1. A graphene oxide/fly ash modified regenerated polyurethane composite material comprises a regenerated polyurethane foam material and a graphene oxide/fly ash cross-linked hybrid dispersed in the regenerated polyurethane foam material.

2. The graphene oxide/fly ash modified recycled polyurethane composite material as claimed in claim 1, wherein the mass ratio of the graphene oxide to the fly ash in the graphene oxide/fly ash cross-linked hybrid is 1-30: 1 to 10.

3. The graphene oxide/fly ash modified recycled polyurethane composite material as claimed in claim 1, wherein the mass ratio of the recycled polyurethane foam material to the graphene oxide/fly ash cross-linked hybrid is 100-300: 1-100.

4. The preparation method of the graphene oxide/fly ash modified recycled polyurethane composite material as claimed in any one of claims 1 to 3, comprising the following steps:

(1) mixing waste polyurethane foam with graphene oxide/fly ash hybrid, micromolecular alcohol and decomposition aid, and performing degradation reaction to obtain a degradation product;

(2) and mixing the degradation product with a foaming auxiliary agent and an isocyanate compound, and foaming to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

5. The preparation method according to claim 4, wherein the preparation method of the graphene oxide/fly ash hybrid comprises the following steps:

(a) mixing the fly ash with an acid solution, and acidifying to obtain acidified fly ash;

(b) ultrasonically mixing the acidified fly ash with ethanol and a coupling agent to obtain activated fly ash;

(c) and ultrasonically mixing the activated fly ash, graphene oxide and an organic solvent, and carrying out coupling reaction to obtain the graphene oxide/fly ash cross-linked hybrid.

6. The preparation method according to claim 4, wherein the small molecule alcohol is one or more of ethanolamine, propylene glycol, butylene glycol and diglycerin; the decomposition aid is one or more of potassium hydroxide, magnesium hydroxide, sodium acetate, triethylamine and triethanolamine;

the mass ratio of the waste polyurethane foam to the graphene oxide/fly ash hybrid to the micromolecular alcohol to the decomposition aid is 100-300: 1-100: 50-150: 10-50.

7. The preparation method according to claim 4, wherein the temperature of the degradation reaction is 80-150 ℃ and the time is 1-8 h.

8. The preparation method according to claim 4, wherein the foaming auxiliary agent comprises a chain extender, a foaming agent, a catalyst and a foam stabilizer;

the isocyanate compound is one or more of diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate and toluene diisocyanate.

9. The preparation method of the modified polyurethane foam material according to claim 8, wherein the mass ratio of the degradation product to the chain extender, the foaming agent, the catalyst and the foam stabilizer is 20-50: 1-8: 4-20: 1-8: 2-10;

the mass ratio of the degradation product to the isocyanate compound is 30: 30-225.

10. The preparation method according to claim 4 or 9, wherein the foaming temperature is 160-250 ℃, the foaming time is 0.5-2.5 h, and the foaming pressure is 0.1-0.3 MPa.

Background

The application range of the polyurethane foam plastic almost permeates various industries of national economy, and particularly becomes one of indispensable important materials in the fields of buildings, traffic, household appliances and the like. While the polyurethane material is widely applied, a large amount of polyurethane foam solid waste is generated, and the polyurethane foam solid waste can pollute soil and the atmospheric environment, so that the problem of recycling and treating waste polyurethane foam is gradually paid high attention to people.

The existing treatment method of waste polyurethane foam mainly comprises a physical recovery method and a chemical recovery method. The physical recovery method mainly changes the physical form of the waste materials and then directly uses the waste materials, and realizes the secondary utilization of the waste materials by adopting the modes of bonding forming, hot press forming and using as fillers, but the actual effective utilization rate is low because the performance of the waste polyurethane is greatly reduced.

The chemical recovery method adopts alcoholysis, aminolysis, hydrolysis or pyrolysis to decompose the waste polyurethane into polyurethane degradation raw materials, and then synthesize the degradation raw materials into regenerated polyurethane materials, so as to realize the recycling of the materials (such as patents CN107955206A and CN 103012838A). However, the mechanical strength of the regenerated polyurethane foam is low, which limits the use of the regenerated polyurethane foam.

Disclosure of Invention

In view of the above, the present invention aims to provide a graphene oxide/fly ash modified recycled polyurethane composite material and a preparation method thereof. The graphene oxide/fly ash modified regenerated polyurethane composite material provided by the invention has good compressive strength and lower heat conductivity coefficient.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a graphene oxide/fly ash modified regenerated polyurethane composite material which comprises a regenerated polyurethane foam material and a graphene oxide/fly ash cross-linked hybrid dispersed in the regenerated polyurethane foam material.

Preferably, the mass ratio of the graphene oxide to the fly ash in the graphene oxide/fly ash cross-linked hybrid is 1-30: 1 to 10.

Preferably, the mass ratio of the regenerated polyurethane foam material to the graphene oxide/fly ash cross-linked hybrid is 100-300: 1-100.

The invention provides a preparation method of the graphene oxide/fly ash modified regenerated polyurethane composite material, which comprises the following steps:

(1) mixing waste polyurethane foam with graphene oxide/fly ash hybrid, micromolecular alcohol and decomposition aid, and performing degradation reaction to obtain a degradation product;

(2) and mixing the degradation product with a foaming auxiliary agent and an isocyanate compound, and foaming to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

Preferably, the preparation method of the graphene oxide/fly ash hybrid comprises the following steps:

(a) mixing the fly ash with an acid solution, and acidifying to obtain acidified fly ash;

(b) ultrasonically mixing the acidified fly ash with ethanol and a coupling agent to obtain activated fly ash;

(c) and ultrasonically mixing the activated fly ash, graphene oxide and an organic solvent, and carrying out coupling reaction to obtain the graphene oxide/fly ash cross-linked hybrid.

Preferably, the small molecular alcohol is one or more of ethanolamine, propylene glycol, butanediol and diglycerol; the decomposition aid is one or more of potassium hydroxide, magnesium hydroxide, sodium acetate, triethylamine and triethanolamine;

the mass ratio of the waste polyurethane foam to the graphene oxide/fly ash hybrid to the micromolecular alcohol to the decomposition aid is 100-300: 1-100: 50-150: 10-50.

Preferably, the temperature of the degradation reaction is 80-150 ℃ and the time is 1-8 h.

Preferably, the foaming auxiliary agent comprises a chain extender, a foaming agent, a catalyst and a foam stabilizer;

the isocyanate compound is one or more of diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate and toluene diisocyanate.

Preferably, the mass ratio of the degradation product to the chain extender, the foaming agent, the catalyst and the foam stabilizer is 20-50: 1-8: 4-20: 1-8: 2-10;

the mass ratio of the degradation product to the isocyanate compound is 30: 30-225.

Preferably, the foaming temperature is 160-250 ℃, the time is 0.5-2.5 h, and the pressure is 0.1-0.3 MPa.

The invention provides a graphene oxide/fly ash modified regenerated polyurethane composite material which comprises a regenerated polyurethane foam material and a graphene oxide/fly ash cross-linked hybrid dispersed in the regenerated polyurethane foam material. According to the invention, the graphene oxide/fly ash cross-linked hybrid is used as the filler, so that the problem that the graphene oxide is easy to agglomerate can be avoided, and the graphene oxide/fly ash cross-linked hybrid is easier to disperse in the regenerative polyurethane foam material; the graphene oxide/fly ash cross-linked hybrid has a synergistic modification effect, and can simultaneously improve the compression strength and the heat preservation performance of the regenerated polyurethane composite material when being used as a modified filler. ExamplesThe result shows that the maximum compression strength of the graphene oxide/fly ash modified regenerated polyurethane composite material provided by the invention is 0.2898MPa, and the minimum thermal conductivity is 0.01486 W.m^-1·K^-1。

The invention provides a preparation method of a graphene oxide/fly ash modified regenerated polyurethane composite material, which comprises the steps of mixing waste polyurethane foam, a graphene oxide/fly ash hybrid, small molecular alcohol and a decomposition aid, and carrying out degradation reaction to obtain a degradation product; and then mixing the degradation product with a foaming auxiliary agent, and foaming to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material. The method is simple to operate and easy to realize industrial mass production.

Drawings

FIG. 1 is a scanning electron micrograph of fly ash;

FIG. 2 is a scanning electron micrograph of a graphene oxide/fly ash cross-linked hybrid;

FIG. 3 is an infrared image of fly ash;

FIG. 4 is an infrared image of a graphene oxide/fly ash modified recycled polyurethane composite.

Detailed Description

The invention provides a graphene oxide/fly ash modified regenerated polyurethane composite material which comprises a regenerated polyurethane foam material and a graphene oxide/fly ash cross-linked hybrid dispersed in the regenerated polyurethane foam material.

In the invention, the mass ratio of the graphene oxide to the fly ash in the graphene oxide/fly ash cross-linked hybrid is preferably 1-30: 1 to 10, more preferably 5 to 20:3 to 8, and still more preferably 10 to 15: 5. In the invention, the mass ratio of the regenerated polyurethane foam material to the graphene oxide/fly ash cross-linked hybrid is preferably 100-300: 1-100, more preferably 150-250: 10 to 80, and more preferably 200 to 220:30 to 60.

The invention provides a preparation method of the graphene oxide/fly ash modified regenerated polyurethane composite material, which comprises the following steps:

(1) mixing waste polyurethane foam with graphene oxide/fly ash hybrid, micromolecular alcohol and decomposition aid, and performing degradation reaction to obtain a degradation product;

(2) and mixing the degradation product with a foaming auxiliary agent and an isocyanate compound, and foaming to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

The method comprises the steps of mixing waste polyurethane foam, oxidized graphene/fly ash hybrid, micromolecular alcohol and a decomposition aid, and carrying out degradation reaction to obtain a degradation product. In the present invention, the method for preparing the graphene oxide/fly ash hybrid preferably comprises the following steps:

(a) mixing the fly ash with an acid solution, and acidifying to obtain acidified fly ash;

(b) ultrasonically mixing the acidified fly ash with ethanol and a coupling agent to obtain activated fly ash;

(c) and ultrasonically mixing the activated fly ash, graphene oxide and an organic solvent, and carrying out coupling reaction to obtain the graphene oxide/fly ash cross-linked hybrid.

The invention preferably mixes the fly ash with acid liquor to acidify and obtain the acidified fly ash. In the invention, the particle size of the fly ash is preferably 500-5000 meshes, and more preferably 1000-3000 meshes. Before mixing, the fly ash is preferably dried at the temperature of 50-80 ℃, more preferably 60-70 ℃ for 12-24 hours, and more preferably 6-20 hours.

In the invention, the acid solution is preferably a hydrochloric acid solution, and the concentration of the hydrochloric acid solution is preferably 0.1-0.6 mol/L, and more preferably 0.2-0.4 mol/L. The invention has no special requirement on the dosage of the hydrochloric acid solution, and the fly ash can be completely immersed. The invention does not require any particular mixing means, such as stirring, known to the person skilled in the art.

In the invention, the acidification is preferably carried out under a standing condition, and the acidification time is preferably 10-30 min, and more preferably 20 min.

After the acidified fly ash is obtained, the acidified fly ash, ethanol and a coupling agent are preferably ultrasonically mixed to obtain the activated fly ash. In the present invention, the volume concentration of ethanol is preferably 95%; the mass ratio of the volume of the ethanol to the acidified fly ash is preferably 10-30 mL:1g, and more preferably 15-25 mL:1 g.

The coupling agent is preferably a silane coupling agent and/or a titanate coupling agent. In the invention, the silane coupling agent is preferably one or more of KH550, KH560, KH570, KH792, DL602 and DL171, and the titanate coupling agent is preferably one or more of triisostearoyl isopropyl titanate, isopropyl tri (dioctyl pyrophosphoryl) titanate, oxoacetoxy titanate, dioxoethylene titanate and tetraisopropyl (dilauryl phosphite) titanate. In the present invention, the mass ratio of the coupling agent to the acidified fly ash is preferably 1: 10-20, and more preferably 1: 15.

In the invention, the power of ultrasonic mixing is preferably 100-300W, and more preferably 200W; the ultrasonic mixing time is preferably 1-3 h, and more preferably 2 h.

After the ultrasonic mixing, the invention preferably washes, filters and dries the obtained mixed liquid in sequence to obtain the activated fly ash solid. In the invention, the washing detergent is preferably deionized water, and the filtering mode is preferably suction filtration; the drying method has no special requirement, and can be realized by using a drying method well known in the art, wherein the drying time is preferably 24-48 hours, and more preferably 32-40 hours.

After the activated fly ash is obtained, the activated fly ash, the graphene oxide and the organic solvent are preferably ultrasonically mixed for coupling reaction, so that the graphene oxide/fly ash cross-linked hybrid is obtained. The preparation method of the graphene oxide has no special requirements, and the graphene oxide can be prepared by a method known by a person skilled in the art, such as a Brodie method, a Staudenmaier method or a Hummers method. In the invention, the thickness of the graphene oxide sheet is preferably 0.3-1 nm, more preferably 0.5-0.8 nm, and the diameter of the sheet is preferably 0.2-50 μm, more preferably 1-30 μm, and even more preferably 2-20 μm. In the invention, the mass ratio of the graphene oxide to the activated fly ash is preferably 1-30: 1 to 10, more preferably 5 to 20:3 to 8, and still more preferably 10 to 15: 5.

In the present invention, the organic solvent is preferably one or more of dimethylformamide, dimethylacetamide, toluene, xylene, and methanol. The method has no special requirement on the dosage of the organic solvent, and can ensure that the activated fly ash and the graphene oxide are uniformly dispersed.

In the invention, the power of ultrasonic mixing is preferably 100-300W, and more preferably 200W; the ultrasonic mixing time is preferably 1-3 h, and more preferably 2 h. In the invention, the coupling reaction is preferably carried out under the condition of stirring, the temperature of the coupling reaction is preferably 80-100 ℃, more preferably 90 ℃, and the time is preferably 8-30 min, more preferably 10-20 min.

After the coupling reaction, the obtained coupling reaction solution is preferably washed, filtered and dried in sequence to obtain the graphene oxide/fly ash cross-linked hybrid solid. In the present invention, the washing detergent is preferably absolute ethyl alcohol; the present invention does not require any particular filtration means, and filtration means known to those skilled in the art may be used. According to the invention, the drying is preferably carried out in a vacuum drying oven, the drying temperature is preferably 50-80 ℃, more preferably 60-70 ℃, and the drying time is preferably 12-48 h, more preferably 24-36 h.

The method comprises the steps of mixing waste polyurethane foam, oxidized graphene/fly ash hybrid, micromolecular alcohol and a decomposition aid, and carrying out degradation reaction to obtain a degradation product. The waste polyurethane foam of the present invention has no special requirement, and polyurethane foam known to those skilled in the art, such as polyurethane soft foam, polyurethane hard foam, and polyurethane semi-hard foam, can be used. The polyurethane foam is preferably pulverized, washed, filtered and dried in this order before the mixing is performed. The invention has no special requirements on the crushing mode, and the crushing mode known by the technicians in the field can be used; the particle size of the crushed polyurethane is preferably less than or equal to 10 mm. The present invention does not require a particular manner of operation for the washing, filtering and drying, and the above-described manner known to those skilled in the art can be used.

In the invention, the small molecular alcohol is preferably one or more of ethanolamine, propylene glycol, butanediol and diglycerol; the hydrolysis aid is preferably one or more of potassium hydroxide, magnesium hydroxide, sodium acetate, triethylamine and triethanolamine. According to the invention, the waste polyurethane foam can be alcoholyzed into the degradation product polyol by the micromolecular alcohol and the hydrolysis promoter.

In the invention, the mass ratio of the waste polyurethane foam, the graphene oxide/fly ash hybrid, the small molecular alcohol and the decomposition aid is preferably 100-300: 1-100: 50-150: 10-50, more preferably 150-250: 10-80: 60-80: 20-40, and further preferably 200: 40-60: 70: 30. In the invention, the temperature of the degradation reaction is preferably 80-150 ℃, more preferably 100-120 ℃, and the time is preferably 1-8 hours, more preferably 3-6 hours. According to the invention, the degradation reaction is preferably carried out under the condition of stirring, and the stirring speed is preferably 80-200 r/min, and more preferably 100-150 r/min.

After the degradation reaction, the degradation reaction liquid is preferably subjected to ultrasonic dispersion, wherein the power of the ultrasonic dispersion is preferably 100-300W, and more preferably 200W; the time is preferably 1 to 3 hours, and more preferably 2 hours.

After the degradation product is obtained, the degradation product is mixed with a foaming auxiliary agent and an isocyanate compound for foaming to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material. In the present invention, the foaming aid preferably includes a chain extender, a foaming agent, a catalyst and a foam stabilizer. In the invention, the chain extender is preferably one or more of 1, 4-butanediol, 1, 6-hexanediol, glycerol, trimethylolpropane, diethylene glycol, triethylene glycol, neopentyl glycol, sorbitol, diethylaminoethanol, ethylenediamine and N, N-dihydroxy (diisopropyl) aniline; the foaming agent is preferably one or more of pentane, 1,1,1,3, 3-pentafluorobutane, 1,1,1, 2-tetrafluoroethane, N-Azobisisobutyronitrile (AZDN), dicyandiamide, N-butane, 1, 1-dichloro-1-fluoroethane, propane-butane, dimethyl ether, water and azodicarbonamide; the catalyst is preferably one or more of tris (dimethylaminopropyl) hexahydrotriazine, stannous octoate, dimethylethanolamine, N, N, N '-pentamethyldiethylenetriamine, triethylenediamine, N, N-dimethylpiperazine, triethylenediamine, dimethylaminoethylether, pentamethyldiethylenetriamine, 2' -dimorpholinodiethylether and N, N-dimethylbenzylamine; the foam stabilizer is preferably one or more of silicone oil L-600, silicone oil SE-232, silicone oil CGY-5, silicone oil DC-193, silicone oil SC-154 and silicone oil SC-155.

In the invention, the isocyanate compound is one or more of diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate and toluene diisocyanate. In the present invention, the diphenylmethane diisocyanate (MDI) is preferably one of MDI-100LL, MDI-100HL, MR-200, M200, 44V20, M20S and 5005, the polyphenyl polymethylene polyisocyanate (PAPI) is preferably PAPI-27, and the Toluene Diisocyanate (TDI) is preferably 2, 4-toluene diisocyanate and 2, 6-toluene diisocyanate.

In the invention, the mass ratio of the degradation product to the chain extender, the foaming agent, the catalyst and the foam stabilizer is preferably 20-50: 1-8: 4-20: 1-8: 2-10, and more preferably 30-40: 3-5: 8-15: 3-5: 5-8; the mass ratio of the degradation product to the isocyanate compound is preferably 30: 30-225, more preferably 30: 50-200, and further preferably 30: 80-150. The invention does not require any particular mixing means, such as stirring, known to the person skilled in the art. In the invention, the foaming temperature is preferably 160-250 ℃, more preferably 180-220 ℃, the time is preferably 0.5-2.5 h, more preferably 1-2 h, and the pressure is preferably 0.1-0.3 MPa, more preferably 0.2 MPa.

The graphene oxide/fly ash modified recycled polyurethane composite and the preparation method thereof provided by the present invention are described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.

Example 1

(1) Drying 1g of fly ash at 60 ℃ for 24h, acidifying for 30min by using 0.4mol/L hydrochloric acid, adding 100g of ethanol solution with the volume concentration of 95% and 4gKH-550 silane coupling agent, carrying out ultrasonic treatment at 100W for 2h, washing by using deionized water, carrying out suction filtration, and drying the obtained solid for 24h to obtain the acidified fly ash.

(2) Adding the acidified fly ash and 1g of graphene oxide into 50g of dimethylformamide solvent, performing ultrasonic treatment for 2h at 100W, stirring for 10min in a water bath kettle at 100 ℃, cleaning with absolute ethyl alcohol, filtering, and drying the obtained powder for 24h at 60 ℃ in vacuum to obtain the graphene oxide/fly ash cross-linked hybrid.

(3) Adding 50g of propylene glycol and 10g of potassium hydroxide into 120g of cleaned and dried waste polyurethane foam for 10 hours to prepare degraded alcoholic solution, then adding graphene oxide/fly ash cross-linked hybrid, wherein the mass ratio of the waste polyurethane foam to the graphene oxide/fly ash cross-linked hybrid is 10:1, mechanically stirring for 3 hours at 100 ℃, and ultrasonically dispersing for 2 hours to obtain a recyclable degradation product.

(4) And (3) uniformly stirring 30g of degradation product, 1g of triethanolamine, 1g of stannous octoate and 2g of silicone oil, stirring with 34g of PAPI-27 after 100W of ultrasonic dispersion is carried out for 30min, foaming for 1h at 160 ℃ and 0.1MPa, and cooling to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

The scanning electron microscope image of the fly ash is shown in fig. 1, and the scanning electron microscope image of the obtained graphene oxide/fly ash cross-linked hybrid is shown in fig. 2. As can be seen from fig. 1 and 2, the graphene oxide was successfully crosslinked with the fly ash.

The infrared picture of the fly ash is shown in fig. 3, and the infrared picture of the graphene oxide/fly ash modified recycled polyurethane composite material is shown in fig. 4. As can be seen from fig. 3 and 4, the resulting composite material contains toner ash.

Example 2

(1) A graphene oxide/fly ash cross-linked hybrid was prepared in the manner of example 1.

(2) Adding 50g of butanediol and 10g of potassium hydroxide into 120g of cleaned and dried waste polyurethane foam for 10 hours to prepare degraded alcoholysis solution, then adding oxidized graphene/fly ash cross-linked hybrid, wherein the mass ratio of the waste polyurethane foam to the oxidized graphene/fly ash cross-linked hybrid is 5:1, mechanically stirring for 5 hours at 110 ℃, and ultrasonically dispersing for 1 hour to obtain a recyclable degradation product.

(3) And (3) uniformly stirring 30g of degradation product, 2g of triethanolamine, 2g of stannous octoate and 3g of silicone oil, stirring with 37g of PAPI-27 after ultrasonic dispersion is carried out for 30min at 200W, foaming for 1.5h at 180 ℃ and 0.1MPa, and cooling to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

Example 3

(1) A graphene oxide/fly ash cross-linked hybrid was prepared in the manner of example 1.

(2) Adding 60g of propylene glycol and 12g of triethanolamine into 120g of cleaned and dried waste polyurethane foam for 10 hours to prepare degraded alcoholic solution, then adding graphene oxide/fly ash cross-linked hybrid with the mass ratio of 10:3, mechanically stirring for 6 hours at 120 ℃, and ultrasonically dispersing for 2 hours to obtain a recyclable degraded product.

(3) And (3) uniformly stirring 30g of degradation product, 3g of triethanolamine, 3g of stannous octoate and 4g of silicone oil, stirring with 37g of PAPI-27 after ultrasonic dispersion is carried out for 30min at 200W, foaming for 2.5h at 200 ℃ and 0.1MPa, and cooling to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

Example 4

(1) A graphene oxide/fly ash cross-linked hybrid was prepared in the manner of example 1.

(2) Adding 70g of butanediol and 13g of triethanolamine into 120g of cleaned and dried waste polyurethane foam for 10 hours to prepare degraded alcoholic solution, then adding graphene oxide/fly ash cross-linked hybrid, mechanically stirring the waste polyurethane foam and the graphene oxide/fly ash cross-linked hybrid at 105 ℃ for 4 hours, and ultrasonically dispersing for 2 hours to obtain a recyclable degraded product.

(3) And (3) uniformly stirring 30g of degradation product, 4g of triethanolamine, 4g of stannous octoate and 6g of silicone oil, stirring with 44g of PAPI-27 after ultrasonic dispersion is carried out for 30min at 200W, foaming for 2h at 170 ℃ and 0.1MPa, and cooling to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

Example 5

(1) A graphene oxide/fly ash cross-linked hybrid was prepared in the manner of example 1.

(2) Adding 50g of butanediol and 10g of magnesium hydroxide into 120g of cleaned and dried waste polyurethane foam for 10 hours to prepare degraded alcoholysis solution, then adding a graphene oxide/fly ash cross-linked hybrid, wherein the mass ratio of the waste polyurethane foam to the graphene oxide/fly ash cross-linked hybrid is 2:1, mechanically stirring for 4 hours at 115 ℃, and ultrasonically dispersing for 2 hours to obtain a recyclable degradation product.

(3) And (3) uniformly stirring 30g of degradation product, 4g of triethanolamine, 7g of stannous octoate and 10g of silicone oil, stirring with 51g of PAPI-27 after ultrasonic dispersion is carried out for 30min at 200W, foaming for 2h at 220 ℃ and 0.1MPa, and cooling to obtain the graphene oxide/fly ash modified regenerated polyurethane composite material.

Comparative example 1

Comparative example 1 differs from example 1 in that no graphene oxide/fly ash cross-linked hybrid was added to give a recycled polyurethane material.

Comparative example 2

The comparative example 2 is different from the example 1 in that the graphene oxide/fly ash cross-linked hybrid is replaced by the same amount of graphene oxide to obtain a graphene oxide modified recycled polyurethane composite, and the performance of the obtained composite is tested.

Comparative example 3

The difference between the comparative example 3 and the example 1 is that the graphene oxide/fly ash cross-linked hybrid is replaced by the same amount of fly ash to obtain the fly ash modified recycled polyurethane composite material, and the performance of the obtained composite material is tested.

Comparative example 4

The difference between the comparative example 4 and the example 1 is that the graphene oxide/fly ash cross-linked hybrid is replaced by the same amount of the mixture of the uncrosslinked fly ash and the graphene oxide to obtain the fly ash and graphene oxide modified regenerated polyurethane composite material, and the performance of the obtained composite material is tested.

Performance testing

The compression strength and the thermal conductivity of the recycled polyurethane materials obtained in examples 1 to 5 and comparative examples 1 to 4 were tested, and the obtained results are favorable to table 1. Wherein the test standard of the compressive strength refers to GBT8813-2008 standard for measuring the compressive property of rigid foam, and the test standard of the thermal conductivity refers to GBT21558-2008 standard for rigid polyurethane foam for building thermal insulation.

TABLE 1 Properties of the recycled polyurethane materials obtained in examples 1 to 5 and comparative examples 1 to 4

As can be seen from Table 1, the graphene oxide/fly ash modified recycled polyurethane composite material provided by the invention has good compressive strength and a low thermal conductivity coefficient.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.