1. A preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material is characterized by comprising the following steps:

firstly, weighing the following raw materials in parts by weight:

white materials: 100 portions of polyether polyol, 100 portions of polyester polyol and 0.1 portion to 0.2 portion of catalyst;

18-30 parts of flame-retardant filler, 1-2.5 parts of flame retardant and 16-20 parts of foaming agent;

secondly, uniformly dispersing the flame-retardant filler and the flame retardant, adding a white material, stirring and mixing for 1h, adding a foaming agent, stirring for 0.5h, adding a black material, uniformly mixing by a foaming machine, and carrying out a foaming reaction to obtain the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material;

the flame-retardant filler is prepared by the following steps:

mixing ethyl orthosilicate, flame retardant components and ethanol, adding a hydrochloric acid solution and hexadecyl trimethyl ammonium bromide, magnetically stirring for 30min, and standing for 24h at room temperature; then dropwise adding ammonia water, stirring for 30min, aging for 2 days by using an ethanol water solution with the volume fraction of 80% and the same volume, then performing ethanol and n-hexane replacement at 50 ℃, and drying under normal pressure to obtain the flame-retardant filler.

2. The preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material according to claim 1, wherein the flame-retardant component is prepared by the following steps:

step S11, mixing 2-hydroxyethyl acrylate, dichloromethane and triethylamine, stirring and cooling to 0 ℃ under the protection of nitrogen, slowly dripping a dichloromethane solution of diphenyl chlorophosphate, keeping the temperature unchanged after dripping is finished, continuously stirring for reacting for 24 hours, and performing post-treatment after the reaction is finished; obtaining an intermediate 1;

step S12, mixing the intermediate 1 and toluene, heating to 50 ℃ under the protection of nitrogen, adding a Kaster catalyst, continuously stirring for reacting for 60min, then dropwise adding triethoxysilane, heating to 70 ℃ after dropwise adding, reacting for 24h, and performing post-treatment after the reaction is finished; obtaining the flame-retardant component.

3. The method for preparing the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material according to claim 2, wherein the dosage ratio of the dichloromethane solution of hydroxyethyl 2-acrylate, dichloromethane, triethylamine and diphenyl chlorophosphate in step S11 is 1.2 g: 10mL of: 2.1 g: 30mL of a solution of diphenyl chlorophosphate in methylene chloride, wherein the solution of diphenyl chlorophosphate in methylene chloride is a mixture of diphenyl chlorophosphate and methylene chloride in an amount of 1 g: 10mL of the mixture is mixed; in the step S12, the using amount ratio of the intermediate 1, the toluene, the Kaster catalyst and the triethoxysilane is 3.5 g: 100mL of: 0.2 mL: 1.7 g.

4. The preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material according to claim 1, wherein the concentration of the hydrochloric acid solution is 1 mol/L; the mass fraction of the ammonia water is 25 percent; the dosage mass ratio of the ethyl orthosilicate to the flame retardant component is 1: 0.5-0.6; the dosage ratio of the ethyl orthosilicate, the ethanol, the hydrochloric acid solution, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1 g: 20mL of: 0.6 g: 0.3 g: 0.5 g.

5. The preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material according to claim 1, wherein the black material is isocyanate; the mass ratio of the white material to the black material is 1: 1.1-1.2.

6. The method for preparing the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material according to claim 1, wherein the catalyst is one or more of dimethylcyclohexylamine, triethylene diamine and triethanolamine; the foaming agent is methyl formate; the flame retardant is dimethyl methyl phosphate.

Background

The polyurethane rigid foam plastic has the advantages of low heat conductivity coefficient, excellent mechanical property, aging resistance, chemical resistance and the like, and is widely used as heat insulation materials of buildings, heat transmission pipelines and the like. The proportion of carbon and hydrogen in a polyurethane molecular chain is high, and the polyurethane belongs to flammable high polymer materials; and the polyurethane foam has small density and large specific surface area, and can be fully contacted with oxygen during combustion to accelerate the combustion of the foam. Therefore, the polyurethane foam has a low limiting oxygen index of 16 to 18%, is a flammable material, and releases a large amount of toxic fumes when burned. The use of flammable polyurethane insulation materials would present a serious fire hazard.

The flame-retardant polyurethane foam plastic mainly adopts blended metal oxide and brominated flame retardant, but halogen has the problem of environmental pollution.

Disclosure of Invention

The invention provides a preparation method of a heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material comprises the following steps:

firstly, weighing the following raw materials in parts by weight:

white materials: 100 portions of polyether polyol, 100 portions of polyester polyol and 0.1 portion to 0.2 portion of catalyst;

18-30 parts of flame-retardant filler, 1-2.5 parts of flame retardant and 16-20 parts of foaming agent;

and secondly, uniformly dispersing the flame-retardant filler and the flame retardant, adding the white material, stirring and mixing for 1h, adding the foaming agent, stirring for 0.5h, adding the black material, uniformly mixing by a foaming machine, and carrying out foaming reaction to obtain the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material.

The flame-retardant filler is prepared by the following steps:

mixing ethyl orthosilicate, flame retardant components and ethanol, adding a hydrochloric acid solution and hexadecyl trimethyl ammonium bromide, magnetically stirring for 30min, and standing for 24h at room temperature; then dropwise adding ammonia water, stirring for 30min, aging for 2 days by using an ethanol water solution with the volume fraction of 80% and the same volume, then performing ethanol and n-hexane displacement at the temperature of 50 ℃, and drying under normal pressure to obtain the flame-retardant filler.

Further, the flame retardant component is prepared by the following steps:

step S11, mixing 2-hydroxyethyl acrylate, dichloromethane and triethylamine, stirring and cooling to 0 ℃ under the protection of nitrogen, slowly dripping a dichloromethane solution of diphenyl chlorophosphate, keeping the temperature unchanged after dripping is finished, continuously stirring for reacting for 24 hours, and performing post-treatment after the reaction is finished; the post-treatment process comprises the following steps: washing the obtained reaction solution with deionized water, a sodium hydroxide solution with the mass fraction of 5% and deionized water in sequence, drying the obtained organic phase with anhydrous sodium sulfate after washing, and performing rotary evaporation to remove the solvent after drying to obtain an intermediate 1;

the reaction process is as follows:

step S12, mixing the intermediate 1 and toluene, heating to 50 ℃ under the protection of nitrogen, adding a Kaster catalyst, continuously stirring for reacting for 60min, then dropwise adding triethoxysilane, heating to 70 ℃ after dropwise adding, reacting for 24h, and performing post-treatment after the reaction is finished; the post-treatment process comprises the following steps: filtering the obtained reaction solution while the reaction solution is hot, cooling to room temperature, concentrating under reduced pressure to remove the solvent, and then recrystallizing with ethanol to obtain the flame-retardant component.

The reaction process is as follows:

further, the amount ratio of the dichloromethane solution of hydroxyethyl 2-acrylate, dichloromethane, triethylamine and diphenyl chlorophosphate in the step S11 was 1.2 g: 10mL of: 2.1 g: 30mL of a solution of diphenyl chlorophosphate in methylene chloride, wherein the solution of diphenyl chlorophosphate in methylene chloride is a mixture of diphenyl chlorophosphate and methylene chloride in an amount of 1 g: 10mL of the mixture is mixed; in the step S12, the using amount ratio of the intermediate 1, the toluene, the Kaster catalyst and the triethoxysilane is 3.5 g: 100mL of: 0.2 mL: 1.7 g.

Further, the concentration of the hydrochloric acid solution is 1 mol/L; the mass fraction of the ammonia water is 25 percent; the dosage mass ratio of the ethyl orthosilicate to the flame retardant component is 1: 0.5-0.6; the dosage ratio of the ethyl orthosilicate, the ethanol, the hydrochloric acid solution, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1 g: 20mL of: 0.6 g: 0.3 g: 0.5 g.

Further, the black material is isocyanate; the mass ratio of the white material to the black material is 1: 1.1-1.2.

Further, the catalyst is one or more of dimethylcyclohexylamine, triethylene diamine and triethanolamine; the foaming agent is methyl formate; the flame retardant is dimethyl methyl phosphate.

The invention has the beneficial effects that:

the flame-retardant filler is modified silicon dioxide aerogel, the prepared flame-retardant component and tetraethoxysilane are used as a composite silicon source to prepare the prepared silicon dioxide aerogel, the flame-retardant component is a phosphorus-containing monomer, the phosphorus-containing monomer is introduced into the prepared flame-retardant filler, phosphorus oxygen free radicals can be generated in the pyrolysis process, the combustion reaction can be stopped by combining active H & OH & free radicals in flame, the carbonization of the material is promoted, the prepared flame-retardant filler is introduced into a rigid polyurethane foam matrix, and the heat insulation performance and the flame retardant performance of the silicon aerogel and the synergistic flame retardant effect of the silicon aerogel and dimethyl methylphosphonate are utilized to prepare the heat-insulation flame-retardant polyurethane-silicon aerogel composite heat insulation material; the problem of halogen environmental pollution caused by the fact that the flame-retardant polyurethane foam plastic mainly adopts blended metal oxide and brominated flame retardant is solved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Preparing a flame-retardant component:

step S11, mixing 2-hydroxyethyl acrylate, dichloromethane and triethylamine, stirring and cooling to 0 ℃ under the protection of nitrogen, slowly dripping a dichloromethane solution of diphenyl chlorophosphate, keeping the temperature unchanged after dripping is finished, continuously stirring for reacting for 24 hours, and performing post-treatment after the reaction is finished; the post-treatment process comprises the following steps: washing the obtained reaction solution with deionized water, a sodium hydroxide solution with the mass fraction of 5% and deionized water in sequence, drying the obtained organic phase with anhydrous sodium sulfate after washing, and performing rotary evaporation to remove the solvent after drying to obtain an intermediate 1;

step S12, mixing the intermediate 1 and toluene, heating to 50 ℃ under the protection of nitrogen, adding a Kaster catalyst, continuously stirring for reacting for 60min, then dropwise adding triethoxysilane, heating to 70 ℃ after dropwise adding, reacting for 24h, and performing post-treatment after the reaction is finished; the post-treatment process comprises the following steps: filtering the obtained reaction solution while the reaction solution is hot, cooling to room temperature, concentrating under reduced pressure to remove the solvent, and then recrystallizing with ethanol to obtain the flame-retardant component.

Wherein the dosage ratio of the dichloromethane solution of hydroxyethyl 2-acrylate, dichloromethane, triethylamine and diphenyl chlorophosphate in the step S11 is 1.2 g: 10mL of: 2.1 g: 30mL of a solution of diphenyl chlorophosphate in methylene chloride, wherein the solution of diphenyl chlorophosphate in methylene chloride is a mixture of diphenyl chlorophosphate and methylene chloride in an amount of 1 g: 10mL of the mixture is mixed; in the step S12, the using amount ratio of the intermediate 1, the toluene, the Kaster catalyst and the triethoxysilane is 3.5 g: 100mL of: 0.2 mL: 1.7 g.

Example 2

Preparing a flame-retardant filler:

mixing ethyl orthosilicate, flame retardant components and ethanol, adding a hydrochloric acid solution and hexadecyl trimethyl ammonium bromide, magnetically stirring for 30min, and standing for 24h at room temperature; then dropwise adding ammonia water, stirring for 30min, aging for 2 days by using an ethanol water solution with the volume fraction of 80% and the same volume, then performing ethanol and n-hexane displacement at the temperature of 50 ℃, and drying under normal pressure to obtain the flame-retardant filler.

Wherein the concentration of the hydrochloric acid solution is 1 mol/L; the mass fraction of the ammonia water is 25 percent; the dosage mass ratio of the ethyl orthosilicate to the flame retardant component is 1: 0.5; the dosage ratio of the ethyl orthosilicate, the ethanol, the hydrochloric acid solution, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1 g: 20mL of: 0.6 g: 0.3 g: 0.5g of flame retardant component was obtained as in example 1.

Example 3

Mixing ethyl orthosilicate, flame retardant components and ethanol, adding a hydrochloric acid solution and hexadecyl trimethyl ammonium bromide, magnetically stirring for 30min, and standing for 24h at room temperature; then dropwise adding ammonia water, stirring for 30min, aging for 2 days by using an ethanol water solution with the volume fraction of 80% and the same volume, then performing ethanol and n-hexane displacement at the temperature of 50 ℃, and drying under normal pressure to obtain the flame-retardant filler.

Wherein the concentration of the hydrochloric acid solution is 1 mol/L; the mass fraction of the ammonia water is 25 percent; the dosage mass ratio of the ethyl orthosilicate to the flame retardant component is 1: 0.6; the dosage ratio of the ethyl orthosilicate, the ethanol, the hydrochloric acid solution, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1 g: 20mL of: 0.6 g: 0.3 g: 0.5g of flame retardant component was obtained as in example 1.

Example 4

A preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material comprises the following steps:

firstly, weighing the following raw materials in parts by weight:

white materials: 100 parts of polyether polyol, 100 parts of polyester polyol and 0.1 part of catalyst;

18 parts of flame-retardant filler, 1 part of flame retardant and 16 parts of foaming agent;

and secondly, uniformly dispersing the flame-retardant filler and the flame retardant, adding the white material, stirring and mixing for 1h, adding the foaming agent, stirring for 0.5h, adding the black material, uniformly mixing by a foaming machine, and carrying out foaming reaction to obtain the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material.

Wherein the black material is isocyanate; the mass ratio of the white material to the black material is 1: 1.1. the catalyst is dimethyl cyclohexylamine; the foaming agent is methyl formate; the flame retardant is dimethyl methyl phosphate. The flame retardant filler was prepared as in example 3.

Example 5

A preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material comprises the following steps:

firstly, weighing the following raw materials in parts by weight:

white materials: 110 parts of polyether polyol, 110 parts of polyester polyol and 0.1 part of catalyst;

22 parts of flame-retardant filler, 1.5 parts of flame retardant and 18 parts of foaming agent;

and secondly, uniformly dispersing the flame-retardant filler and the flame retardant, adding the white material, stirring and mixing for 1h, adding the foaming agent, stirring for 0.5h, adding the black material, uniformly mixing by a foaming machine, and carrying out foaming reaction to obtain the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material.

Wherein the black material is isocyanate; the mass ratio of the white material to the black material is 1: 1.1. the catalyst is triethylene diamine; the foaming agent is methyl formate; the flame retardant is dimethyl methyl phosphate. The flame retardant filler was prepared as in example 3.

Example 6

A preparation method of the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material comprises the following steps:

firstly, weighing the following raw materials in parts by weight:

white materials: 120 parts of polyether polyol, 120 parts of polyester polyol and 0.2 part of catalyst;

30 parts of flame-retardant filler, 2.5 parts of flame retardant and 20 parts of foaming agent;

and secondly, uniformly dispersing the flame-retardant filler and the flame retardant, adding the white material, stirring and mixing for 1h, adding the foaming agent, stirring for 0.5h, adding the black material, uniformly mixing by a foaming machine, and carrying out foaming reaction to obtain the heat-insulating flame-retardant polyurethane-silicon aerogel composite heat-insulating material.

Wherein the black material is isocyanate; the mass ratio of the white material to the black material is 1: 1.2. the catalyst is triethanolamine; the foaming agent is methyl formate; the flame retardant is dimethyl methyl phosphate. The flame retardant filler was prepared as in example 3.

Comparative example 1

Sample a was prepared without the flame retardant component of example 3; the flame retardant filler of example 5 was changed to sample a, and the remaining raw materials and preparation process were kept unchanged.

The heat insulating materials prepared in the examples 4-6 and the comparative example are subjected to performance tests, the heat conducting performance is determined according to the specification of GB/T10294-2008, and the water absorption is determined according to the specification of GB/T8810-2005; determining the flame retardant grade according to the standard GB 8624-97; the apparent density and dimensional stability of the insulation material were tested according to GB/T6343-1995 and GB/T8811-2008;

the test results are shown in table 1 below;

TABLE 1

Item	Example 4	Example 5	Example 6	Comparative example 1
					Thermal conductivity (W/(m.k))	0.021	0.021	0.021	0.030
Water absorption (%)	1.2	1.2	1.25	2.5
					Flame retardant rating	A	A	A	B1
Apparent density (kg/m)3)	42	42	42	45
					Dimensional stability (%)	0.3	0.3	0.3	0.5

The heat insulation material prepared by the invention has lower heat conductivity coefficient and good flame retardant effect; under the condition of achieving the same heat preservation and insulation effect, the used heat preservation layer is smaller in thickness, and the requirements of users are met.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.