Recyclable and biodegradable polyurethane foam as well as preparation method and application thereof

Abstract

The invention discloses recyclable and biodegradable polyurethane foam as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: initiating a cyclic ester monomer to perform ring opening polymerization through an initiator to obtain aliphatic polycyclic ester polyol; the aliphatic polycyclic ester polyol is directly used for preparing the polyurethane foam through a chemical foaming process. The polyurethane foam is prepared by the preparation method of the polyurethane foam. The recovery method of the polyurethane foam comprises the following steps: carrying out pyrolysis recovery on the polyurethane foam; wherein the pyrolysis recovery comprises the step of adding a pyrolysis catalyst for depolymerization to obtain a pure cyclic ester monomer, and pyrolysis residues can be recovered by chemical solvent decomposition or directly reused. According to the invention, the aliphatic polycyclic ester-based polyurethane foam which is easy to recover and degradable is prepared from the polycyclic ester polyol, a repolymerizable monomer with high yield and high purity can be recovered and obtained only through simple decompression pyrolysis, and in addition, the foam can be naturally degraded into a small molecular compound which is harmless to the environment in the environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a recyclable and biodegradable polyurethane foam as well as a preparation method and application thereof. BACKGROUND

[0002] High polymer foam is a kind of three-dimensional porous material with light weight, excellent shock resistance and excellent thermal insulation performance, which has very wide application in the fields of cushion packaging of electronic appliances, precision instruments and fragile products, cold chain transportation and the like. However, the current high polymer foam is mainly prepared by foaming polyethylene, polypropylene, polystyrene and polyether polyurethane and the like, and such foam is neither easy to recycle nor biodegradable. At the same time, a chemical crosslinking network is usually constructed during foaming to improve the performance of the foam, so that the biodegradation and recycling of the foam after being discarded become more difficult, and it can only be disposed of by mechanical crushing, incineration, landfill and the like, causing serious environmental pollution and resource waste and the like.

[0003] At present, the common recycling methods of high polymer foam include physical recycling and chemical recycling. Physical recycling is to crush the high polymer foam and then compound it with other polymer materials, for example, Clodoaldo Saron et al. crushed polystyrene foam and blended it with rubber for extrusion thermal mechanical processing to produce a compatibilized and toughened PS / rubber blend (Journal of Applied Polymer Science, 2023, 140(32), e52541). However, since the commonly used high polymer foam itself belongs to a crosslinked polymer with poor processing performance, the recycling process is always accompanied by structural damage, resulting in performance degradation of the recycled material. Chemical recycling is a way of reusing the high polymer foam after controlled degradation, for example, CN113817221B and CN107955206A, which crush and dry the waste polyurethane foam, and then obtain recycled polyether polyol through alcoholysis and acidolysis. However, the methods of recycling polyol mostly have problems such as complex procedure, harsh conditions and high cost. SUMMARY

[0004] The purpose of the present application is to provide a recyclable and biodegradable polyurethane foam, a preparation method, a recycling method and an application thereof. The polyurethane foam introduces an easily degradable aliphatic polycyclic ester chain segment through cyclic ester monomers, and high yield and high purity cyclic ester monomers can be recycled by simple vacuum pyrolysis, overcoming the problems of physical recycling and chemical recycling mentioned in the background art.

[0005] The embodiments of the present application are implemented as follows:

[0006] In a first aspect, the embodiments of the present application provide a preparation method of a recyclable and biodegradable polyurethane foam, comprising:

[0007] The aliphatic poly-cyclic ester polyol is obtained by ring-opening polymerization of the cyclic ester monomer initiated by the initiator;

[0008] The aliphatic poly-cyclic ester polyol is directly used to prepare the polyurethane foam through a chemical foaming process.

[0009] In a second aspect, the embodiments of the present application provide a recyclable and biodegradable polyurethane foam, which is prepared by the preparation method of the recyclable and biodegradable polyurethane foam provided in the above embodiments. The soft segment of the recyclable and biodegradable polyurethane foam comprises an aliphatic poly-cyclic ester segment.

[0010] Optionally, the pores in the polyurethane foam are mainly spherical pores.

[0011] Optionally, the pore size distribution of the pores in the polyurethane foam ranges from 50 to 15000 microns.

[0012] In a third aspect, the embodiments of the present application provide a recycling method of the recyclable and biodegradable polyurethane foam, comprising: pyrolysis recycling of the polyurethane foam;

[0013] The pyrolysis recycling comprises: adding the prepared foam, adding a pyrolysis catalyst, and depolymerizing at 10 to 2000 Pa and 60 to 300 DEG C for 0.1 to 72 hours to obtain the cyclic ester monomer.

[0014] Optionally, the vacuum degree is 50 to 150 Pa during the pyrolysis recycling.

[0015] Optionally, the temperature is 150 to 250 DEG C during the pyrolysis recycling.

[0016] Optionally, the depolymerization time is 1 to 8 hours during the pyrolysis recycling.

[0017] In a fourth aspect, the embodiments of the present application provide an application of the recyclable and biodegradable polyurethane foam provided in the above embodiments. The recyclable and biodegradable polyurethane foam is applied to the manufacturing of cushion packaging, marine engineering, shipbuilding industry, medical and health materials, building insulation materials, vehicle interior materials, or furniture materials.

[0018] Optionally, the cushion packaging is used for packaging of fragile products, electronic appliances, precision instruments, or food preservation.

[0019] The recyclable and biodegradable polyurethane foam, the preparation method, the recycling method, and the application thereof provided in the embodiments of the present application have at least the following beneficial effects:

[0020] (1) The aliphatic polycyclic ester segment introduced in the polyurethane foam provides more hydrogen bond sites due to its rich ester bond energy, and the network of small crystal regions formed by the limited crystallization of the soft segment is beneficial to the improvement of the mechanical properties of the foam, and is beneficial to the regulation of the compressive strength, resilience and other mechanical properties of the foam material.

[0021] (2) The hydrolytic degradation of the ester bond of the aliphatic polycyclic ester segment introduced in the polyurethane foam can realize the decomposition of the foam material in the natural environment, avoiding its long-term retention in the environment.

[0022] (3) The aliphatic polycyclic ester segment introduced in the polyurethane foam can be cyclized and depolymerized by simple vacuum pyrolysis to obtain high yield and high purity of cyclic ester monomers; at the same time, the pyrolysis residue can be recycled into polyols, polyamines and the like by chemical solventysis, or can be directly upgraded to ionic adhesives by forming ionic interaction between the urethane bond in the pyrolysis residue and the sulfonic acid group, which is beneficial to the closed-loop recycling and full recycling of the foam material.

[0023] The recycling method is simple, and the recycled material has high yield and high purity, which overcomes the problem of performance degradation of the recycled material caused by physical recycling mentioned in the above background technology, and overcomes the problems of complex recycling process, harsh conditions and high cost of chemical recycling mentioned in the above background technology.

[0024] (4) In some methods for preparing foam materials, a polyurethane matrix is first formed by crosslinking for a long time, and then physical and mechanical foaming treatment such as solvent dissolution and freeze-drying is performed to obtain a porous material. In the preparation method of the present application, the polyurethane foam is directly prepared by chemical foaming process using aliphatic polycyclic ester polyol, and compared with the preparation method of first crosslinking to form a polyurethane matrix and then physical and mechanical foaming treatment, at least the following advantages are obtained:

[0025] Direct foaming usually only needs to stir and mix for a few minutes (when the polyurethane matrix is first formed by crosslinking, usually several hours are needed), the reaction time required is relatively short, and the crosslinking degree is relatively low, which is more conducive to degradation and recycling.

[0026] The pores formed by direct foaming are mainly regular spherical pores (when the polyurethane matrix is first formed by crosslinking and then foaming treatment, the pores formed are usually irregular flat pores and long strip-shaped pores in size and shape), which have more balanced mechanical properties.

[0027] The pore size of the holes formed by direct foaming is mainly distributed above 200 microns, wherein the pore size of the large holes can reach 1000 microns, 1200 microns or even 1500 microns, the foam material has larger holes (when cross-linking is formed first and then foaming treatment is performed, small holes of tens of microns are usually formed), and when natural degradation is performed, the foam material can be more in contact with the environment medium, and when pyrolysis treatment is performed, the foam material can be better in contact with the pyrolysis catalyst and the like, which is beneficial to degradation and pyrolysis recycling. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 The physical map, scanning electron microscope photo and pore size distribution graph of the PPDO-based polyurethane foam prepared in the embodiment 12 of the present application;

[0030] Figure 2 The physical map, scanning electron microscope photo and pore size distribution graph of the PCL-based polyurethane foam prepared in the embodiment 35 of the present application;

[0031] Figure 3 The X-ray diffraction spectrum of the polyurethane foam and PPDO prepared in the embodiments 6, 8, 12 and 15 of the present application;

[0032] Figure 4 The first heating DSC curve of the polyurethane foam prepared in the embodiments 6, 7, 8, 9, 12, 13, 15 and 16 of the present application;

[0033] Figure 5 The cyclic compression stress-strain curve of the PPDO-based polyurethane foam prepared in the embodiment 12 of the present application;

[0034] Figure 6 The compression strength and compression modulus column chart of the polyurethane foam prepared in the embodiments 6, 7, 8, 9, 12, 13, 14, 15, 16 and 29 of the present application;

[0035] Figure 7 The rebound rate column chart of the polyurethane foam prepared in the embodiments 6, 7, 8, 9, 12, 13, 14, 15, 16 and 29 of the present application;

[0036] Figure 8 The nuclear magnetic hydrogen spectrum of PDO obtained by pyrolysis recycling of the polyurethane foam in the embodiment 9 and the embodiment 15 of the present application;

[0037] Figure 9 Pictures of PPDO-based polyurethane foams prepared in Examples 6, 8, 12 of the present application and commercial polyurethane foams before degradation;

[0038] Figure 10 Pictures of PPDO-based polyurethane foams prepared in Examples 6, 8, 12 of the present application and commercial polyurethane foams after 7 days of degradation;

[0039] Figure 11 Adhesion strength of the ionic adhesive formed by the interaction of AMPS and pyrolysis residues in Example 2 to different substrates. DETAILED DESCRIPTION

[0040] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below. If specific conditions are not specified in the embodiments, conventional conditions or manufacturer recommended conditions are used. If the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased on the market.

[0041] It should be noted that in the present application, “and / or”, such as “feature 1 and / or feature 2”, means that it can be “feature 1” alone, “feature 2” alone, or “feature 1” plus “feature 2”, and the three cases.

[0042] In addition, in the description of the present application, unless otherwise specified, the meaning of “multiple” in “one or more” is two or more, and the understanding of other similar descriptions is referred to the description here; the range of “numerical value a~numerical value b” includes both end values “a” and “b”, and “measurement unit” in “numerical value a~numerical value b+measurement unit” represents the “measurement unit” of both “numerical value a” and “numerical value b”.

[0043] The technical solutions of the embodiments of the present application will be described below by way of example.

[0044] In a first aspect, the embodiments of the present application provide a preparation method of a recyclable and biodegradable polyurethane foam, comprising: initiating ring-opening polymerization of a cyclic ester monomer by an initiator to obtain an aliphatic poly-cyclic ester polyol; and directly preparing a polyurethane foam by a chemical foaming process using the aliphatic poly-cyclic ester polyol.

[0045] Regarding the ring-opening polymerization step:

[0046] In embodiments of the present application, the kind of cyclic ester monomer is not limited, and preferably a cyclic ester monomer with good degradation performance. In some embodiments, the cyclic ester monomer includes one or more of p-dioxanone (abbreviated as PDO in the embodiments), ε-caprolactone (abbreviated as ε-CL in the embodiments), γ-butyrolactone, β-butyrolactone, lactide, glycolide. Among them, the lactide can be L-lactide (abbreviated as LLA in the embodiments) or D-lactide (abbreviated as DLA in the embodiments).

[0047] As an example, the cyclic ester monomer is p-dioxanone. Research has found that when p-dioxanone is used as the cyclic ester monomer, the polyurethane foam prepared has better recycling performance, which is conducive to achieving higher cyclic ester monomer recovery rate and recovery purity during pyrolysis recycling.

[0048] Research has found that by adjusting the molar mass of the aliphatic poly cyclic ester polyol, the crystallization of the soft segment of the polyurethane foam can be effectively adjusted, thereby better achieving the adjustment of the mechanical properties of the polyurethane foam. It can be conveniently prepared to obtain materials with high compressive strength and high resilience, materials with high compressive strength and low thermal conductivity, materials with high resilience and low density performance, so that it has great potential application in the fields of cushion packaging, cold chain transportation materials and furniture material manufacturing.

[0049] Based on this, as an example, the molar mass of the aliphatic poly cyclic ester polyol is 400-12000 kg / mol, for example but not limited to any one of 400 kg / mol, 1000 kg / mol, 2000 kg / mol, 3000 kg / mol, 4000 kg / mol, 5000 kg / mol, 6000 kg / mol, 7000 kg / mol, 8000 kg / mol, 9000 kg / mol, 10000 kg / mol, 11000 kg / mol, 12000 kg / mol or a range value between any two of them.

[0050] In embodiments of the present application, the kind of initiator is not limited, for example but not limited to polyols, polyamines, etc. When polyamines are used as initiators, urea-based structures are formed. Compared with polyamines, the structure after polymerization of polyols is easier to pyrolysis recycle, and preferably the initiator is a polyol.

[0051] As an example, the initiator includes one or more of 1,4-butanediol, 1,6-hexanediol, glycerol, pentaerythritol, polylactic acid (PLA) polyol and its copolymer polyol, polycaprolactone (PCL) polyol and its copolymer polyol, polyglycolic acid (PGA) polyol and its copolymer polyol, polyethylene glycol (PEG) polyol and its copolymer polyol, poly-p-dioxanone (PPDO) polyol and its copolymer polyol.

[0052] Regarding the foaming step:

[0053] It should be noted that during the foaming process, the aliphatic polycyclic ester polyol is only one of the raw materials, and other raw materials can be added as needed in addition to the aliphatic polycyclic ester polyol. In addition, the preparation of polyurethane foam directly by a chemical foaming process refers to directly obtaining a polyurethane foam with a three-dimensional porous structure during the foaming process, rather than first forming a polyurethane matrix and then dissolving the solvent to obtain a polyurethane foam with a three-dimensional porous structure.

[0054] In the embodiments of the present application, the chemical foaming method is not limited, for example but not limited to isocyanate foaming method, cyclic carbonate foaming method, etc.

[0055] In some embodiments, the chemical foaming process adopts the isocyanate foaming method, which includes: reacting 100 parts by mass of aliphatic polycyclic ester polyol, 0-10 parts by mass of foam crosslinking agent, 0.1-10 parts by mass of silicone oil, 0.1-8 parts by mass of organic metal compound catalyst, 0.1-8 parts by mass of organic base catalyst, and 10-100 parts by mass of diisocyanate at 40-220°C under mechanical stirring at 200-15000 rpm for 5-300 s to form a prepolymer with a viscosity of 200-20000 mPa·s; then adding 0.3-10 parts by mass of water and stirring under mechanical stirring at 200-15000 rpm for 5-300 s; then immediately pouring into a mold with a temperature of room temperature-150°C and curing at room temperature-150°C for 1-48 h.

[0056] In some embodiments, the chemical foaming process adopts the cyclic carbonate foaming method, which includes: reacting 100 parts by mass of aliphatic polycyclic ester polyol, 0-10 parts by mass of foam crosslinking agent, 0.1-10 parts by mass of silicone oil, 0.1-8 parts by mass of inorganic base catalyst, and 10-120 parts by mass of multifunctional five-membered ring carbonate at 40-220°C for 5-180 min; then adding 0.1-100 parts by mass of water or mercaptan and reacting under mechanical stirring at 200-15000 rpm for 1-30 min; then immediately pouring into a mold with a temperature of room temperature-150°C and curing at room temperature-150°C for 1-48 h.

[0057] Wherein, the multifunctional five-membered ring carbonate is, for example, a trifunctional five-membered ring carbonate; full name 1,3-dioxy-2-ketone, 4,4'-[[2-ethyl-2-[[(2-oxo-1,3-dioxy-4yl)methoxy]methyl]-1,3-propanediyl]bis(oxy methylene)]; abbreviated as TMTPC.

[0058] During the foaming process, by regulating the amount of foam crosslinking agent, the mechanical properties of the polyurethane foam can be effectively adjusted, for example, as the amount of foam crosslinking agent increases, the apparent density, gel content and compressive strength of the polyurethane foam increase.

[0059] As an example, the amount of foam crosslinking agent is, for example but not limited to, any one of 0 parts by mass, 0.1 parts by mass, 1 part by mass, 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, or a range value between any two of them, based on 100 parts by mass of the aliphatic polycyclic ester polyol.

[0060] In the present application, the types of raw materials in the chemical foaming process are not limited and can be routinely selected as needed.

[0061] In some embodiments, the foam crosslinking agent is a polyol; optionally, the foam crosslinking agent includes one or more of glycerol, pentaerythritol, PLA polyol and its copolymer polyol, PCL polyol and its copolymer polyol, PGA polyol and its copolymer polyol, PEG polyol and its copolymer polyol, and PPDO polyol and its copolymer polyol.

[0062] In some embodiments, the organometallic compound catalyst includes one or more of dibutyltin dilaurate, di-n-octyltin dilaurate, stannous octoate, dibutyltin diacetate, dibutyltin mercaptide, bismuth octoate, tributyl bismuth, and dibutyltin dilaurate.

[0063] In some embodiments, the organic base catalyst includes one or more of 1,8-diazabicycloundec-7-ene, triethylamine, triethanolamine, ethylenediamine, trimethyl aniline, triethylene diamine, and tetramethyl butanediamine. The inorganic base catalyst includes one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate.

[0064] In some embodiments, the diisocyanate includes one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and L-lysine diisocyanate.

[0065] In some embodiments, the mercaptan includes one or more of methyl mercaptan, ethyl mercaptan, 1-propanethiol, n-butyl mercaptan, isobutyl mercaptan, phenyl mercaptan, 2-mercaptoethanol, mercaptoacetic acid, 2-mercaptobenzothiazole, mercaptopropionic acid, mercaptoethylamine, and thioglycerol.

[0066] In a second aspect, the embodiments of the present application provide a recyclable and biodegradable polyurethane foam, which is prepared by the preparation method of the recyclable and biodegradable polyurethane foam provided in the above embodiments. The soft segment of the recyclable and biodegradable polyurethane foam comprises an aliphatic polycyclic ester segment.

[0067] Optionally, the pores in the recyclable and biodegradable polyurethane foam are mainly spherical pores. It can be understood that the pores are mainly spherical pores, which means that more than half of the pores are spherical pores. In addition, it should be noted that the spherical pores do not require standard spherical shapes, but can also be spheroid shapes. Adjacent spherical pores can be spaced or connected.

[0068] Optionally, the pore diameters of the pores in the recyclable and biodegradable polyurethane foam are mainly distributed above 200 μm. It can be understood that the pore diameters are mainly distributed above 200 μm, which means that more than half of the pores have a pore diameter above 200 μm. Optionally, the pore diameters of the pores in the recyclable and biodegradable polyurethane foam are distributed in a range of 50-15000 μm. As an example, the pore diameters are mainly distributed in a range of 200-1500 μm, 200-1200 μm, or 200-1000 μm.

[0069] In a third aspect, the embodiments of the present application provide a recycling method of the recyclable and biodegradable polyurethane foam, which comprises pyrolysis recycling of the recyclable and biodegradable polyurethane foam. The pyrolysis recycling comprises adding an equivalent of the prepared foam, adding a pyrolysis catalyst, and depolymerizing at 10-2000 Pa and 60-300 ℃ for 0.1-72 h to obtain a cyclic ester monomer.

[0070] Optionally, in the pyrolysis recycling, the vacuum degree is 50-150 Pa, for example, but not limited to, any one of 50 Pa, 60 Pa, 70 Pa, 80 Pa, 90 Pa, 100 Pa, 110 Pa, 120 Pa, 130 Pa, 140 Pa, and 150 Pa, or a range value between any two of them.

[0071] Optionally, in the pyrolysis recycling, the temperature is 150-250 ℃, for example, but not limited to, any one of 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, and 250 ℃, or a range value between any two of them.

[0072] When the cyclic ester monomer is PDO, the temperature in the pyrolysis recycling is 150-200 ℃. When the cyclic ester monomer is ε-CL or LLA, the temperature in the pyrolysis recycling is 200-250 ℃.

[0073] Optionally, the depolymerization time is 1-8h, for example but not limited to any one of 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h or a range value between any two of them.

[0074] When the cyclic ester monomer is PDO, the depolymerization time is optionally 1-3h, further 1.5-2h; when the cyclic ester monomer is ε-CL or LLA, the depolymerization time is optionally 5-8h, further 5-7h.

[0075] In some embodiments, the pyrolysis catalyst comprises one or more of organometallic, inorganic non-metallic, organic acid, inorganic acid, organic base, inorganic base, organic salt, inorganic salt, ionic liquid catalyst; optionally, the pyrolysis catalyst comprises one or more of tin chloride, stannous octoate, dibutyltin dilaurate, zinc sulfate, zinc nitrate, zinc acetate, zinc bromide, sodium methoxide, potassium methoxide, sodium hydroxide, potassium hydroxide, zinc acetate, zinc oxide, titanate, antimony compound, sulfuric acid, hydrochloric acid, phosphoric acid, phosphate, oxalic acid, citric acid, p-toluenesulfonic acid, p-toluene sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid salt, glycine-tin chloride, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, tetrabutylammonium bromide, tetrabutylammonium chloride, tetramethylammonium chloride, tributylmethylphosphonium chloride, tributylmethylphosphonium bromide, amino imidazole ionic liquid, amino-functionalized quaternary ammonium salt, choline chloride-urea, choline chloride-ethylene glycol.

[0076] It is found that when the pyrolysis catalyst is an organometallic catalyst, the amount of pyrolysis catalyst used is small, and when the cyclic ester monomer is recovered, a high recovery rate and recovery purity can be achieved. In some embodiments, the pyrolysis catalyst is an organometallic catalyst, and the mass ratio of the recycled and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(0.1-10), for example but not limited to any one of 100:0.1, 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10 or a range value between any two of them.

[0077] Optionally, the organometallic catalyst is stannous octoate, and the cyclic ester monomer is p-dioxanone; it is found that based on this combination, the pyrolysis time is shorter; the recovery rate of the cyclic ester monomer is easy to reach more than 90%, and in some conditions can be as high as 99%; the purity of the recovered cyclic ester monomer is basically more than 90%, and is easy to reach 98% or even 99%.

[0078] Further, the mass ratio of the recyclable and biodegradable polyurethane foam and the pyrolysis catalyst is 100:(1-5), which can achieve a higher recovery rate and recovery purity.

[0079] Further, the mass ratio of the recyclable and biodegradable polyurethane foam and the pyrolysis catalyst is 100:(2-3), which can achieve a higher recovery rate while avoiding excessive pyrolysis catalyst affecting the purity of the recycled cyclic ester monomer, and is conducive to obtaining a cyclic ester monomer with higher purity.

[0080] It is found that when the pyrolysis catalyst is an organic acid catalyst / ionic liquid catalyst, soaking the polyurethane foam with the organic acid catalyst / ionic liquid catalyst is conducive to better pyrolysis recovery. In some embodiments, the pyrolysis catalyst is an organic acid catalyst or an ionic liquid, and the mass ratio of the polyurethane foam and the pyrolysis catalyst is 100:(10-100), such as but not limited to any one of 100:10, 100:20, 100:30, 100:40, 100:50, 100:60, 100:70, 100:80, 100:90, 100:100 or a range value between any two of them.

[0081] Optionally, the organic acid catalyst is 2-acrylamide-2-methylpropane sulfonic acid (abbreviated as AMPS in the examples), and the mass ratio of the polyurethane foam and the pyrolysis catalyst is 100:(30-100); it is found that when the organic acid catalyst is AMPS, a higher recovery rate and recovery purity can be achieved.

[0082] Optionally, the ionic liquid catalyst is glycine-tin chloride (abbreviated as [Gly] - [SnCl2] + ), the cyclic ester monomer is ε-caprolactone or L-lactide, and the mass ratio of the polyurethane foam and the pyrolysis catalyst is 100:(10-15); it is found that when the cyclic ester monomer is ε-caprolactone or L-lactide, the ionic liquid exhibits good catalytic performance, and compared with the organometallic catalyst, the recovery rate and recovery purity can reach or even exceed the effect of the organometallic catalyst under the condition of appropriately prolonging the depolymerization time.

[0083] It should be noted that in the examples of the present application, there is still pyrolysis residue after pyrolysis recovery, which can be disposed of or recycled as needed.

[0084] In some embodiments, the recycling method further comprises: after pyrolysis recycling, subjecting the pyrolysis residue to chemical solvolysis recycling, or directly upgrading the pyrolysis residue to an ionic adhesive by ionization formed in the pyrolysis residue, such as an amide bond and a sulfonic acid group; the chemical solvolysis recycling comprises one or more of alcoholysis, acidolysis, hydrolysis, ammonolysis, and ionic liquid catalytic depolymerization.

[0085] Optionally, the recycling product of the chemical solvolysis recycling comprises one or more of a polyol and a polyamine.

[0086] In a fourth aspect, the embodiments of the present application provide an application of the recyclable and biodegradable polyurethane foam provided by the above-mentioned embodiments. The polyurethane foam is applied to the manufacturing of cushion packaging, marine engineering, shipbuilding industry, medical and health materials, building insulation materials, vehicle interior materials, or furniture materials. Optionally, the cushion packaging is used for packaging of fragile products, electronic appliances, precision instruments, or food preservation.

[0087] As an example, the material with high compressive strength and high resilience is applied to cushion packaging, and the material with high resilience rate and low density performance is applied to the field of furniture material manufacturing.

[0088] Optionally, the high compressive strength material satisfies the following condition: when the compressive strain is 80% of the initial height, the compressive strength is ≥2000 KPa.

[0089] Optionally, the high resilience rate material satisfies the following condition: when the compressive strain is 50% of the initial height, the resilience rate is ≥90%.

[0090] The features and performances of the present application are further described in detail below in combination with embodiments.

[0091] I. Experimental conditions of each embodiment are as follows:

[0092] It should be noted that, unless otherwise specified, in the following embodiments, the amount of the material is in parts by mass; the preparation of the aliphatic polycycloester polyol and the recycling of the pyrolysis residue refer to Embodiments 1 and 2, which will not be described in detail hereinafter.

[0093] Embodiment 1

[0094] Preparation of poly-p-dioxanone (PPDO) polyol: 1,4-butanediol ring-opening PDO is used to prepare a PPDO diol with a molar mass of 500 kg / mol. The specific operation steps are as follows: 1) the PDO monomer and 1,4-butanediol are separately subjected to vacuum distillation to remove moisture, 2) the molar mass of 500 kg / mol is designed for the feeding and a molar fraction of 1 / 10000 of stannous octoate is added, 3) the reaction is carried out at 80℃ for 36 hours.

[0095] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 1 part, stannous octoate 0.5 parts, triethanolamine 0.5 parts, hexamethylene diisocyanate 15 parts, under the condition of 100℃ and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 3500 mPa·s, then add 2 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 70℃, solidify at 70℃ for 1h, after demolding, further solidify at room temperature for 12h, to obtain polyurethane foam.

[0096] Pyrolysis recovery of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of 85 Pa vacuum degree, 160℃ and without adding pyrolysis catalyst, depolymerization for 2h, pyrolysis to obtain 18% PDO monomer, with purity of 99%.

[0097] Recovery of pyrolysis residue: 100 parts of pyrolysis residue was mixed with 300 parts of 1,4-butanediol and 5 parts of triethanolamine, and reacted at 160℃ for 7h, to obtain alcoholysis product of pyrolysis residue.

[0098] Example 2

[0099] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, to prepare PPDO diol with molar mass of 500 kg / mol.

[0100] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 2 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, hexamethylene diisocyanate 40 parts, under the condition of 120℃ and 2000 rpm mechanical stirring, reaction for 30s, to form a prepolymer with viscosity of 4500 mPa·s, then add 4 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 70℃, solidify at 70℃ for 1h, after demolding, further solidify at room temperature for 12h, to obtain polyurethane foam.

[0101] Pyrolysis recovery of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of 85 Pa vacuum degree, 160℃ and adding 50 parts of 2-acrylamide-2-methylpropanesulfonic acid (AMPS organic acid catalyst), depolymerization for 1.5h, pyrolysis to obtain 88% PDO monomer, with purity of 96%.

[0102] Recovery of pyrolysis residue: the sulfonic acid groups in AMPS have strong ionic interaction with the urethane groups, urea groups and biuret structures in the pyrolysis residue, and the pyrolysis residue itself has strong adhesion without further treatment and can be used as an ionic adhesive.

[0103] Example 3

[0104] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, PPDO diol with a molar mass of 1500 kg / mol is prepared.

[0105] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts, under the condition of 120℃ and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with a viscosity of 3000 mPa·s, then add 5 parts of deionized water and stir for 15s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 100℃, solidify at 100℃ for 2h, after demolding, further solidify at room temperature for 36h, to obtain polyurethane foam.

[0106] Pyrolysis recovery of PDO from polyurethane foam: 100 parts of prepared polyurethane foam is subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160℃ and adding 100 parts of AMPS, depolymerization for 1.5h, pyrolysis to obtain 93% PDO monomer, with a purity of 96%.

[0107] Example 4

[0108] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, PPDO diol with a molar mass of 1500 kg / mol is prepared.

[0109] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts, under the condition of 120℃ and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with a viscosity of 3000 mPa·s, then add 5 parts of deionized water and stir for 15s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 100℃, solidify at 100℃ for 2h, after demolding, further solidify at room temperature for 36h, to obtain polyurethane foam.

[0110] Pyrolysis recovery of PDO from polyurethane foam: 100 parts of prepared polyurethane foam is subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160℃ and adding 100 parts of AMPS, depolymerization for 1.5h, pyrolysis to obtain 93% PDO monomer, with a purity of 96%.

[0111] Example 5

[0112] Preparation of PPDO polyol: PPDO diol with a molar mass of 2000 kg / mol was prepared using 1,4-butanediol ring-opening PDO.

[0113] Preparation of polyurethane foam using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts were reacted for 60 s under the condition of 100 °C and 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 2000 mPa-s, then 5 parts of deionized water was added and stirred for 10 s under the condition of 2000 rpm mechanical stirring, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, after demolding further cured at room temperature for 24 h to obtain a polyurethane foam.

[0114] Pyrolysis of polyurethane foam to recover PDO: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, depolymerized for 1 h under the condition of 100 Pa vacuum degree, 160 °C and the addition of 1 part of stannous octoate, and pyrolysis to obtain 64% of PDO monomer with a purity of 99%.

[0115] Example 6

[0116] Preparation of PPDO polyol: PPDO diol with a molar mass of 2000 kg / mol was prepared using 1,4-butanediol ring-opening PDO.

[0117] Preparation of polyurethane foam using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts were reacted for 60 s under the condition of 100 °C and 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 2000 mPa-s, then 5 parts of deionized water was added and stirred for 10 s under the condition of 2000 rpm mechanical stirring, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, after demolding further cured at room temperature for 24 h to obtain a polyurethane foam.

[0118] Pyrolysis of polyurethane foam to recover PDO: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, depolymerized for 1 h under the condition of 100 Pa vacuum degree, 160 °C and the addition of 1 part of stannous octoate, and pyrolysis to obtain 64% of PDO monomer with a purity of 99%.

[0119] Example 7

[0120] Preparation of PPDO polyol: PPDO diol with a molar mass of 2000 kg / mol was prepared using 1,4-butanediol ring-opening PDO.

[0121] Preparation of polyurethane foam using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 45 parts were reacted for 60 s under the condition of 100 °C and 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 3000 mPa-s, then 5 parts of deionized water was added and stirred for 10 s under the condition of 2000 rpm mechanical stirring, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, after demolding, further cured at room temperature for 24 h to obtain a polyurethane foam.

[0122] Pyrolysis of polyurethane foam to recover PDO: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, and PDO monomer was pyrolyzed by depolymerization at 200 °C for 1 h under the condition of 100 Pa vacuum and the addition of 1 part of stannous octoate, and 81% of PDO monomer was obtained with a purity of 99%.

[0123] Example 8

[0124] Preparation of PPDO polyol: PPDO diol with a molar mass of 3500 kg / mol was prepared using 1,4-butanediol ring-opening PDO.

[0125] Preparation of polyurethane foam using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts were reacted for 60 s under the condition of 100 °C and 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 3500 mPa-s, then 5 parts of deionized water was added and stirred for 10 s under the condition of 2000 rpm mechanical stirring, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, after demolding, further cured at room temperature for 24 h to obtain a polyurethane foam.

[0126] Pyrolysis of polyurethane foam to recover PDO: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, and PDO monomer was pyrolyzed by depolymerization at 160 °C for 1.5 h under the condition of 100 Pa vacuum and the addition of 2 parts of stannous octoate, and 92% of PDO monomer was obtained with a purity of 99%.

[0127] Example 9

[0128] Preparation of PPDO polyol: PPDO diol with a molar mass of 3500 kg / mol was prepared using 1,4-butanediol ring-opening PDO.

[0129] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 45 parts, under the condition of 100 °C and 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 5000 mPa·s, then add 5 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain polyurethane foam.

[0130] Pyrolysis of polyurethane foam to recover PDO: 100 parts of prepared polyurethane foam was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160 °C and 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 95% PDO monomer, with a purity of 99%.

[0131] Example 10

[0132] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, to prepare PPDO diol with a molar mass of 3500 kg / mol.

[0133] Preparation of polyurethane foam, using cyclic carbonate foaming method: PPDO polyol 100 parts, glycerol 3 parts, silicone oil 5 parts, KOH 5 parts, TMTPC 40 parts, under the condition of 100 °C and 5000 rpm mechanical stirring, reaction for 20 min, to form a prepolymer with a viscosity of 4000 mPa·s, then add 25 parts of ethyl mercaptan and stir for 10 min under the condition of 5000 rpm mechanical stirring, immediately pour into a mold with a temperature of 120 °C, solidify at 120 °C for 4 h, after demolding, further solidify at room temperature for 24 h, to obtain polyurethane foam.

[0134] Pyrolysis of polyurethane foam to recover PDO: 100 parts of prepared polyurethane foam was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160 °C and 5 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 99% PDO monomer, with a purity of 92%.

[0135] Example 11

[0136] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, to prepare PPDO diol with a molar mass of 3500 kg / mol.

[0137] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 1 part, triethanolamine 1 part, diisocyanate 40 parts, under the condition of 100°C, 2500 rpm mechanical stirring, reaction for 60s, to form a prepolymer with a viscosity of 4500 mPa-s, then add 5 parts of deionized water and stir for 10s under the condition of 2500 rpm mechanical stirring, immediately pour into a mold with a temperature of 80°C, solidify for 2h at 80°C, after demolding, further solidify for 24h at room temperature, to obtain polyurethane foam.

[0138] Example 12

[0139] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, to prepare PPDO diol with a molar mass of 5000 kg / mol.

[0140] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 1 part, triethanolamine 1 part, diisocyanate 40 parts, under the condition of 100°C, 2500 rpm mechanical stirring, reaction for 60s, to form a prepolymer with a viscosity of 4500 mPa-s, then add 5 parts of deionized water and stir for 10s under the condition of 2500 rpm mechanical stirring, immediately pour into a mold with a temperature of 80°C, solidify for 2h at 80°C, after demolding, further solidify for 24h at room temperature, to obtain polyurethane foam.

[0141] Pyrolysis recovery of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 200°C and adding 2 parts of stannous octoate, depolymerization for 1.5h, pyrolysis to obtain 96% PDO monomer, with a purity of 99%.

[0142] Example 13

[0143] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, to prepare PPDO diol with a molar mass of 5000 kg / mol.

[0144] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 1 part, triethanolamine 1 part, diisocyanate 40 parts, under the condition of 100°C, 2500 rpm mechanical stirring, reaction for 60s, to form a prepolymer with a viscosity of 4500 mPa-s, then add 5 parts of deionized water and stir for 10s under the condition of 2500 rpm mechanical stirring, immediately pour into a mold with a temperature of 80°C, solidify for 2h at 80°C, after demolding, further solidify for 24h at room temperature, to obtain polyurethane foam.

[0145] Pyrolysis of polyurethane foam to recycle PDO: 100 parts of polyurethane foam was subjected to fragmentation, under the condition of 100 Pa vacuum, 200 °C and 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 97% PDO monomer, purity of 99%.

[0146] Example 14

[0147] Preparation of PPDO polyol: 1,4-butanediol ring-opening PDO was used to prepare PPDO diol with a molar mass of 7800 kg / mol.

[0148] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 0 parts, silicone oil 5 parts, stannous octoate 2 parts, triethanolamine 2 parts, diisocyanate 35 parts, under the condition of 100 °C, 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 3200 mPa-s, then add 5 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain polyurethane foam.

[0149] Example 15

[0150] Preparation of PPDO polyol: 1,4-butanediol ring-opening PDO was used to prepare PPDO diol with a molar mass of 7800 kg / mol.

[0151] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 1 part, triethanolamine 1 part, diisocyanate 40 parts, under the condition of 100 °C, 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 10000 mPa-s, then add 5 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain polyurethane foam.

[0152] Pyrolysis of polyurethane foam to recycle PDO: 100 parts of polyurethane foam was subjected to fragmentation, under the condition of 100 Pa vacuum, 180 °C and 50 parts of AMPS, depolymerization for 1.5 h, pyrolysis to obtain 93% PDO monomer, purity of 92%.

[0153] Example 16

[0154] Preparation of PPDO polyol: 1,4-butanediol ring-opening PDO was used to prepare PPDO diol with a molar mass of 7800 kg / mol.

[0155] Preparation of polyurethane foam, using isocyanate blowing method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 45 parts, under 100 °C, 2000 rpm mechanical stirring conditions, reaction for 60 s, to form a prepolymer with a viscosity of 15000 mPa-s, then add 5 parts of deionized water and stir for 10 s under 2000 rpm mechanical stirring conditions, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0156] Pyrolytic recovery of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, depolymerized at 180 °C for 1.5 h under a vacuum of 100 Pa with the addition of 100 parts of AMPS, and pyrolyzed to obtain 97% PDO monomer with a purity of 90%.

[0157] Example 17

[0158] Preparation of PPDO polyol: using 1,4-butanediol ring-opening PDO, PPDO diol with a molar mass of 8500 kg / mol was prepared.

[0159] Preparation of polyurethane foam, using isocyanate blowing method: PPDO polyol 100 parts, glycerol 0 parts, silicone oil 3 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts, under 100 °C, 2000 rpm mechanical stirring conditions, reaction for 60 s, to form a prepolymer with a viscosity of 4000 mPa-s, then add 3 parts of deionized water and stir for 10 s under 2000 rpm mechanical stirring conditions, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0160] Example 18

[0161] Preparation of PPDO polyol: using glycerol ring-opening PDO, PPDO triol with a molar mass of 1200 kg / mol was prepared.

[0162] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 55 parts, under the condition of 100 °C, 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 4500 mPa-s, then add 2 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0163] Pyrolysis of polyurethane foam to recover PDO: 100 parts of prepared polyurethane foam was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160 °C and adding 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 96% PDO monomer, with a purity of 98%.

[0164] Example 19

[0165] Preparation of PPDO polyol: using glycerol ring-opening PDO, PPDO triol with a molar mass of 1500 kg / mol was prepared.

[0166] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 55 parts, under the condition of 100 °C, 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 4500 mPa-s, then add 2 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0167] Pyrolysis of polyurethane foam to recover PDO: 100 parts of prepared polyurethane foam was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 160 °C and adding 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 96% PDO monomer, with a purity of 98%.

[0168] Example 20

[0169] Preparation of PPDO polyol: using glycerol ring-opening PDO, PPDO triol with a molar mass of 1500 kg / mol was prepared.

[0170] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 50 parts, under the condition of 120°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 4500 mPa·s, then add 2 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 2h under the condition of 80°C, after demolding, further solidify for 24h under the condition of room temperature, to obtain polyurethane foam.

[0171] Example 21

[0172] Preparation of PPDO polyol: using glycerol ring-opening PDO, to prepare PPDO triol with molar mass of 5100 kg / mol.

[0173] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 0 parts, silicone oil 2 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 55 parts, under the condition of 120°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 3000 mPa·s, then add 2 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 2h under the condition of 80°C, after demolding, further solidify for 24h under the condition of room temperature, to obtain polyurethane foam.

[0174] Pyrolysis recycling of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of vacuum degree of 80 Pa, 160°C and adding 50 parts of AMPS, depolymerization for 2h, to obtain 90% of PDO monomer by pyrolysis, with purity of 96%.

[0175] Example 22

[0176] Preparation of PPDO polyol: using glycerol ring-opening PDO, to prepare PPDO triol with molar mass of 5100 kg / mol.

[0177] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 3 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 55 parts, under the condition of 120°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 5000 mPa·s, then add 2 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 2h under the condition of 80°C, after demolding, further solidify for 24h under the condition of room temperature, to obtain polyurethane foam.

[0178] Pyrolytic recovery of PDO from polyurethane foam: 100 parts of polyurethane foam was subjected to fragmentation, and depolymerized at 180 °C for 1.5 h under vacuum (100 Pa) with 3 parts of stannous octoate to give 97% PDO monomer with 98% purity.

[0179] Example 23

[0180] Preparation of PPDO polyol: PDO was ring-opened with glycerol to give PPDO triol with a molar mass of 5100 kg / mol.

[0181] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 60 parts were reacted at 120 °C under mechanical stirring at 2000 rpm for 60 s to form a prepolymer with a viscosity of 7000 mPa-s, followed by the addition of 5 parts of deionized water under mechanical stirring at 2000 rpm for 10 s, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, and further cured at room temperature for 24 h after demolding to give a polyurethane foam.

[0182] Example 24

[0183] Preparation of PPDO polyol: PDO was ring-opened with glycerol to give PPDO triol with a molar mass of 7200 kg / mol.

[0184] Preparation of polyurethane foam by isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 60 parts were reacted at 120 °C under mechanical stirring at 2000 rpm for 60 s to form a prepolymer with a viscosity of 5500 mPa-s, followed by the addition of 5 parts of deionized water under mechanical stirring at 2000 rpm for 10 s, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 2 h, and further cured at room temperature for 24 h after demolding to give a polyurethane foam.

[0185] Example 25

[0186] Preparation of PPDO polyol: PDO was ring-opened with glycerol to give PPDO triol with a molar mass of 7200 kg / mol.

[0187] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 3 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 65 parts, under the condition of 120 °C and 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 8000 mPa-s, then add 5 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain polyurethane foam.

[0188] Pyrolysis of polyurethane foam to recover PDO: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 180 °C and adding 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 96% PDO monomer, with a purity of 98%.

[0189] Glycerol Example 26

[0190] Preparation of PPDO polyol: using pentaerythritol ring-opening PDO, to prepare PPDO tetrol with a molar mass of 1200 kg / mol.

[0191] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 35 parts, under the condition of 100 °C and 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 3500 mPa-s, then add 3 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 1 h, after demolding, further solidify at room temperature for 12 h, to obtain polyurethane foam.

[0192] Pyrolysis of polyurethane foam to recover PDO: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of 85 Pa vacuum degree, 180 °C and adding 3 parts of stannous octoate, depolymerization for 1.5 h, pyrolysis to obtain 96% PDO monomer, with a purity of 99%.

[0193] Example 27

[0194] Preparation of PPDO polyol: using pentaerythritol ring-opening PDO, to prepare PPDO tetrol with a molar mass of 1200 kg / mol.

[0195] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts, under the condition of 100°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 4500 mPa·s, then add 5 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 1h under the condition of 80°C, after demolding, further solidify for 12h under the condition of room temperature, to obtain polyurethane foam.

[0196] Example 28

[0197] Preparation of PPDO polyol: using pentaerythritol ring-opening PDO, to prepare PPDO tetrol with molar mass of 1200 kg / mol.

[0198] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 3 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 40 parts, under the condition of 100°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 6000 mPa·s, then add 4 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 1h under the condition of 80°C, after demolding, further solidify for 12h under the condition of room temperature, to obtain polyurethane foam.

[0199] Pyrolysis recycling of PDO from polyurethane foam: 100 parts of polyurethane foam prepared was subjected to fragmentation treatment, under the condition of vacuum degree of 85 Pa, 200°C and addition of 2 parts of stannous octoate, depolymerization for 1.5h, to obtain 95% of PDO monomer by pyrolysis, with purity of 99%.

[0200] Example 29

[0201] Preparation of PPDO polyol: using pentaerythritol ring-opening PDO, to prepare PPDO tetrol with molar mass of 2000 kg / mol.

[0202] Preparation of polyurethane foam, using isocyanate foaming method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 45 parts, under the condition of 100°C and 2000 rpm mechanical stirring, reaction for 60s, to form a prepolymer with viscosity of 4500 mPa·s, then add 4 parts of deionized water and stir for 10s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with temperature at 80°C, solidify for 1h under the condition of 80°C, after demolding, further solidify for 12h under the condition of room temperature, to obtain polyurethane foam.

[0203] Example 30

[0204] Preparation of PPDO polyol: PPDO tetrol with a molar mass of 4000 kg / mol was prepared using pentaerythritol ring-opening PDO.

[0205] Preparation of polyurethane foam using isocyanate blowing method: PPDO polyol 100 parts, glycerol 0 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 35 parts were reacted for 60 s under 100 °C, 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 2500 mPa-s, followed by the addition of 5 parts of deionized water under 2000 rpm mechanical stirring for 10 s, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 1 h, after demolding further cured at room temperature for 12 h to obtain a polyurethane foam.

[0206] Example 31

[0207] Preparation of PPDO polyol: PPDO tetrol with a molar mass of 4000 kg / mol was prepared using pentaerythritol ring-opening PDO.

[0208] Preparation of polyurethane foam using isocyanate blowing method: PPDO polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 30 parts were reacted for 60 s under 100 °C, 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 4500 mPa-s, followed by the addition of 4 parts of deionized water under 2000 rpm mechanical stirring for 10 s, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 1 h, after demolding further cured at room temperature for 12 h to obtain a polyurethane foam.

[0209] Example 32

[0210] Preparation of PPDO polyol: PPDO tetrol with a molar mass of 6000 kg / mol was prepared using pentaerythritol ring-opening PDO.

[0211] Preparation of polyurethane foam using isocyanate blowing method: PPDO polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 45 parts were reacted for 60 s under 100 °C, 2000 rpm mechanical stirring to form a prepolymer with a viscosity of 5500 mPa-s, followed by the addition of 5 parts of deionized water under 2000 rpm mechanical stirring for 10 s, immediately poured into a mold with a temperature of 80 °C, cured at 80 °C for 1 h, after demolding further cured at room temperature for 12 h to obtain a polyurethane foam.

[0212] Pyrolytic recovery of PDO from polyurethane foam: 100 parts of polyurethane foam was subjected to fragmentation, and depolymerized at 180 °C for 1.5 h under a vacuum of 85 Pa with the addition of 3 parts of stannous octoate, and 96% PDO monomer was obtained by pyrolysis, with a purity of 98%.

[0213] Example 33

[0214] Preparation of PPDO polyol: A PPDO tetrol with a molar mass of 8000 kg / mol was prepared using ring-opening of PDO with pentaerythritol.

[0215] Preparation of polyurethane foam using isocyanate foaming method: 100 parts of PPDO polyol, 1 part of glycerol, 5 parts of silicone oil, 0.5 parts of stannous octoate, 0.5 parts of triethanolamine, and 45 parts of diisocyanate were reacted at 100 °C under mechanical stirring at 2000 rpm for 60 s to form a prepolymer with a viscosity of 7500 mPa-s, 5 parts of deionized water was then added and stirred for 10 s under mechanical stirring at 2000 rpm, and immediately poured into a mold at a temperature of 80 °C, cured at 80 °C for 1 h, and further cured at room temperature for 12 h after demolding to obtain a polyurethane foam.

[0216] Example 34

[0217] Preparation of polycaprolactone (PCL) polyol: A PCL diol with a molar mass of 3000 kg / mol was prepared using ring-opening of ε-caprolactone (ε-CL) with 1,4-butanediol.

[0218] Preparation of polyurethane foam using isocyanate foaming method: 100 parts of PCL polyol, 1 part of glycerol, 5 parts of silicone oil, 0.5 parts of stannous octoate, 0.5 parts of triethanolamine, and 45 parts of diisocyanate were reacted at 80 °C under mechanical stirring at 2000 rpm for 80 s to form a prepolymer with a viscosity of 3500 mPa-s, 3 parts of deionized water was then added and stirred for 10 s under mechanical stirring at 2000 rpm, and immediately poured into a mold at a temperature of 90 °C, cured at 90 °C for 1 h, and further cured at room temperature for 24 h after demolding to obtain a polyurethane foam.

[0219] Pyrolytic recovery of ε-CL from polyurethane foam: 100 parts of polyurethane foam was subjected to fragmentation, and depolymerized at 200 °C for 7 h under a vacuum of 85 Pa with the addition of 5 parts of stannous octoate, and 64% ε-CL monomer was obtained by pyrolysis, with a purity of 74%.

[0220] Example 35

[0221] Preparation of PCL diol: PCL diol with a molar mass of 3000 kg / mol was prepared by ring opening of ε-CL with 1,4-butanediol.

[0222] Preparation of polyurethane foam by isocyanate blowing method: PCL diol 100 parts, glycerol 2 parts, silicone oil 8 parts, stannous octoate 2 parts, triethanolamine 2 parts, diisocyanate 50 parts were reacted for 80 s under the condition of 80 °C and 5000 rpm mechanical stirring to form a prepolymer with a viscosity of 5000 mPa-s, then 3 parts of deionized water was added and stirred for 10 s under the condition of 5000 rpm mechanical stirring, immediately poured into a mold with a temperature of 90 °C, cured at 90 °C for 1 h, after demolding, further cured at room temperature for 24 h to obtain a polyurethane foam.

[0223] Pyrolysis of polyurethane foam to recover ε-CL: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, depolymerized at 250 °C for 7 h under the condition of a vacuum degree of 100 Pa and the addition of 5 parts of stannous octoate, and pyrolyzed to obtain 81% of ε-CL monomer with a purity of 92%.

[0224] Example 36

[0225] Preparation of PCL diol: PCL diol with a molar mass of 3000 kg / mol was prepared by ring opening of ε-CL with 1,4-butanediol.

[0226] Preparation of polyurethane foam by isocyanate blowing method: PCL diol 100 parts, glycerol 2 parts, silicone oil 8 parts, stannous octoate 2 parts, triethanolamine 2 parts, diisocyanate 50 parts were reacted for 80 s under the condition of 80 °C and 5000 rpm mechanical stirring to form a prepolymer with a viscosity of 5000 mPa-s, then 3 parts of deionized water was added and stirred for 10 s under the condition of 5000 rpm mechanical stirring, immediately poured into a mold with a temperature of 90 °C, cured at 90 °C for 1 h, after demolding, further cured at room temperature for 24 h to obtain a polyurethane foam.

[0227] Pyrolysis of polyurethane foam to recover ε-CL: 100 parts of the prepared polyurethane foam was subjected to fragmentation treatment, depolymerized at 250 °C for 7 h under the condition of a vacuum degree of 100 Pa and the addition of 5 parts of stannous octoate, and pyrolyzed to obtain 81% of ε-CL monomer with a purity of 92%. - [SnCl2] + (Glycine-tin chloride) ionic liquid catalyst under the condition of a vacuum degree of 100 Pa, 200 °C and the addition of 10 parts of [Gly]

[0228] Example 37

[0229] Preparation of PCL diol: PCL diol with a molar mass of 3000 kg / mol was prepared by ring opening of ε-CL with 1,4-butanediol.

[0230] Preparation of polyurethane foam by isocyanate blowing method: PCL polyol 100 parts, glycerol 1 part, silicone oil 5 parts, stannous octoate 3 parts, triethanolamine 3 parts, diisocyanate 40 parts, under the condition of 100 °C and 5000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 2000 mPa-s, then add 4 parts of deionized water and stir for 10 s under the condition of 5000 rpm mechanical stirring, immediately pour into a mold with a temperature of 100 °C, solidify at 100 °C for 1 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0231] Pyrolysis of polyurethane foam to recover ε-CL: 100 parts of prepared polyurethane foam were subjected to fragmentation treatment, under the condition of 100 Pa vacuum degree, 200 °C and 15 parts of [Gly] - [SnCl2] + (Glycine-tin chloride) ionic liquid catalyst, depolymerization for 5 h, pyrolysis to obtain 96% of ε-CL monomer with a purity of 89%.

[0232] Example 38

[0233] Preparation of PCL polyol: PCL triol with a molar mass of 3600 kg / mol was prepared by ring-opening ε-CL with glycerol.

[0234] Preparation of polyurethane foam by isocyanate blowing method: PCL polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 60 parts, under the condition of 120 °C and 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 7000 mPa-s, then add 5 parts of deionized water and stir for 10 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 80 °C, solidify at 80 °C for 2 h, after demolding, further solidify at room temperature for 24 h, to obtain a polyurethane foam.

[0235] Pyrolysis of polyurethane foam to recover ε-CL: 100 parts of prepared polyurethane foam were subjected to fragmentation treatment, under the condition of 80 Pa vacuum degree, 250 °C and 5 parts of stannous octoate, depolymerization for 7 h, pyrolysis to obtain 81% of ε-CL monomer with a purity of 93%.

[0236] Example 39

[0237] Preparation of poly(L-lactide) (PLLA) polyol: PLLA diol with a molar mass of 3000 kg / mol was prepared by ring-opening L-lactide (LLA) with 1,4-butanediol;

[0238] Preparation of polyurethane foam by isocyanate foaming method: PLLA polyol 100 parts, glycerol 1 part, silicone oil 3 parts, stannous octoate 2 parts, triethanolamine 2 parts, diisocyanate 45 parts, under the condition of 160°C and 5000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 3500 mPa·s, then add 3 parts of deionized water and stir for 10 s under the condition of 5000 rpm mechanical stirring, immediately pour into a mold with a temperature of 120°C, solidify at 120°C for 2 h, after demolding, further solidify at room temperature for 36 h, to obtain a polyurethane foam.

[0239] Pyrolysis of polyurethane foam to recover LLA: 100 parts of prepared polyurethane foam were subjected to fragmentation treatment, depolymerization for 5 h under the condition of 100 Pa vacuum degree, 200°C and 3 parts of stannous octoate, and pyrolysis to obtain 72% of LLA monomer, with a purity of 81%.

[0240] Example 40

[0241] Preparation of PLLA polyol: PLLA diol with a molar mass of 3000 kg / mol was prepared by ring-opening LLA using 1,4-butanediol.

[0242] Preparation of polyurethane foam by isocyanate foaming method: PLLA polyol 100 parts, glycerol 2 parts, silicone oil 5 parts, stannous octoate 0.5 parts, triethanolamine 0.5 parts, diisocyanate 50 parts, under the condition of 160°C and 2000 rpm mechanical stirring, reaction for 60 s, to form a prepolymer with a viscosity of 2000 mPa·s, then add 8 parts of deionized water and stir for 15 s under the condition of 2000 rpm mechanical stirring, immediately pour into a mold with a temperature of 120°C, solidify at 120°C for 2 h, after demolding, further solidify at room temperature for 36 h, to obtain a polyurethane foam.

[0243] Pyrolysis of polyurethane foam to recover LLA: 100 parts of prepared polyurethane foam were subjected to fragmentation treatment, depolymerization for 5 h under the condition of 100 Pa vacuum degree, 200°C and addition of 5 parts of stannous octoate, and pyrolysis to obtain 86% of LLA monomer, with a purity of 87%.

[0244] Example 41

[0245] Preparation of PLLA polyol: PLLA triol with a molar mass of 3600 kg / mol was prepared by ring-opening LLA using glycerol.

[0246] The preparation of the polyurethane foam is carried out by using the isocyanate foaming method: 100 parts of PLLA polyol, 3 parts of glycerol, 5 parts of silicone oil, 0.5 parts of stannous octoate, 0.5 parts of triethanolamine, and 55 parts of diisocyanate are reacted at 120°C under the condition of 2000 rpm mechanical stirring for 60s to form a prepolymer with a viscosity of 7000 mPa·s, then 2 parts of deionized water is added and stirred for 10s under the condition of 2000 rpm mechanical stirring, and immediately poured into a mold with a temperature of 80°C, and cured at 80°C for 2h, and further cured at room temperature for 24h after demolding to obtain the polyurethane foam.

[0247] Thermal pyrolysis recovery of LLA from the polyurethane foam: 100 parts of the prepared polyurethane foam is subjected to fragmentation treatment, and depolymerized at 200°C under the condition of 100 Pa vacuum degree and 5 parts of stannous octoate for 5h to obtain 85% of LLA monomer with a purity of 90%.

[0248] II. Some detection indexes and detection results of each embodiment are as follows:

[0249] 1. The structure of the polyurethane foam is detected, and the detection results are as shown in Figure 1 and Figure 2 .

[0250] Figure 1 The physical map, scanning electron microscope photo and pore size distribution map of the PPDO-based polyurethane foam prepared in Example 12 are shown in Figure 2 The physical map, scanning electron microscope photo and pore size distribution map of the PCL-based polyurethane foam prepared in Example 35 are shown in

[0251] According to Figure 1 and Figure 2 , in the embodiments of the present application, the polyurethane foam is directly prepared by chemical foaming process from aliphatic polycyclic ester polyol, the formed holes are mainly regular spherical holes, and the pore size of the holes formed by foaming is mainly distributed in 200μm, wherein the pore size of the large holes can reach 1000μm, 1200μm or even 1500μm.

[0252] 2. The mechanical property related indexes of the polyurethane foam are detected, and the detection results are as shown in Figures 3-7 and Table 1.

[0253] Figure 3 The X-ray diffraction spectrum of the polyurethane foam and PPDO prepared in Examples 6, 8, 12 and 15 is shown in Figure 4 The DSC first heating curve of the polyurethane foam prepared in Examples 6, 7, 8, 9, 12, 13, 15 and 16 is shown in

[0254] According to Figure 3 and Figure 4It can be known that, in the embodiments of the present application, the crystallization of the soft segment of the polyurethane foam can be regulated by regulating the molar mass of the aliphatic polycyclic ester polyol, the amount of the foam crosslinking agent, and the like, so as to realize the regulation of the mechanical properties of the polyurethane foam.

[0255] Figure 5 Cyclic compression stress-strain curves of the PPDO-based polyurethane foams prepared for Example 12.

[0256] According to Figure 5 It can be known that the PPDO-based polyurethane foams prepared in the embodiments of the present application have good cyclic compression strain performance.

[0257] Figure 6 Compression strength and compression modulus column chart of the polyurethane foams prepared for Examples 6, 7, 8, 9, 12, 13, 14, 15, 16, 29; Figure 7 Rebound rate column chart of the polyurethane foams prepared for Examples 6, 7, 8, 9, 12, 13, 14, 15, 16, 29.

[0258] The compression strength and the rebound rate are measured by a universal mechanical testing machine. The test standard for the compression strength is that the test is performed when the compression strain is 80% of the initial height; the test standard for the rebound rate is that the compression strain is maintained at 50% for 3 minutes, then the pressure is removed and the rebound rate is calculated according to the rebound degree after 3 minutes of standing.

[0259] According to Figure 6 and Figure 7 It can be known that, in the embodiments of the present application, the crystallization of the soft segment of the polyurethane foam can be regulated by regulating the molar mass of the aliphatic polycyclic ester polyol, the amount of the foam crosslinking agent, and the like, so as to realize the regulation of the mechanical properties of the polyurethane foam.

[0260] Specifically, the statistical results of the mechanical property test of the polyurethane foam are shown in Table 1, and in order to intuitively compare and analyze, some conditions of the preparation method are correspondingly counted in Table 1.

[0261] Table 1. Conditions of the preparation method and the statistical results of the mechanical property test

[0262]

[0263]

[0264] Note: In Table 1, the mass fraction of the foam crosslinking agent is converted according to 100 mass fractions of the aliphatic polycyclic ester polyol.

[0265] As shown in Table 1, when the amount of foam crosslinking agent is the same, as the molar mass of aliphatic polycyclic ester polyol increases, the apparent density, gel content, and compressive strength of polyurethane foam increase, while the resilience first increases and then decreases. When the molar mass of aliphatic polycyclic ester polyol is the same, as the amount of foam crosslinking agent increases, the apparent density, gel content, and compressive strength of polyurethane foam increase. The resilience rate increases when the molar mass of aliphatic polycyclic ester polyol is small, and decreases when the molar mass of aliphatic polycyclic ester polyol is large.

[0266] 3. The pyrolysis recycling performance of polyurethane foam was tested, and the test results are as follows: Figure 8 As shown in Table 2.

[0267] Figure 8 The 1H NMR spectra of PDO obtained from the pyrolysis recovery of polyurethane foam in Examples 9 and 15 are shown.

[0268] according to Figure 8 As can be seen, in the embodiments of this application, the cyclic ester monomer was well recovered through pyrolysis.

[0269] Specifically, the recovery results of cyclic ester monomers are shown in Table 2. For intuitive comparison and analysis, some conditions of the preparation method and recovery method are statistically summarized in Table 2.

[0270] Table 2. Experimental conditions and recovery results

[0271]

[0272]

[0273] Note: The mass fraction of pyrolysis catalyst in Table 2 is calculated based on 100 parts by mass of polyurethane foam.

[0274] As can be seen from the comparison between Example 1 and other examples, during pyrolysis recovery, the recovery rate of cyclic ester monomers is significantly improved after adding a pyrolysis catalyst compared to the case without the addition of a pyrolysis catalyst.

[0275] When organometallic catalysts are used for pyrolysis, the amount of catalyst used is small, the recovery rate of cyclic ester monomers is usually high, and the purity of the recovered cyclic ester monomers is usually high. Specifically:

[0276] In Examples 5-7, the recovery rate of cyclic ester monomers increased with increasing pyrolysis temperature.

[0277] In Examples 5 and 8-10, the recovery rate of cyclic ester monomers increased with the increase of the amount of pyrolysis catalyst.

[0278] In Examples 5-13, 18-19, 22-25, based on the PPDO-based polyurethane foam, when the amount of pyrolysis catalyst is low, the purity of the recovered cyclic ester monomer can reach 98% or even 99%; in Example 10, the amount of pyrolysis catalyst is relatively large, resulting in a certain degree of reduction in the purity of the recovered cyclic ester monomer.

[0279] Comparing the PPDO-based polyurethane foam, the PCL-based polyurethane foam, and the examples of the PCL-based polyurethane foam, when pyrolyzing the PPDO-based polyurethane foam, a higher recovery rate of the cyclic ester monomer can be achieved with a lower pyrolysis temperature, a shorter pyrolysis time, and a smaller amount of pyrolysis catalyst, and the purity of the recovered cyclic ester monomer is also higher, indicating that the PPDO-based polyurethane foam has better pyrolysis recovery performance.

[0280] When the pyrolysis catalyst is an ionic liquid, compared with the pyrolysis catalyst being an organic metal catalyst, the amount of pyrolysis catalyst is larger, and the upper limit of the purity of the recovered cyclic ester monomer is relatively lower. Among them:

[0281] In Examples 34-38, based on the PCL-based polyurethane foam, compared with the pyrolysis catalyst being a metal catalyst, when the pyrolysis catalyst is [Gly] - [SnCl2] + ionic liquid, a higher recovery rate of the cyclic ester monomer can be achieved, indicating that [Gly] - [SnCl2] + ionic liquid has better pyrolysis recovery performance for the PCL-based polyurethane foam.

[0282] 4, The degradation performance of the polyurethane foam was detected, and the detection results were as follows Figure 9 and Figure 10 .

[0283] The polyurethane foam was degraded by natural landfill in soil, Figure 9 the pictures of the PPDO-based polyurethane foams prepared in Examples 6, 8, and 12 and the commercial polyurethane foams before degradation, Figure 10 the pictures of the PPDO-based polyurethane foams prepared in Examples 6, 8, and 12 and the commercial polyurethane foams after 7 days of degradation.

[0284] Among them, the commercial polyurethane foams in the upper row of the figure, the left is a commercial polyurethane hard foam, and the right is a commercial polyurethane soft foam; the PPDO-based polyurethane foams in the lower row of the figure correspond to Examples 6, 8, and 12 from left to right. The details of the commercial polyurethane foams are as follows: the commercial polyurethane foams were all purchased on Taobao, the density of the commercial polyurethane hard foam was 150 kg / m 3 , the brand was Hongsheng, and the model was PU; the brand of the commercial polyurethane soft foam was Jixin Sponge.

[0285] According toFigure 9 and Figure 10 It can be known that the polyurethane foam prepared in the embodiment has good degradation performance in the natural environment.

[0286] 5, the recovery performance of the pyrolysis residue was tested. Figure 11 The adhesion strength of the ionic adhesive formed by the interaction of AMPS and pyrolysis residue in Example 2 to different substrates.

[0287] According to Figure 11 It can be known that the mixture of AMPS and pyrolysis residue has strong adhesion performance to various substrates and can be used as an ionic adhesive.

[0288] The above-described embodiments are part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

Claims

1. A method for producing a polyurethane foam which is recyclable and biodegradable, characterized by, Comprising: ring-opening polymerization of a cyclic ester monomer initiated by an initiator to obtain a fatty poly cyclic ester polyol; preparing a polyurethane foam directly from the fatty poly cyclic ester polyol by a chemical foaming process.

2. The process for the preparation of a recyclable and biodegradable polyurethane foam according to claim 1, characterized in that, satisfy one or more of the following conditions (a1)~(a3); (a1) the cyclic ester monomer comprises one or more of p-dioxanone, ε-caprolactone, γ-butyrolactone, β-butyrolactone, lactide, glycolide; (a2) the fatty poly cyclic ester polyol has a molar mass of 400~12000 kg / mol; (a3) the initiator comprises one or more of 1,4-butanediol, 1,6-hexanediol, glycerol, pentaerythritol, PLA polyol and copolymer polyol thereof, PCL polyol and copolymer polyol thereof, PGA polyol and copolymer polyol thereof, PEG polyol and copolymer polyol thereof, PPDO polyol and copolymer polyol thereof.

3. The process for the preparation of a recyclable and biodegradable polyurethane foam according to claim 1 or 2, characterized in that, the chemical foaming process satisfies the following conditions (b1) or (b2); (b1) the chemical foaming process adopts an isocyanate foaming method, which comprises: reacting 100 parts by mass of the fatty poly cyclic ester polyol, 0~10 parts by mass of a foam crosslinking agent, 0.1~10 parts by mass of silicone oil, 0.1~8 parts by mass of an organic metal compound catalyst, 0.1~8 parts by mass of an organic base catalyst, and 10~100 parts by mass of diisocyanate at 40~220℃ under mechanical stirring at 200~15000 rpm for 5~300 s to form a prepolymer with a viscosity of 200~20000 mPa·s; then adding 0.3~10 parts by mass of water and stirring under mechanical stirring at 200~15000 rpm for 5~300 s; then immediately pouring into a mold with a temperature of room temperature~150℃ and curing at room temperature~150℃ for 1~48 h; (b2) the chemical foaming process adopts a cyclic carbonate foaming method, which comprises: reacting 100 parts by mass of the fatty poly cyclic ester polyol, 0~10 parts by mass of a foam crosslinking agent, 0.1~10 parts by mass of silicone oil, 0.1~8 parts by mass of an inorganic base catalyst, and 10~120 parts by mass of a multifunctional five-membered ring carbonate at 40~220℃ for 5~180 min; then adding water or mercaptan 0.1~100 parts by mass and reacting under mechanical stirring at 200~15000 rpm for 1~30 min; then immediately pouring into a mold with a temperature of room temperature~150℃ and curing at room temperature~150℃ for 1~48 h.

4. The process for the preparation of a recyclable and biodegradable polyurethane foam according to claim 3, characterized in that, satisfy one or more of the following conditions (c1)~(c6); (c1) the foam crosslinking agent is a polyol; optionally, the foam crosslinking agent comprises one or more of glycerol, pentaerythritol, PLA polyol and copolymer polyol thereof, PCL polyol and copolymer polyol thereof, PGA polyol and copolymer polyol thereof, PEG polyol and copolymer polyol thereof, PPDO polyol and copolymer polyol thereof; (c2) the organic metal compound catalysts include one or more of dibutyltin dilaurate, di-n-octyltin dilaurate, stannous octoate, dibutyltin diacetate, dibutyltin mercaptide, bismuth octoate, tributyl bismuth, dibutyl bismuth dilaurate; (c3) the organic base catalysts include one or more of 1,8-diazabicycloundec-7-ene, triethylamine, triethanolamine, ethylenediamine, trimethyl aniline, triethylene diamine, tetramethyl butanediamine; (c4) the diisocyanates include one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, L-lysine diisocyanate; (c5) the inorganic base catalysts include one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate; (c6) the mercaptans include one or more of methyl mercaptan, ethyl mercaptan, 1-propanethiol, n-butyl mercaptan, isobutyl mercaptan, phenyl mercaptan, 2-mercaptoethanol, mercaptoacetic acid, 2-mercaptobenzothiazole, mercaptopropionic acid, mercaptoethylamine, thioglycerol.

5. A polyurethane foam that is recyclable and biodegradable, characterized in that, The method for preparing the recyclable and biodegradable polyurethane foam according to any one of claims 1-4, wherein the soft segment of the recyclable and biodegradable polyurethane foam comprises aliphatic polylactone segments; Optionally, the pores in the recyclable and biodegradable polyurethane foam are mainly spherical pores. Optionally, the pore size distribution of the pores in the recyclable and biodegradable polyurethane foam ranges from 50 to 15000 μm.

6. A recycling method of the recyclable and biodegradable polyurethane foam according to claim 5, characterized by, The method comprises: pyrolysis recycling of the recyclable and biodegradable polyurethane foam; The pyrolysis recycling comprises: adding the equivalent prepared foam, adding a pyrolysis catalyst, and depolymerizing at 10-2000 Pa and 60-300°C for 0.1-72 h to obtain the lactone monomers. Optionally, the vacuum degree during the pyrolysis recycling is 50-150 Pa. Optionally, the temperature during the pyrolysis recycling is 150-250°C. Optionally, the depolymerization time during the pyrolysis recycling is 1-8 h.

7. The recycling method of the recyclable and biodegradable polyurethane foam according to claim 6, characterized by, The pyrolysis catalyst includes one or more of organic metal, inorganic non-metal, organic acid, inorganic acid, organic base, inorganic base, organic salt, inorganic salt, and ionic liquid catalyst. Optionally, the pyrolysis catalyst comprises one or more of tin chloride, stannous octoate, dibutyltin dilaurate, zinc sulfate, zinc nitrate, zinc acetate, zinc bromide, sodium methoxide, potassium methoxide, sodium hydroxide, potassium hydroxide, zinc acetate, zinc oxide, titanate, antimony compound, sulfuric acid, hydrochloric acid, phosphoric acid, phosphate, oxalic acid, citric acid, p-toluenesulfonic acid, p-toluene sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid salt, glycine-tin chloride, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, tetrabutylammonium bromide, tetrabutylammonium chloride, tetramethylammonium chloride, tributylmethylphosphonium chloride, tributylmethylphosphonium bromide, aminoimidazolium ionic liquid, amino-functionalized quaternary ammonium salt, choline chloride-urea, choline chloride-glycol.

8. The recycling method of the recyclable and biodegradable polyurethane foam according to claim 7, characterized by, (d1) the pyrolysis catalyst is an organometallic catalyst, and the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(0.1-10); (d1) the pyrolysis catalyst is an organometallic catalyst, and the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(0.1-10); Optionally, the organometallic catalyst is stannous octoate, and the cyclic ester monomer is p-dioxanone. Optionally, the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(1-5). Optionally, the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(2-3). (d2) the pyrolysis catalyst is an organic acid catalyst or an ionic liquid catalyst, and the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(10-100); Optionally, the organic acid catalyst is 2-acrylamido-2-methylpropanesulfonic acid, and the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(30-100). Optionally, the ionic liquid catalyst is glycine-tin chloride, the cyclic ester monomer is ε-caprolactone or L-lactide, and the mass ratio of the recyclable and biodegradable polyurethane foam to the pyrolysis catalyst is 100:(10-15).

9. The recycling method of the recyclable and biodegradable polyurethane foam according to any one of claims 6 to 8, characterized by, Further comprising: After the pyrolysis recycling, the pyrolysis residues are subjected to chemical solvolysis recycling, or the pyrolysis residues are directly upgraded to recover ionomer adhesives; The chemical solvolysis recycling comprises one or more of alcoholysis, acidolysis, hydrolysis, ammonolysis, and ionic liquid catalytic depolymerization. Optionally, the recovery product of the chemical solvolysis recycling comprises one or more of polyols and polyamines.

10. Use of the recyclable and biodegradable polyurethane foam according to claim 5, characterized in that, The recyclable and biodegradable polyurethane foam is applied to the manufacturing of cushion packaging, marine engineering, shipbuilding industry, medical and health materials, building insulation materials, vehicle interior materials, or furniture materials. Optionally, the cushion packaging is used for the packaging of fragile products, electronic appliances, precision instruments, or food preservation.

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