14mW / (m K) at 10℃, and a compressive strength of ≥0.23MPa.

[0018] In a fifth aspect, the embodiments of the present application further provide a preparation method of the polyurethane foam, the preparation method of the polyurethane comprising the following steps: mixing the polyether with a blowing agent to obtain a component A, the polyether being the polyether described above or the polyether prepared by the preparation method of the polyether described above; mixing the component A with a polymethylpolphenyl polyisocyanate, and injecting the mixture into a foaming mold to foam, to obtain the polyurethane foam.

[0019] Optionally, the mixing of the polyether with the blowing agent comprises: adding the polyether into an ultrasonic vacuum stirring kettle, heating to 50-55℃, adding the blowing agent and a nucleating agent or adding the blowing agent, the nucleating agent and an interface control agent, and performing ultrasonic vacuum stirring treatment to obtain the component A; mixing the component A with the polymethylpolphenyl polyisocyanate, and injecting the mixture into a foaming mold, and sequentially performing hot air curing treatment, low-temperature setting treatment and normal-temperature curing treatment, to obtain the polyurethane foam; Optionally, the ultrasonic power of the ultrasonic vacuum stirring treatment is 340-360W, the ultrasonic frequency is 20-21kHz, the vacuum degree is -0.092MPa to -0.095MPa, and the stirring time is 38-42min; and / or, the temperature of the hot air curing treatment is 57-63℃, and the time is 2-2.2h; and / or, the temperature of the low-temperature setting treatment is -8- -12℃, and the time is 1-1.2h; and / or, the temperature of the normal-temperature curing treatment is 23-28℃, and the time is 20-22h.

[0020] The polyether provided by the embodiments of the present application has raw materials including a starter, an epoxy monomer and a catalyst, by setting the starter to include sucrose, glycerol, tris(2-hydroxyethyl) isocyanurate and pentaerythritol, the epoxy monomer to include propylene oxide, and controlling the proportions of the raw materials within a suitable range, the sucrose, glycerol, tris(2-hydroxyethyl) isocyanurate and pentaerythritol can form a multi-hydroxyl rigid core cluster with more branching points through hydrogen bonding, effectively improving the branching degree of the polyether, and the viscosity of the polyether is balanced by the propylene oxide, effectively reducing the viscosity of the polyether, so that the high branching degree of the polyether is ensured while the viscosity of the polyether is reduced, and the polyether can meet the ultra-thin filling demand. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description only show some of the embodiments of the present application, and all other drawings obtained by those skilled in the art without creative effort based on these drawings are within the scope of the present application.

[0022] Figure 1 The flow chart of the preparation method of the polyether provided in the embodiments of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present application.

[0024] In the description of the present application, the orientation words such as "upper" and "lower" are the directions of the drawing surface in the drawings. In addition, in the description of the present application, the term "comprising" means "including but not limited to". The term "exemplary" is used to mean "serving as an example, instance or illustration" and any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The term "and / or" includes any and all combinations of one or more of the associated listed items. The terms "first", "second" are used only for the purpose of description and should not be understood as indicating or implying relative importance or implying the number of the indicated technical features, so that the features with "first", "second" can explicitly or implicitly include one or more of the features.

[0025] The various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit to the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the 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 described range, such as 1, 2, 3, 4, 5 and 6, which is applicable to any range.

[0026] With the development of refrigeration equipment such as refrigerator towards "ultra-low temperature, ultra-thin, high environmental protection", the existing polyurethane insulation material faces multiple technical bottlenecks, for example: in order to meet the ultra-thin filling demand of polyether used for preparing polyurethane foam, it is necessary to reduce the viscosity of polyether, but the existing polyether has the problem of contradiction between high branching degree and low viscosity (high branching degree and high viscosity).

[0027] In order to solve the problem of contradiction between high branching degree and low viscosity of the existing polyether, the embodiment of the present application provides a kind of polyether, the raw material of the polyether includes initiator and epoxy monomer, by mass fraction, the initiator includes sucrose 39~41, glycerol 9~11, tri (2-hydroxyethyl) isocyanuric acid ester (abbreviated as THEIC) 7~9 and pentaerythritol 4~6, the epoxy monomer includes epoxy propane (abbreviated as PO) 12.51~14.21.

[0028] The polyether provided by the embodiment of the present application, by setting the initiator to include sucrose, glycerol, tri (2-hydroxyethyl) isocyanuric acid ester and pentaerythritol, and the epoxy monomer to include epoxy propane, and controlling the proportion of each raw material within a suitable range, the sucrose, glycerol, tri (2-hydroxyethyl) isocyanuric acid ester and pentaerythritol in it can form a multi-hydroxyl rigid core cluster with more branching points through hydrogen bonding association, effectively improving the branching degree of polyether, and at the same time balancing the viscosity of polyether through epoxy propane, effectively reducing the viscosity of polyether, so as to realize the reduction of the viscosity of polyether while ensuring the high branching degree of polyether, that is, to realize high branching and low viscosity at the same time, so that the polyether can meet the ultra-thin filling demand, and solve the problem of contradiction between high branching degree and low viscosity of the existing polyether.

[0029] Specifically, the hydroxyl value of the polyether is 260mg KOH / g~280mg KOH / g, and the viscosity of the polyether at 25℃ is 700mPa·s~900mPa·s. Exemplarily, the hydroxyl value of the polyether can be 260mg KOH / g, 265mg KOH / g, 270mg KOH / g, 275mg KOH / g or 280mg KOH / g, etc.; the viscosity (25℃) of the polyether can be 700mPa·s, 750mPa·s, 800mPa·s, 850mPa·s or 900mPa·s, etc. By controlling the viscosity of the polyether at 25℃ to be 700mPa·s~900mPa·s, the 15mm thin-wall filling rate of the polyurethane foam prepared by using the polyether can be ≥99%, which meets the 15mm thin-wall filling demand, while the existing polyurethane foam has the problem of 15mm thin-wall filling rate ≤92%.

[0030] Exemplarily, the mass fraction of sucrose can be 39 parts, 39.5 parts, 40 parts, 40.5 parts or 41 parts, the mass fraction of glycerol can be 9 parts, 9.5 parts, 10 parts, 10.5 parts or 11 parts, etc., the mass fraction of tri (2-hydroxyethyl) isocyanurate can be 7 parts, 7.5 parts, 8 parts, 8.5 parts or 9 parts, etc., the mass fraction of pentaerythritol can be 4 parts, 4.5 parts, 5 parts, 5.5 parts or 6 parts, etc.; the mass fraction of propylene oxide can be 12.51 parts, 12.75 parts, 13 parts, 13.36 parts or 14.21 parts, etc.

[0031] It can be understood that the existing polyether has insufficient branching points of starting agent, and has the defect of “high branching leading to high viscosity”. The starting agent of the present application adopts sucrose, glycerol, tri (2-hydroxyethyl) isocyanurate and pentaerythritol, and the mass ratio of the four is (39~41) (9~11) : (7~9) : (4~6), so that the functionality is increased to 6.0~6.5, and a “multihydroxyl rigid core cluster” is formed by hydrogen bond association, thereby effectively increasing the branching degree of the polyether, wherein the isocyanurate ring of tri (2-hydroxyethyl) isocyanurate and the four hydroxyl groups of pentaerythritol provide uniform branching points; moreover, the epoxy monomer of the present application adopts the above-mentioned propylene oxide, and the flexible chain of propylene oxide can balance the viscosity, which is conducive to reducing the viscosity of the polyether.

[0032] In some embodiments of the present application, the epoxy monomer further includes cyclohexene oxide (CHO) 6.8 parts~7.73 parts by mass fraction. Exemplarily, the mass fraction of cyclohexene oxide can be 6.8 parts, 6.9 parts, 7 parts, 7.1 parts, 7.26 parts, 7.3 parts, 7.4 parts, 7.5 parts, 7.61 parts or 7.73 parts, etc. The epoxy monomer of the present application adopts the above-mentioned cyclohexene oxide, and cyclohexene oxide and propylene oxide can form “PO-CHO-PO-CHO” alternating segments, so that the alicyclic density in the polyether is increased to about 35%, thereby reducing the thermal conductivity, so that the thermal conductivity of the polyurethane foam is ≤14 mW / (m K) at 10℃, and the thermal conductivity is ≤25 mW / (m·K) at -80℃.

[0033] Optionally, the epoxy monomer further comprises phenyl glycidyl ether (PGE) 10.78-12.24 parts and ethylene oxide (EO) 4.62-5.24 parts. For example, the mass fraction of the phenyl glycidyl ether can be 10.78 parts, 10.98 parts, 11.15 parts, 11.3 parts, 11.51 parts, 11.8 parts, 12.06 parts or 12.24 parts, etc.; the mass fraction of the ethylene oxide can be 4.62 parts, 4.71 parts, 4.82 parts, 4.93 parts, 5.02 parts, 5.17 parts or 5.24 parts, etc. By using the above-mentioned phenyl glycidyl ether and ethylene oxide, the epoxy monomer of the present application continuously grafts two adjacent phenyl glycidyl ethers, so that the aromatic ring density in the polyether is 25%-28%, thereby improving the rigidity of the polyurethane foam prepared by using the polyether of the present application, and further improving the compression strength of the polyurethane foam, so that the compression strength of the polyurethane foam is ≥0.23 MPa; at the same time, the primary hydroxyl group (primary hydroxyl group content ≥90%) of the ethylene oxide can improve the reactivity of the polyether, solve the contradiction of "high rigidity and low reactivity", and meet the demand of cost and performance balance.

[0034] In some embodiments of the present application, in the polyether, the alicyclic ring density is 32%-38% (for example, 32%, 33%, 34%, 35%, 36%, 37% or 38%, etc.), the aromatic ring density is 25%-28% (for example, 25%, 25.2%, 25.5%, 25.8%, 26%, 26.2%, 26.5%, 26.8%, 27%, 27.2%, 27.5%, 27.8% or 28%, etc.), and the primary hydroxyl group content is ≥90%.

[0035] Optionally, the sucrose is of analytical grade, the hydroxyl value of the sucrose can be 1100 mg KOH / g-1300 mg KOH / g (for example, 1100 mg KOH / g, 1200 mg KOH / g or 1300 mg KOH / g, etc.), the purity of the glycerol is ≥99.5%, the tri(2-hydroxyethyl) isocyanurate is of industrial grade, the purity of the tri(2-hydroxyethyl) isocyanurate is ≥98%, the purity of the pentaerythritol is ≥99%, the purity of the propylene oxide is ≥99.9%, the purity of the cyclohexene oxide is ≥99.5%, the phenyl content of the phenyl glycidyl ether is 65%-75% (for example, 65%, 70% or 75%, etc.), and the purity of the ethylene oxide is ≥99.9%.

[0036] In some embodiments of the present application, the raw material of the polyether further comprises a catalyst, the catalyst comprising a zinc-cobalt double metal cyanide complex (referred to as Zn-Co type DMC) and tri(dimethylaminopropyl)amine (referred to as TDPA), the mass of the zinc-cobalt double metal cyanide complex being 0.035% to 0.045% of the mass of the initiator, and the mass of the tri(dimethylaminopropyl)amine being 0.05% to 0.07% of the mass of the initiator. Among them, the zinc-cobalt double metal cyanide complex can activate the ring opening of the epoxy monomer, control the molecular weight distribution, and reduce the PDI to 1.1 to 1.3; the tri(dimethylaminopropyl)amine can promote the ring opening of the ethylene oxide, increase the content of the primary hydroxyl group in the polyether, so that the content of the primary hydroxyl group is ≥90% (the existing technology is ≤70%), thereby improving the reaction activity of the polyether (the reaction activity with isocyanate is increased by about 30%, and the gel time is ≤90s).

[0037] Exemplarily, the mass of the zinc-cobalt double metal cyanide complex can be 0.035%, 0.036%, 0.037%, 0.038%, 0.039%, 0.04%, 0.041%, 0.042%, 0.043%, 0.044%, 0.045% or the like of the mass of the initiator; and the mass of the tri(dimethylaminopropyl)amine can be 0.05%, 0.055%, 0.06%, 0.65% or 0.07% or the like of the mass of the initiator.

[0038] In order to meet the ultra-low temperature (-80℃) stability requirement, the insulation layer (polyurethane foam) of the refrigeration equipment such as commercial deep-freezing refrigerator and biological sample refrigerator needs to have no obvious shrinkage at extremely low temperature, but the existing polyurethane foam has a shrinkage rate of ≥1.2% at -80℃ for 24h, which is easy to cause the insulation layer to crack and the refrigeration efficiency to drop sharply. In some embodiments of the present application, the catalyst further comprises dibutyl zinc (referred to as DBZ) and / or dimethyl ethanolamine (referred to as DMEA), the mass of the dibutyl zinc being 0.012% to 0.018% of the mass of the initiator, and the mass of the dimethyl ethanolamine being 0.02% to 0.03% of the mass of the initiator. By adding dibutyl zinc as a catalyst, the dibutyl zinc can preferentially combine with the epoxy group of the epoxy cyclohexane and the phenyl glycidyl ether, so as to increase the insertion rate of the rigid monomer (epoxy cyclohexane), so that the insertion rate of the rigid monomer is increased to 75% to 80% (the insertion rate of the rigid monomer in the existing technology is ≤30%), thereby improving the rigidity of the polyurethane foam, and the polyurethane foam has no obvious shrinkage at -80℃ low temperature.

[0039] Optionally, the catalyst further comprises dimethyl ethanolamine (DMEA) with a mass of 0.02%-0.03% of the mass of the initiator. The existing polyurethane foam preparation has a reaction temperature of ≥110°C, and has the problem of high energy consumption. By adding dimethyl ethanolamine as a catalyst, the dimethyl ethanolamine can reduce the activation energy of the zinc-cobalt double metal cyanide complex, thereby reducing the reaction temperature to about 72°C-87°C, thereby reducing the energy consumption by about 20% (calculated according to the heating power of the reaction kettle).

[0040] For example, the mass of the dibutyl zinc can be 0.012%, 0.013%, 0.014%, 0.015%, 0.017%, 0.016% or 0.018% of the mass of the initiator; and the mass of the dimethyl ethanolamine can be 0.02%, 0.021%, 0.022%, 0.023%, 0.024%, 0.025%, 0.026%, 0.027%, 0.028% or 0.03% of the mass of the initiator.

[0041] In some embodiments of the present application, the total mass fraction of the catalyst is 0.129-0.171 parts. For example, the total mass fraction of the catalyst can be 0.129, 0.135, 0.14, 0.147, 0.15, 0.155, 0.16, 0.165 or 0.171 parts, etc.

[0042] Optionally, the zinc-cobalt double metal cyanide complex is of industrial grade, the dibutyl zinc is selected from a 10% toluene solution of dibutyl zinc, the purity of the tris(dimethylaminopropyl)amine is ≥99%, and the purity of the dimethyl ethanolamine is ≥99%.

[0043] In some embodiments of the present application, the polyether further comprises an antioxidant in an amount of 0.2-0.3 parts by mass. By adding an antioxidant, high-temperature aging can be inhibited. For example, the mass fraction of the antioxidant can be 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 or 0.3 parts, etc., which can be set according to actual needs.

[0044] Optionally, the antioxidant comprises one or more of antioxidant 1010 and antioxidant 168. For example, the antioxidant comprises antioxidant 1010 and antioxidant 168, and the mass ratio of the antioxidant 1010 to the antioxidant 168 is 2:1.

[0045] In summary, the polyether provided by the present application has the following beneficial effects, but is not limited to: 1. Initiator constructs "rigid core cluster": the initiator includes sucrose 39-41 parts by mass, glycerol 9-11 parts, tris (2-hydroxyethyl) isocyanurate 7-9 parts and pentaerythritol 4-6 parts, which are associated by hydrogen bond to form a "multihydroxy rigid core cluster"; wherein sucrose provides 8 hydroxyl groups as a branched skeleton, glycerol (3 hydroxyl groups) relieves the core density, tris (2-hydroxyethyl) isocyanurate isocyanurate ring (rigid group) improves core rigidity, and pentaerythritol (4 hydroxyl groups) supplements peripheral branching points, so that the overall functionality of the initiator reaches 6.0-6.5, laying a foundation for high branching.

[0046] 2. Epoxy monomer realizes "gradient branching" and "rigid controllable": propylene oxide (12.51-14.21 parts by mass) as a basic flexible monomer, forms a flexible chain segment to balance the viscosity; cyclohexene oxide (6.8-7.73 parts by mass) as a rigid alicyclic monomer, alternately grafted with propylene oxide to form "PO-CHO-PO-CHO" segments, so that the alicyclic density is increased to 32%-38%, reducing the thermal conductivity; phenyl glycidyl ether (10.78-12.24 parts by mass) as a rigid aromatic monomer, continuously grafted in the latter segment of the chain segment, forming a "PGE-PGE" continuous structure, so that the aromatic ring density reaches 25%-28%, which is conducive to improving the rigidity of the polyurethane foam; ethylene oxide (4.62-5.24 parts by mass) as an activity enhancing monomer, grafted at the end of the chain segment, so that the content of primary hydroxyl group is ≥90%, solving the problem of "high rigidity and low reaction activity".

[0047] 3. Catalyst synergistically regulates the insertion rate of rigid monomer and reaction efficiency: in the catalyst, the mass of zinc-cobalt double metal cyanide complex is 0.035%-0.045% of the mass of the initiator, which can activate the ring opening of the epoxy monomer and control the molecular weight distribution (PDI=1.1-1.3); the mass of tris (dimethylaminopropyl) amine is 0.05%-0.07% of the mass of the initiator, which can promote the ring opening of ethylene oxide and increase the content of primary hydroxyl group; the mass of dibutyl zinc is 0.012%-0.018% of the mass of the initiator, which can preferentially bind the epoxy groups of cyclohexene oxide and phenyl glycidyl ether, so that the insertion rate of rigid monomer reaches 75%-80%; the mass of dimethyl ethanolamine is 0.02%-0.03% of the mass of the initiator, which can reduce the catalytic activation energy of zinc-cobalt double metal cyanide complex, so that the reaction temperature is reduced to 73-87°C (energy consumption is reduced by about 20%).

[0048] 4. The mass fraction of antioxidant is 0.2-0.3 parts, which can inhibit high temperature aging.

[0049] The embodiment of the present application further provides a preparation method of the polyether, which comprises the following steps: mixing a starting agent and an epoxy monomer to obtain the polyether; the starting agent comprises 39-41 parts of sucrose, 9-11 parts of glycerol, 7-9 parts of tri (2-hydroxyethyl) isocyanurate (THEIC) and 4-6 parts of pentaerythritol in terms of mass fraction; and the epoxy monomer comprises 12.51-14.21 parts of propylene oxide.

[0050] For example, the mass fraction of the sucrose can be 39 parts, 39.5 parts, 40 parts, 40.5 parts or 41 parts, the mass fraction of the glycerol can be 9 parts, 9.5 parts, 10 parts, 10.5 parts or 11 parts, the mass fraction of the tri (2-hydroxyethyl) isocyanurate can be 7 parts, 7.5 parts, 8 parts, 8.5 parts or 9 parts, the mass fraction of the pentaerythritol can be 4 parts, 4.5 parts, 5 parts, 5.5 parts or 6 parts, and the mass fraction of the propylene oxide can be 12.51 parts, 12.75 parts, 13 parts, 13.36 parts or 14.21 parts.

[0051] In some embodiments of the present application, as shown in Figure 1 The preparation method of the polyether specifically comprises the following steps: (1) adding the starting agent into a reaction kettle for activation; (2) adding a first part of catalyst and a first part of epoxy monomer into the reaction kettle, reacting at a first temperature for a first time, wherein the first part of epoxy monomer comprises a first batch of propylene oxide; (3) continuously adding a second part of catalyst and a second part of epoxy monomer into the reaction kettle, reacting at a second temperature for a second time, wherein the second temperature is greater than the first temperature, the second part of epoxy monomer comprises a second batch of propylene oxide, and the addition amount of the second batch of propylene oxide is less than that of the first batch of propylene oxide; (4) continuously adding a third part of epoxy monomer into the reaction kettle, wherein the third part of epoxy monomer comprises a third batch of propylene oxide, and the reaction is carried out at the second temperature, and the addition amount of the third batch of propylene oxide is less than that of the second batch of propylene oxide; (5) continuously adding a third part of catalyst and a fourth part of epoxy monomer into the reaction kettle, reacting at a third temperature for a third time, wherein the third temperature is greater than the second temperature, the fourth part of epoxy monomer comprises a fourth batch of propylene oxide, and the addition amount of the fourth batch of propylene oxide is less than that of the third batch of propylene oxide; (6) removing unreacted epoxy monomer and catalyst to obtain the polyether.

[0052] The present application can control the insertion rhythm of propylene oxide by adding propylene oxide in four batches and adding catalyst in batches, avoid uneven distribution of epoxy monomer caused by single large addition, and finally realize the smooth rise of the branching degree gradient of polyether, that is, realize gradient branching. Moreover, the dosage of the four batches of propylene oxide decreases, which can realize the rise of the branching degree gradient while the viscosity is stable at 700mPa s~900mPa s, and the traditional process adopts single addition, resulting in viscosity ≥1100mPa s.

[0053] Optionally, the mass fraction of the first batch of propylene oxide is 6.25 parts to 7.11 parts, the mass fraction of the second batch of propylene oxide is 4.37 parts to 4.98 parts, the mass fraction of the third batch of propylene oxide is 0.96 parts to 1.1 parts, and the mass fraction of the fourth batch of propylene oxide is 0.91 parts to 1.04 parts.

[0054] Exemplarily, the mass fraction of the first batch of propylene oxide can be 6.25 parts, 6.35 parts, 6.45 parts, 6.55 parts, 6.68 parts, 6.75 parts, 6.85 parts, 6.95 parts or 7.11 parts, etc.; the mass fraction of the second batch of propylene oxide can be 4.37 parts, 4.47 parts, 4.58 parts, 4.68 parts or 4.98 parts, etc.; the mass fraction of the third batch of propylene oxide can be 0.96 parts, 1.0 parts, 1.03 parts, 1.06 parts or 1.1 parts, etc.; and the mass fraction of the fourth batch of propylene oxide can be 0.91 parts, 0.98 parts or 1.04 parts, etc.

[0055] Optionally, the first part of the epoxy monomer further comprises a first batch of epoxy cyclohexane, and the mass fraction of the first batch of epoxy cyclohexane is 3.3 parts to 3.76 parts; the second part of the epoxy monomer further comprises a second batch of epoxy cyclohexane, and the mass fraction of the second batch of epoxy cyclohexane is 2.42 parts to 2.77 parts; the third part of the epoxy monomer further comprises a third batch of epoxy cyclohexane, and the mass fraction of the third batch of epoxy cyclohexane is 0.54 parts to 0.62 parts; and the fourth part of the epoxy monomer further comprises a fourth batch of epoxy cyclohexane, and the mass fraction of the fourth batch of epoxy cyclohexane is 0.52 parts to 0.6 parts. By adding propylene oxide and epoxy cyclohexane in four batches, the present application can control the alternating insertion rhythm of propylene oxide and epoxy cyclohexane, avoid uneven distribution of epoxy monomer caused by single large addition, and finally realize the smooth rise of the branching degree gradient of polyether.

[0056] Exemplarily, the mass fraction of the first batch of epoxycyclohexane can be 3.3 parts, 3.35 parts, 3.4 parts, 3.45 parts, 3.52 parts, 3.55 parts, 3.6 parts, 3.65 parts or 3.76 parts, etc.; the mass fraction of the second batch of epoxycyclohexane can be 2.42 parts, 2.48 parts, 2.5 parts, 2.55 parts, 2.59 parts, 2.6 parts, 2.65 parts, 2.7 parts or 2.77 parts, etc.; the mass fraction of the third batch of epoxycyclohexane can be 0.54 parts, 0.55 parts, 0.56 parts, 0.57 parts, 0.58 parts, 0.59 parts, 0.6 parts, 0.61 parts or 0.62 parts, etc.; and the mass fraction of the fourth batch of epoxycyclohexane can be 0.52 parts, 0.53 parts, 0.54 parts, 0.55 parts, 0.56 parts, 0.57 parts, 0.58 parts, 0.59 parts or 0.6 parts, etc.

[0057] Optionally, the third part of the epoxy monomer further comprises phenyl glycidyl ether 10.78 parts to 12.24 parts and oxirane 4.62 parts to 5.24 parts in terms of mass fraction. Exemplarily, the mass fraction of the phenyl glycidyl ether can be 10.78 parts, 10.98 parts, 11.15 parts, 11.3 parts, 11.51 parts, 11.8 parts, 12.06 parts or 12.24 parts, etc.; and the mass fraction of the oxirane can be 4.62 parts, 4.71 parts, 4.82 parts, 4.93 parts, 5.02 parts, 5.17 parts or 5.24 parts, etc.

[0058] Optionally, the first part of the catalyst comprises a first batch of zinc-cobalt double metal cyanide complex and dibutyl zinc, the addition amount of the first batch of zinc-cobalt double metal cyanide complex is 60% of the total mass of the zinc-cobalt double metal cyanide complex, the total mass of the zinc-cobalt double metal cyanide complex is 0.035% to 0.045% of the mass of the starter, and the mass of the dibutyl zinc is 0.012% to 0.018% of the mass of the starter.

[0059] Exemplarily, the total mass of the zinc-cobalt double metal cyanide complex can be 0.035%, 0.036%, 0.037%, 0.038%, 0.039%, 0.04%, 0.041%, 0.042%, 0.043%, 0.044%, 0.045% of the mass of the starter, etc.; and the mass of the dibutyl zinc can be 0.012%, 0.013%, 0.014%, 0.015%, 0.017%, 0.016% or 0.018% of the mass of the starter, etc.

[0060] Optionally, the second part of the catalyst comprises a second batch of zinc cobalt double metal cyanide complex and tri(dimethylaminopropyl) amine, the mass of the tri(dimethylaminopropyl) amine is 0.05% to 0.07% of the mass of the initiator, and the amount of the second batch of zinc cobalt double metal cyanide complex added is 30% of the total mass of the zinc cobalt double metal cyanide complex.

[0061] Illustratively, the mass of the tri(dimethylaminopropyl) amine can be 0.05%, 0.055%, 0.06%, 0.65%, or 0.07% of the mass of the initiator, etc.

[0062] Optionally, the third part of the catalyst comprises a third batch of zinc cobalt double metal cyanide complex and dimethyl ethanolamine, the mass of the dimethyl ethanolamine is 0.02% to 0.03% of the mass of the initiator, and the amount of the third batch of zinc cobalt double metal cyanide complex added is 10% of the total mass of the zinc cobalt double metal cyanide complex.

[0063] Illustratively, the mass of the dimethyl ethanolamine can be 0.02%, 0.021%, 0.022%, 0.023%, 0.024%, 0.025%, 0.026%, 0.027%, 0.028%, 0.028%, or 0.03% of the mass of the initiator, etc.

[0064] Optionally, the first temperature is 73°C to 77°C, and the first time is 1h to 1.2h. Illustratively, the first temperature can be 73°C, 74°C, 75°C, 76°C, or 77°C, etc., and the first time can be 1h, 1.1h, or 1.2h, etc.

[0065] Optionally, the second temperature is 78°C to 82°C, and the second time is 2h to 2.2h. Illustratively, the second temperature can be 78°C, 79°C, 80°C, 81°C, or 82°C, etc., and the second time can be 2h, 2.1h, or 2.2h, etc. Optionally, the third temperature is 83°C to 87°C, and the third time is 1h to 1.2h. Illustratively, the third temperature can be 83°C, 84°C, 85°C, 86°C, or 87°C, etc., and the third time can be 1h, 1.1h, or 1.2h, etc.

[0066] In some embodiments of the present application, the total mass fraction of the catalyst is 0.129 parts to 0.171 parts. Illustratively, the total mass fraction of the catalyst can be 0.129 parts, 0.135 parts, 0.14 parts, 0.145 parts, 0.15 parts, 0.155 parts, 0.16 parts, 0.165 parts, or 0.171 parts, etc.

[0067] In some embodiments of the present application, the step (1) comprises: adding the initiator into a microwave reaction kettle, vacuumizing to-0.095 MPa to-0.098 MPa (for example, -0.095 MPa, -0.096 MPa, -0.097 MPa or-0.098 MPa, etc.), nitrogen replacement for multiple times (for example, 2 to 3 times); warming up to 73°C to 77°C (for example, 73°C, 74°C, 75°C, 76°C or 77°C, etc.), opening the microwave and stirring, keeping warm for 30 min to 35 min (for example, 30 min, 31 min, 32 min, 33 min, 34 min or 35 min, etc.), and the stirring speed is 300 rpm to 350 rpm (for example, 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm or 350 rpm, etc.). The step (1) can activate the initiator by opening the microwave, so that the dissociation degree of the hydroxyl group of the initiator is ≥95% (the traditional process without microwave, the dissociation degree is ≤85%), which lays a foundation for the uniform grafting of the subsequent monomer, so as to realize the improvement of 20% of the monomer grafting uniformity.

[0068] In the step (1), the power of microwave stirring can be 190 W to 210 W (for example, 190 W, 200 W or 210 W, etc.), and the microwave frequency can be 2.4 GHz to 2.5 GHz (for example, 2.4 GHz, 2.45 GHz or 2.5 GHz, etc.). It can be understood that through microwave stirring, the molecular vibration can be intensified, so that the epoxy monomer is inserted uniformly, so that the branching degree of the polyether is more stable. Alternatively, the reaction pressure of the step (2) is 0.3 MPa to 0.4 MPa, for example, it can be 0.3 MPa, 0.35 MPa or 0.4 MPa, etc.

[0069] Alternatively, the reaction pressure of the step (3) is 0.4 MPa to 0.5 MPa, for example, it can be 0.4 MPa, 0.45 MPa or 0.5 MPa, etc.

[0070] Alternatively, the reaction pressure of the step (4) and the step (5) is 0.5 MPa to 0.6 MPa, for example, it can be 0.5 MPa, 0.55 MPa or 0.6 MPa, etc.

[0071] Optionally, the step (6) comprises: degassing the product of step (5) at 78-82°C (for example 78°C, 79°C, 80°C, 81°C or 82°C, etc.), under a vacuum of -0.095 MPa to -0.098 MPa (for example -0.095 MPa, -0.096 MPa, -0.097 MPa or -0.098 MPa, etc.) for 1-1.5 hours (for example 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours or 1.5 hours, etc.), and then filtering to obtain the polyether. Through vacuum degassing and filtering, the polyether purity of the present application can be ≥99.8% and the impurity content is ≤0.2%; while the traditional process only degasses, resulting in an impurity content of ≥0.5%.

[0072] In some embodiments of the present application, the step (1) comprises: adding the initiator (sucrose 39-41 parts by mass fraction, glycerol 9-11 parts, tri (2-hydroxyethyl) isocyanurate 7-9 parts, pentaerythritol 4-6 parts) into a microwave reaction kettle, vacuuming to -0.095 MPa to -0.098 MPa, nitrogen replacement 2-3 times (remove oxygen to avoid side reactions), heating to 73-77°C, turning on the microwave and stirring (microwave frequency 2.4-2.5 GHz, microwave power 190-210 W, stirring speed 300-350 rpm) and keeping for 30-35 minutes. Step (1) through microwave makes the molecular vibration more intense, promotes the four components of the initiator to form hydrogen bond association, and the hydroxyl dissociation degree is ≥95% (≤85% for traditional process), which lays a foundation for uniform grafting of subsequent monomers.

[0073] The step (2) comprises: adding the first part of the catalyst and the first part of the epoxy monomer into the microwave reaction kettle, and reacting at 73-77°C and 0.3-0.4 MPa for 1-1.2 hours; wherein the first part of the catalyst comprises the first batch of zinc-cobalt double metal cyanide complex and dibutyl zinc, the addition amount of the first batch of zinc-cobalt double metal cyanide complex is 60% of the total mass of the zinc-cobalt double metal cyanide complex, the total mass of the zinc-cobalt double metal cyanide complex is 0.035-0.045% of the mass of the initiator, and the mass of the dibutyl zinc is 0.012-0.018% of the mass of the initiator; the first part of the epoxy monomer comprises the first batch of propylene oxide 6.25-7.11 parts by mass fraction and the first batch of epoxy cyclohexane 3.3-3.76 parts by mass fraction. Step (2) through dibutyl zinc preferentially binds the epoxy group of epoxy cyclohexane, ensures the preliminary formation of "PO-CHO" alternating segments, and makes the branching degree rise to about 0.45, and the insertion rate of rigid monomer (epoxy cyclohexane) is about 76.3% (gel permeation chromatography GPC analysis); The step (3) comprises: continuously adding a second part of catalyst and a second part of epoxy monomer into the microwave reactor, and reacting at 78-82 DEG C, 0.4-0.5 MPa for 2-2.2 h; wherein the second part of catalyst comprises a second batch of zinc-cobalt double metal cyanide complex and tri (dimethylaminopropyl) amine, the mass of the tri (dimethylaminopropyl) amine is 0.05-0.07% of the mass of the initiator, and the addition amount of the second batch of zinc-cobalt double metal cyanide complex is 30% of the total mass of the zinc-cobalt double metal cyanide complex; the second part of epoxy monomer comprises 4.37-4.98 parts of a second batch of propylene oxide and 2.42-2.77 parts of a second batch of epoxy cyclohexane in terms of mass fraction. Step (3) promotes the ring opening of propylene oxide by increasing the temperature, and tri (dimethylaminopropyl) amine preliminarily activates the reactivity of ethylene oxide, so that the branching degree is increased to about 0.52, and the decreasing amount of propylene oxide avoids the rapid increase of viscosity.

[0074] The step (4) comprises: continuously adding a third part of epoxy monomer into the microwave reactor, and reacting at 78-82 DEG C, 0.5-0.6 MPa for 1-1.2 h; wherein the third part of epoxy monomer comprises 0.96-1.1 parts of the mass fraction of the third batch of propylene oxide, 0.54-0.62 parts of the mass fraction of the third batch of epoxy cyclohexane, 10.78-12.24 parts of phenyl glycidyl ether and 4.62-5.24 parts of ethylene oxide in terms of mass fraction. Step (4) forms an aromatic ring enrichment zone by continuous grafting of phenyl glycidyl ether, and ethylene oxide is preliminarily grafted to the chain segment, so that the branching degree is increased to about 0.56, and the "PO-CHO" alternating segment accounts for about 82.1% (gel permeation chromatography (GPC) analysis), and the alicyclic density is preliminarily about 33.5%.

[0075] The step (5) comprises: continuously adding a third part of catalyst and a fourth part of epoxy monomer into the microwave reactor, and reacting at 83-87 DEG C, 0.5-0.6 MPa for 1-1.2 h; wherein the third part of catalyst comprises a third batch of zinc-cobalt double metal cyanide complex and dimethyl ethanolamine, the mass of the dimethyl ethanolamine is 0.02-0.03% of the mass of the initiator, and the addition amount of the third batch of zinc-cobalt double metal cyanide complex is 10% of the total mass of the zinc-cobalt double metal cyanide complex; the fourth part of epoxy monomer comprises 0.91-1.04 parts of a fourth batch of propylene oxide and 0.52-0.6 parts of a fourth batch of epoxy cyclohexane in terms of mass fraction. In step (5), dimethyl ethanolamine reduces the catalytic activation energy, promotes the grafting of ethylene oxide to the terminal to form primary hydroxyl, so that the branching degree is finally increased to about 0.58, the local density of aromatic ring is about 26.8% (ultraviolet spectrum analysis), and the content of primary hydroxyl is about 91.5% (acetylation method).

[0076] The step (6) comprises: degassing the product obtained in step (5) at 78-82℃ under a vacuum degree of -0.095MPa to -0.098MPa for 1-1.5h to remove unreacted propylene oxide and cyclohexene oxide, and then filtering with a 0.22μm filter membrane to remove residual catalyst, to obtain a polyether, the polyether having a hydroxyl value of 260-280mg KOH / g, a viscosity at 25℃ of 700-900mPa·s, an alicyclic ring density of about 35.2%, and an aromatic ring density of about 26.8%. The step (6) removes impurities through vacuum degassing and filtering, which can improve the purity of the polyether.

[0077] The application also provides a polyurethane composition, which comprises an A component and a polymethylpolphenyl polyisocyanate, the A component comprising a polyether and a blowing agent, the polyether being the polyether described above, or the polyether being the polyether prepared by the preparation method of the polyether described above. Since the polyurethane composition adopts all the technical solutions of all the embodiments described above, it has at least all the beneficial effects brought by the technical solutions of the embodiments described above, which will not be repeated here.

[0078] In some embodiments of the application, in the A component, the mass ratio of the polyether to the blowing agent is 100:(21.8-26.2). Exemplarily, the mass ratio of the polyether to the blowing agent can be 100:21.8, 100:22.5, 100:23.8, 100:24.6, 100:25.8, 100:26.2, etc.

[0079] Alternatively, the mass ratio of the A component to the polymethylpolphenyl polyisocyanate is 1:(1.17-1.19). Exemplarily, the mass ratio of the A component to the polymethylpolphenyl polyisocyanate is 1:1.17, 1:1.18, 1:1.19, etc.

[0080] To meet environmental protection requirements, the GWP (Global Warming Potential) of the blowing agent used in the preparation of polyurethane foam is usually reduced, but the blowing agent in the prior art has the problem of contradiction between low GWP and ultralow temperature stability (low GWP blowing agent is easy to cause low temperature shrinkage). Alternatively, the blowing agent comprises HFO-1336mzz 13 parts to 15 parts, cyclopentane 7 parts to 9 parts, isobutane (R600a for short) 1.0 part to 1.5 part and methylpentane 0.8 part to 1.0 part by mass fraction. The blowing agent of the present application can reduce the GWP of the blowing agent by using the above-mentioned HFO-1336mzz, cyclopentane, isobutane and methylpentane, so that the GWP of the blowing agent is ≤15 (calculated according to the IPCC AR6 method) to meet the environmental protection requirements, while the GWP of the existing blowing agent is ≥35. Among them, HFO-1336mzz can reduce the gas phase thermal conductivity coefficient (≤0.009 W / (m K), cyclopentane can adjust the cell size to 50 μm to 80 μm, isobutane can control the foaming pressure to 0.3 MPa to 4 MPa, and methylpentane can optimize the cell stability at ultralow temperature, thereby solving the problem of contradiction between low GWP and ultralow temperature stability existing in the prior art.

[0081] Exemplarily, the mass fraction of the HFO-1336mzz can be 13 parts, 13.5 parts, 14 parts, 14.5 parts or 15 parts, etc.; the mass fraction of the cyclopentane can be 7 parts, 7.5 parts, 8 parts, 8.5 parts or 9 parts, etc.; the mass fraction of the isobutane can be 1.0 part, 1.1 part, 1.2 part, 1.3 part, 1.4 part or 1.5 part, etc.; the mass fraction of the methylpentane can be 0.8 part, 0.85 part, 0.9 part, 0.95 part or 1.0 part, etc. Among them, when the mass fraction of the HFO-1336mzz is 14 parts, the mass fraction of the cyclopentane is 8 parts, the mass fraction of the isobutane is 1.1 parts, and the mass fraction of the methylpentane is 0.9 parts, the GWP of the blowing agent is 4.84 (the weighted GWP calculated according to the IPCC AR6 method).

[0082] In some embodiments of the present application, the A component further comprises an interfacial control agent 0.5 parts to 0.7 parts by mass, the interfacial control agent comprising one or more of polyfluorobutyl methacrylate (PFBM), hexafluorobutyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, monoalkoxy titanate (e.g., TMC-101), polyfluoroalkyl methacrylate (e.g., polydodecafluoroheptyl methacrylate), and polyethylene glycol diacrylate-butyl acrylate copolymer. Illustratively, the interfacial control agent can be 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, or 0.7 parts by mass, etc. By adding the above interfacial control agent, the cell wall thickness deviation can be reduced (≤3 μm) and the cell diameter standard deviation can be ≤5 μm (current ≥15 μm), making the cells uniform, the cells not broken at ultra-low temperature, and thus the thermal conductivity of the polyurethane foam more stable (thermal conductivity ≤25 mW / (m K) at -80°C), so that the polyurethane foam can be applied to high and low temperature (-80°C) scenarios.

[0083] Optionally, the A component further comprises a nucleating agent 0.6 parts to 0.8 parts by mass, the nucleating agent comprising one or more of FA-188, PF5050, PF5060, and PF5056 produced by 3M. Illustratively, the nucleating agent can be 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, or 0.5 parts by mass, etc.

[0084] Optionally, the A component further comprises polyethylene glycol diacrylate 0.2 parts to 0.4 parts by mass. By adding the above polyethylene glycol diacrylate as an anti-cracking agent, the anti-cracking performance of the polyurethane foam can be improved, and the cracking risk of the polyurethane foam can be reduced. Illustratively, the polyethylene glycol diacrylate can be 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, or 0.4 parts by mass, etc.

[0085] Optionally, the A component further comprises nitrile rubber powder 0.7 parts to 0.9 parts by mass, the nitrile rubber powder having a particle size of 450 nm to 550 nm. By adding the above nitrile rubber powder as a vibration resistance agent, the vibration resistance strength of the polyurethane foam can be improved. Illustratively, the nitrile rubber powder can be 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, or 0.9 parts by mass, etc.; and the nitrile rubber powder can have a particle size of 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, or 550 nm, etc.

[0086] K), cyclopentane (mass fraction of 7 parts to 9 parts) can adjust the cell size to 50 μm~80 μm, isobutane (mass fraction of 1.0 parts to 1.5 parts) can control the foaming pressure to be 0.3 MPa~0.4 MPa, methylpentane (mass fraction of 0.8 parts to 1.0 parts) can improve the ultra-low temperature cell stability; the interfacial modifier (mass fraction of 0.5 parts to 0.7 parts) is selected from polyfluorobutyl methacrylate (PFBM), hexafluorobutyl methacrylate, hexafluorobutyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, monoalkoxy titanate, polyfluoroalkyl acrylate, polyethylene glycol diacrylate-butyl acrylate copolymer, etc., which can make the cell wall thickness deviation ≤3 μm, while the cell diameter standard deviation ≤5 μm (present technology ≥15 μm); the nucleating agent (mass fraction of 0.6 parts to 0.8 parts) is selected from FA-188, PF5050, PF5060, PF5056, etc. produced by 3M company, which can promote uniform nucleation of cells; the anti-cracking agent (mass fraction of 0.2 parts to 0.4 parts) includes polyethylene glycol diacrylate, which can improve the anti-cracking performance of the foam; the butyl nitrile rubber powder with particle size of 450 nm~550 nm (mass fraction of 0.7 parts to 0.9 parts) as an anti-vibration agent, which can make the foam anti-vibration strength ≥1.2 MPa (adapted to vehicle refrigerator and other scenes); the mass ratio of multiple methyl polyphenyl polyisocyanate to component A is 1: (1.17~1.19), and the multiple methyl polyphenyl polyisocyanate can provide -NCO groups to react with the hydroxyl groups of polyether to form urea bonds, ensuring the crosslinking density of the foam.

[0087] The polyurethane foam prepared by the polyurethane composition provided by the embodiment of the present application has the advantages of the polyurethane composition provided by the embodiment of the present application.

[0088] Specifically, the shrinkage rate of the polyurethane foam is ≤0.4% at -80℃, 24h, the thin-wall filling rate is ≥99% at 15 mm, and the thermal conductivity is ≤14 mW / (m​ K), compression strength ≥ 0.23 MPa. The polyurethane foam can be suitable for super-low-temperature deep-freezing refrigeration equipment, ultra-thin refrigerators, etc.

[0089] The application also provides a preparation method of the polyurethane foam, which comprises the following steps: mixing a polyether and a foaming agent to obtain component A, wherein the polyether is the above-mentioned polyether, or the polyether is obtained by the above-mentioned preparation method of the polyether; mixing the component A and a polymethyl polyphenyl polyisocyanate, and injecting the mixture into a foaming mold to foam, thereby obtaining the polyurethane foam.

[0090] Optionally, the polymethyl polyphenyl polyisocyanate comprises one or more of polymethyl polyphenyl polyisocyanate PM-200, polymethyl polyphenyl polyisocyanate 44V20, polymethyl polyphenyl polyisocyanate MR-200, and polymethyl polyphenyl polyisocyanate M20S.

[0091] In some embodiments of the application, the mixing of the polyether and the foaming agent comprises: adding the polyether into an ultrasonic vacuum stirring kettle, heating to 50-55°C (for example, 50°C, 51°C, 52°C, 53°C, 54°C, or 55°C, etc.), adding the foaming agent and a nucleating agent, or adding the foaming agent, the nucleating agent, and an interface control agent, and performing ultrasonic vacuum stirring treatment to obtain component A; mixing the component A and the polymethyl polyphenyl polyisocyanate, and injecting the mixture into a foaming mold, and sequentially performing hot air curing treatment, low-temperature shaping treatment, and normal-temperature curing treatment to obtain the polyurethane foam. By performing ultrasonic vacuum stirring treatment, the bubbles can be broken and the molecular diffusion can be accelerated, so that the foaming agent is uniformly dispersed without stratification or with a stratification rate of ≤0.5% (the prior art ≥5%), the dispersion uniformity is improved, thereby improving the foam performance consistency, and the batch standard deviation of the foam performance is ≤3% (the prior art ≥8%).

[0092] Optionally, the ultrasonic power of the ultrasonic vacuum stirring treatment is 340-360 W, the ultrasonic frequency is 20-21 kHz, the vacuum degree is -0.092 to -0.095 MPa, and the stirring time is 38-42 min. For example, the ultrasonic power of the ultrasonic vacuum stirring treatment can be 340 W, 345 W, 350 W, 355 W, or 360 W, etc., the ultrasonic frequency can be 20 kHz, 20.5 kHz, or 21 kHz, etc., the vacuum degree can be -0.092 MPa, -0.093 MPa, -0.094 MPa, or -0.095 MPa, etc., and the stirring time can be 38 min, 39 min, 40 min, 41 min, or 42 min, etc.

[0093] Optionally, the temperature of the hot air aging treatment is 57-63℃, and the time is 2-2.2h. Illustratively, the temperature of the hot air aging treatment can be 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, or 63℃, and the time of the hot air aging treatment can be 2h, 2.1h, or 2.2h, etc.

[0094] Optionally, the temperature of the low-temperature setting treatment is -8--12℃, and the time is 1-1.2h. Illustratively, the temperature of the low-temperature setting treatment can be -8℃, -9℃, -10℃, -11℃, or -12℃, etc., and the time of the low-temperature setting treatment can be 1h, 1.1h, or 1.2h, etc.

[0095] Optionally, the temperature of the normal-temperature aging treatment is 23-28℃, and the time is 20-22h. Illustratively, the temperature of the normal-temperature aging treatment can be 23℃, 24℃, 25℃, 26℃, 27℃, or 28℃, etc., and the time of the normal-temperature aging treatment can be 20h, 20.5h, 21h, 21.5h, or 22h, etc.

[0096] It can be understood that the polyurethane foam provided by the embodiments of the present application can be applied to the following scenarios: (1) ultra-low temperature refrigeration equipment, such as -80℃ biological sample refrigerator, -60℃ commercial deep-freezing refrigerator, etc.; (2) ultra-thin energy-saving refrigerator, such as 12-15mm wall thickness of household ultra-thin refrigerator (energy consumption ≤0.25kWh / 24h); (3) environmentally friendly refrigeration equipment, such as refrigerator / cold chain box exported to the European Union, North America, and other regions with strict environmental protection regulations; (4) special refrigeration equipment, such as vehicle-mounted refrigerator (vibration resistance ≥1.2MPa), medical cold storage box (temperature fluctuation ±0.5℃), etc.

[0097] In summary, the polyurethane foam provided by the embodiments of the present application can be suitable for the preparation of the insulation layer of -80℃-40℃ ultra-low temperature refrigeration equipment (such as biological sample refrigerator, commercial deep-freezing refrigerator), 12-15mm wall thickness of ultra-thin refrigerator, etc., to meet the requirements of ultra-low temperature stability, ultra-thin filling, and ultra-low global warming potential value (GWP) of environmental protection.

[0098] The technical solutions and technical effects of the present application will be described in detail below through specific examples and comparative examples, and the following examples are only part of the examples of the present application, and do not specifically limit the present application.

[0099] Example 1 The present embodiment 1 provides a polyether and polyurethane foam.

[0100] The preparation method of the polyether includes the following steps: (101) 40 parts of sucrose (analytically pure, hydroxyl value 1200 mgKOH / g), 10 parts of glycerol (purity ≥ 99.5%), 8 parts of THEIC (industrial grade, purity ≥ 98%) and 5 parts of pentaerythritol (purity ≥ 99%) were added into a 500 mL microwave reactor, vacuumized to -0.095 MPa, replaced by nitrogen for 3 times, heated to 75°C, microwave (frequency 2.45 GHz, power 200 W) assisted stirring (rotating speed 300 rpm) for 30 min, and the initial agent hydroxyl dissociation degree was detected as 96.2% (1H-NMR monitoring 3.2-3.8 ppm peak intensity); (102) 0.015 parts of Zn-Co type DMC and 0.01 parts of DBZ were added, 6.68 parts of PO and 3.526 parts of CHO were added dropwise, and the reaction was carried out at 75°C and 0.35 MPa for 1 h, and the DB (i.e. branching degree) increased to 0.45; (103) 0.008 parts of Zn-Co type DMC and 0.038 parts of TDPA were added, 4.676 parts of PO and 2.593 parts of CHO were added dropwise, and the reaction was carried out at 80°C and 0.45 MPa for 2 h, and the DB increased to 0.52; (104) 1.027 parts of PO and 0.581 parts of CHO were added dropwise, and the reaction was continued, and the DB increased to 0.56; (105) 0.003 parts of Zn-Co type DMC and 0.016 parts of DMEA were added, 0.977 parts of PO, 0.56 parts of CHO, 11.511 parts of PGE and 4.931 parts of EO were added dropwise, and the reaction was carried out at 85°C and 0.55 MPa for 1 h, and the DB increased to 0.58; (106) The product obtained in step (105) was vacuum degassed at 80°C and -0.098 MPa for 1 h, and then filtered with a 0.22 μm filter membrane to obtain a polyether.

[0101] B. The preparation method of the polyurethane foam comprises the following steps: (201) Preparation of foaming system: 100 parts of polyether was added into an ultrasonic vacuum stirring kettle, heated to 55°C, 0.6 parts of foaming agent (HFO-1336mzz 14 parts, cyclopentane 8 parts, R600a 1.1 parts and methylpentane 0.9 parts), 0.7 parts of nucleating agent (FA-188 produced by 3M Company) and PFBM 0.6 parts were added, ultrasonic (frequency 20 kHz, power 350 W), vacuum (-0.092 MPa) and stirring (rotating speed 300 rpm) for 40 min to obtain component A; (202) Foam molding and curing: A component and PM200 (NCO 31%) are mixed in a ratio of 1:1.18 by mass, injected into a 15mm thin-walled mold by a high-pressure foaming machine (120bar, 20℃), then sequentially cured at 60℃ for 2h, shaped at -10℃ for 1h and cured at 25℃ for 21h, to obtain a polyurethane foam.

[0102] Example 2 Example 2 is basically the same as Example 1, except that: In step (101), sucrose is changed to 39 parts, glycerol is changed to 9 parts, THEIC is changed to 7 parts, and pentaerythritol is changed to 4 parts; In step (102), Zn-Co type DMC is changed to 0.014 parts, DBZ is changed to 0.009 parts, PO is changed to 6.255 parts, and CHO is changed to 3.303 parts; In step (103), Zn-Co type DMC is changed to 0.007 parts, TDPA is changed to 0.036 parts, PO is changed to 4.379 parts, CHO is changed to 2.428 parts, and the reaction is carried out at 80℃, 0.45MPa for 2h, and DB is increased to 0.52; In step (104), PO is changed to 0.962 parts, and CHO is changed to 0.544 parts; In step (105), Zn-Co type DMC is changed to 0.003 parts, DMEA is changed to 0.015 parts, PO is changed to 0.914 parts, CHO is changed to 0.525 parts, PGE is changed to 10.78 parts, and EO is changed to 4.62 parts.

[0103] Example 3 Example 3 is basically the same as Example 1, except that: In step (101), sucrose is changed to 41 parts, glycerol is changed to 11 parts, THEIC is changed to 9 parts, and pentaerythritol is changed to 6 parts; In step (102), Zn-Co type DMC is changed to 0.016 parts, DBZ is changed to 0.011 parts, PO is changed to 7.105 parts, and CHO is changed to 3.754 parts; In step (103), Zn-Co type DMC is changed to 0.008 parts, TDPA is changed to 0.041 parts, PO is changed to 4.974 parts, CHO is changed to 2.761 parts, and the reaction is carried out at 80℃, 0.45MPa for 2h, and DB is increased to 0.52; In step (104), PO is changed to 1.093 parts, and CHO is changed to 0.618 parts; In step (105), the Zn-Co type DMC was changed to 0.003 parts, DMEA was changed to 0.017 parts, PO was changed to 1.039 parts, CHO was changed to 0.597 parts, PGE was changed to 12.24 parts, and EO was changed to 5.24 parts.

[0104] Example 4 Example 4 is basically the same as Example 1, except that: In step (201), HFO-1336mzz was changed to 13 parts, cyclopentane was changed to 9 parts, and R600a was changed to 1.0 part.

[0105] Comparative Example 1 This comparative example provides a polyether and polyurethane foam.

[0106] A. The method for preparing the polyether includes the following steps: (301) According to the mass parts, 42.0 parts of sucrose, 12.0 parts of glycerol, 9.0 parts of THEIC, and 0.1 parts of deionized water were added to a 500 mL conventional reaction kettle, vacuumed to-0.090 MPa, replaced with nitrogen for 2 times, heated to 90°C, and conventionally mechanically stirred (speed 200 rpm) for 40 min, and the hydroxyl dissociation degree was ≤85% (1H-NMR monitoring 3.2 ppm~3.8 ppm peak intensity, lower than 95% of Example 1); (302) One-time addition of catalyst (tetramethyl guanidine 0.08 parts and dimethylcyclohexylamine 0.07 parts), heating to 115°C, slowly adding PO 14.471 parts, controlling the pressure to 0.5 MPa, and constant temperature reaction for 4 h; (303) The product obtained in step (302) was degassed at 100°C under-0.095 MPa vacuum for 2 h, then filtered with a 0.22 μm filter membrane to obtain the polyether.

[0107] B. The method for preparing the polyurethane foam includes the following steps: (401) Foaming system preparation: 100 parts of polyether, foaming agent (cyclopentane 10.0 parts, HFO-1233zd 8.0 parts, and R600a 1.5 parts), nucleating agent (talc, particle size 5 μm) 0.5 parts, and foam stabilizer (silicone oil L-580) 1.2 parts were added to a conventional stirred kettle, and conventionally stirred (speed 300 rpm) at 25°C for 30 min; (402) Foam forming and curing: A component and PM200 (NCO 31%) were injected into a 15 mm thin-walled mold by a high-pressure foaming machine (120 bar, 20°C) at a mass ratio of 1:1.18, then sequentially hot air cured at 60°C for 3 h and room temperature cured at 25°C for 24 h to obtain a polyurethane foam.

[0108] The polyethers and polyurethane foams of Examples 1-5 and Comparative Example 1 were subjected to performance tests, and the test results are shown in Table 1 below. The performance test items included: polyether viscosity (25℃), polyether hydroxyl value, thermal conductivity of polyurethane foam at 10℃, thermal conductivity of polyurethane foam at -80℃, vertical compressive strength of polyurethane foam, shrinkage rate of polyurethane foam (-80℃ x 24h), 15mm thin-wall filling rate, GWP of foaming system, and overall energy consumption (kWh / 24h).

[0109] The test methods for each performance are as follows: Polyether viscosity: measured according to GB / T 12008.8-2010 (25℃, rotational viscometer); Polyether hydroxyl value: measured according to GB / T 12008.3-2022; Thermal conductivity: measured according to GB / T 10294-2008 (10℃ / -80℃, hot-wire method); Compressive strength: measured according to GB / T 8813-2022 (stress at 10% deformation); Ultra-low temperature shrinkage: measured according to GB / T 8811-2019 (-80℃ x 24h, volume change rate); Thin-wall filling rate: measured by CT scanning (15mm wall thickness mold, hollow area ratio); GWP: calculated according to the IPCC AR6 method; Overall energy consumption: measured according to GB 12021.2-2015 “Limiting Value and Energy Efficiency Grade of Household Refrigerator Energy Consumption”.

[0110] Table 1

[0111] As can be seen from Table 1, compared with the polyether and polyurethane foam of Comparative Example 1, the polyether viscosity of Examples 1-5 of the present application is much lower than that of Comparative Example 1 under the condition of similar hydroxyl value; the 10℃ thermal conductivity, -80℃ thermal conductivity, -80℃ x 24h shrinkage rate, and foaming system GWP of the polyurethane foam of Examples 1-5 of the present application are lower than those of Comparative Example 1, and the vertical compressive strength and 15mm thin-wall filling rate of the polyurethane foam of Examples 1-5 of the present application are higher than those of Comparative Example 1.

[0112] The polyether, the preparation method of the polyether, the polyurethane composition, the polyurethane foam and the preparation method of the polyurethane foam provided by the embodiments of the present application are described in detail above, and specific examples are applied in the present text to set forth the principles and implementation manners of the present application, and the above embodiment descriptions are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes, and in conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A polyether, characterized in that, The raw materials of the polyether include a starter and an epoxy monomer, the starter includes sucrose 39-41 parts, glycerol 9-11 parts, tri(2-hydroxyethyl) isocyanurate 7-9 parts and pentaerythritol 4-6 parts by mass fraction, and the epoxy monomer includes propylene oxide 12.51-14.21 parts.

2. The polyether of claim 1, wherein, The epoxy monomer further includes cyclohexene oxide 6.8-7.73 parts by mass fraction.

3. The polyether of claim 2, wherein, The epoxy monomer further includes phenyl glycidyl ether 10.78-12.24 parts and oxirane 4.62-5.24 parts by mass fraction.

4. The polyether of claim 3, wherein, The raw materials of the polyether further include a catalyst, the catalyst includes zinc-cobalt double metal cyanide complex and tri(dimethylaminopropyl) amine, the mass of the zinc-cobalt double metal cyanide complex is 0.035%-0.045% of the mass of the starter, and the mass of the tri(dimethylaminopropyl) amine is 0.05%-0.07% of the mass of the starter.

5. The polyether of claim 4, wherein, The catalyst further includes dibutyl zinc and / or dimethyl ethanolamine, the mass of the dibutyl zinc is 0.012%-0.018% of the mass of the starter, and the mass of the dimethyl ethanolamine is 0.02%-0.03% of the mass of the starter. The mass of the catalyst is 0.129-0.171 parts.

6. The polyether according to any one of claims 1 to 5, wherein The polyether has a hydroxyl value of 260-280 mg KOH / g and a viscosity of 700-900 mPa·s at 25 ℃. The polyether has a cycloaliphatic density of 32%-38% and an aromatic ring density of 25%-28%, and the content of primary hydroxyl groups is ≥90%. The polyether further includes an antioxidant 0.2-0.3 parts by mass fraction.

7. A process for the preparation of a polyether, characterized in that, The method comprises the following steps: Mixing the starter and the epoxy monomer to obtain the polyether. The starter includes sucrose 39-41 parts, glycerol 9-11 parts, tri(2-hydroxyethyl) isocyanurate 7-9 parts and pentaerythritol 4-6 parts by mass fraction, and the epoxy monomer includes propylene oxide 12.51-14.21 parts.

8. The method of claim 7, wherein the polyether is prepared by the reaction of a compound of formula (I) with a compound of formula (II) in the presence of a base. The method for preparing the polyether comprises the following steps: (1) adding the starter into a reaction kettle for activation; (2) adding a first part of catalyst and a first part of epoxy monomer into the reaction kettle, reacting at a first temperature for a first time, and the first part of epoxy monomer includes a first batch of propylene oxide; (3) continuously adding a second part of catalyst and a second part of epoxy monomer into the reaction kettle, reacting at a second temperature for a second time, the second temperature is greater than the first temperature, the second part of epoxy monomer includes a second batch of propylene oxide, and the addition amount of the second batch of propylene oxide is less than that of the first batch of propylene oxide; (4) continuously adding a third part of epoxy monomer into the reaction kettle, the third part of epoxy monomer includes a third batch of propylene oxide, and reacting at the second temperature, and the addition amount of the third batch of propylene oxide is less than that of the second batch of propylene oxide. (5) continuing to add a third part of catalyst and a fourth part of epoxy monomer into the reactor, reacting for a third time at a third temperature, the third temperature being greater than the second temperature, the fourth part of epoxy monomer comprising a fourth batch of propylene oxide, the fourth batch of propylene oxide being added in an amount less than the third batch of propylene oxide; (6) removing unreacted epoxy monomer and catalyst to obtain polyether.

9. The method for preparing polyether according to claim 8, characterized in that, The first batch of propylene oxide is 6.25 parts to 7.11 parts, the second batch of propylene oxide is 4.37 parts to 4.98 parts, the third batch of propylene oxide is 0.96 parts to 1.1 parts, and the fourth batch of propylene oxide is 0.91 parts to 1.04 parts; And / or, the first part of the epoxy monomer further comprises a first batch of epoxy cyclohexane, the mass fraction of the first batch of epoxy cyclohexane being 3.3 parts to 3.76 parts; the second part of the epoxy monomer further comprises a second batch of epoxy cyclohexane, the mass fraction of the second batch of epoxy cyclohexane being 2.42 parts to 2.77 parts; the third part of the epoxy monomer further comprises a third batch of epoxy cyclohexane, the mass fraction of the third batch of epoxy cyclohexane being 0.54 parts to 0.62 parts; The fourth part of the epoxy monomer further comprises a fourth batch of epoxy cyclohexane, the mass fraction of the fourth batch of epoxy cyclohexane being 0.52 parts to 0.6 parts; And / or, the third part of the epoxy monomer further comprises phenyl glycidyl ether 10.78 parts to 12.06 parts and oxirane 4.62 parts to 5.17 parts; And / or, the first part of the catalyst comprises a first batch of zinc-cobalt double metal cyanide complex and dibutyl zinc, the first batch of zinc-cobalt double metal cyanide complex being added in an amount of 60% of the total mass of the zinc-cobalt double metal cyanide complex, the total mass of the zinc-cobalt double metal cyanide complex being 0.035% to 0.045% of the mass of the starter, and the mass of the dibutyl zinc being 0.012% to 0.018% of the mass of the starter; The second part of the catalyst comprises a second batch of zinc-cobalt double metal cyanide complex and tri(dimethylaminopropyl)amine, the mass of the tri(dimethylaminopropyl)amine being 0.05% to 0.07% of the mass of the starter, and the second batch of zinc-cobalt double metal cyanide complex being added in an amount of 30% of the total mass of the zinc-cobalt double metal cyanide complex; The third part of the catalyst comprises a third batch of zinc-cobalt double metal cyanide complex and dimethyl ethanolamine, the mass of the dimethyl ethanolamine being 0.02% to 0.03% of the mass of the starter, and the third batch of zinc-cobalt double metal cyanide complex being added in an amount of 10% of the total mass of the zinc-cobalt double metal cyanide complex; And / or, the first temperature is 73°C to 77°C, and the first time is 1h to 1.2h; And / or, the second temperature is 78°C to 82°C, and the second time is 2h to 2.2h; And / or, the third temperature is 83°C to 87°C, and the third time is 1h to 1.2h.

10. The method of claim 8, wherein the polyether is prepared by the reaction of a diol with a dihalide. The step (1) comprises: adding a starter into a microwave reactor, vacuumizing to-0.095MPa~ -0.098MPa, replacing with nitrogen for multiple times; heating to 73℃~77℃, microwave stirring and keeping for 30min~35min, the stirring speed is 300rpm~350rpm; And / or, the reaction pressure of the step (2) is 0.3MPa~0.4MPa; And / or, the reaction pressure of the step (3) is 0.4MPa~0.5MPa; And / or, the reaction pressure of the step (4) and the step (5) is 0.5MPa~0.6MPa; And / or, the step (6) comprises: degassing the product of the step (5) at 78℃~82℃ under the vacuum degree of-0.095MPa~ -0.098MPa for 1h~1.5h, then filtering, to obtain the polyether.

11. A polyurethane composition, characterized in that, The polyurethane composition comprises an A component and a polymethylpolphenyl polyisocyanate, the A component comprises a polyether and a blowing agent, the polyether is the polyether of any one of claims 1~6, or the polyether is obtained by the preparation method of the polyether of any one of claims 7~10.

12. The polyurethane composition according to claim 11, characterized in that, In the A component, the mass ratio of the polyether to the blowing agent is 100:(21.8~26.2); And / or, the mass ratio of the A component to the polymethylpolphenyl polyisocyanate is 1:(1.17~1.19); And / or, the blowing agent comprises HFO-1336mzz 13 parts~15 parts, cyclopentane 7 parts~9 parts, isobutane 1.0 part~1.5 part and methylpentane 0.8 part~1.0 part by mass fraction; And / or, the GWP of the blowing agent is ≤15; And / or, the A component further comprises an interfacial control agent 0.5 part~0.7 part by mass fraction, the interfacial control agent comprises one or more of polyfluorobutyl methacrylate, hexafluorobutyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, monoalkoxy titanate, polyfluoroalkyl acrylate and polyethylene glycol diacrylate-butyl acrylate copolymer; And / or, the A component further comprises a nucleating agent 0.6 part~0.8 part by mass fraction, the nucleating agent comprises one or more of FA-188, PF5050, PF5060 and PF5056 produced by 3M company; And / or, the A component further comprises polyethylene glycol diacrylate 0.2 part~0.4 part by mass fraction; And / or, the A component further comprises butyl nitrile rubber powder 0.7 part~0.9 part by mass fraction, the particle size of the butyl nitrile rubber powder is 450nm~550nm.

13. A polyurethane foam characterized by, The polyurethane composition of any one of claims 11~12 is prepared by foaming.

14. The polyurethane foam according to claim 13, characterized in that, The polyurethane foam has a shrinkage rate of ≤0.4% at -80℃ for 24h, a 15mm thin-wall filling rate of ≥99%, a thermal conductivity of ≤14mW / (m K) at 10℃, and a compressive strength of ≥0.23MPa.

15. A process for the preparation of a polyurethane foam, characterized in that, Comprising the following steps: Mixing the polyether with a blowing agent to obtain an A component, the polyether is the polyether of any one of claims 1~6, or the polyether is obtained by the preparation method of the polyether of any one of claims 7~10; The A component is mixed with a polymeric methyl polyphenyl polyisocyanate and injected into a foaming mold to foam to obtain a polyurethane foam.

16. The method of making a polyurethane foam according to claim 15, characterized in that, The mixing of the polyether with the blowing agent comprises: The polyether is added into an ultrasonic vacuum stirring kettle, heated to 50-55 DEG C, and the blowing agent and nucleating agent or the blowing agent, nucleating agent and interface control agent are added and treated by ultrasonic vacuum stirring to obtain the A component; The A component is mixed with a polymeric methyl polyphenyl polyisocyanate and injected into a foaming mold to foam to obtain a polyurethane foam.

17. The method of making a polyurethane foam according to claim 16, characterized in that, The ultrasonic vacuum stirring treatment has an ultrasonic power of 340-360 W, an ultrasonic frequency of 20-21 kHz, a vacuum degree of -0.092- -0.095 MPa, and a stirring time of 38-42 min; And / or, the hot air curing treatment has a temperature of 57-63 DEG C and a time of 2-2.2 h; And / or, the low-temperature setting treatment has a temperature of -8- -12 DEG C and a time of 1-1.2 h; And / or, the normal-temperature curing treatment has a temperature of 23-28 DEG C and a time of 20-22 h.

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