Polystyrene thermal insulation material and preparation method thereof

Abstract

The invention discloses a polystyrene thermal insulation material and a preparation method thereof, and belongs to the technical field of construction.The preparation method comprises the steps that polystyrene hollow glass bead composite particles and a foaming agent are pre-foamed, and pre-foamed particles are obtained; the preparation method comprises the following steps: mixing polyisocyanate and polyol in a mass ratio of (1.4-1.6): 1 to obtain a binder; and mixing the pre-foamed particles, a binder and polysiloxane borane, and carrying out expansion foaming to obtain the polystyrene thermal insulation material. According to the invention, the pre-foaming treatment can make polystyrene hollow glass bead composite particles generate no tiny hollow bodies, the polystyrene hollow glass bead composite particles reach a secondary foaming stage through curing for a certain time, and a binder containing a flame retardant is mixed with the pre-foaming particles and polyborosilazane to prepare the flame-retardant polystyrene hollow glass bead composite material. The binder and the polyborosilazane can better coat the surfaces of the pre-foamed polystyrene hollow glass bead composite particles, so that the dispersion uniformity of the raw materials is improved, and the flame retardant property and the mechanical property of the thermal insulation material are further improved.

Description

A polystyrene thermal insulation material and its preparation method Technical Field

[0001] This invention belongs to the field of building technology, specifically relating to a polystyrene thermal insulation material and its preparation method. Background Technology

[0002] Polystyrene insulation materials are widely used in construction, light industry and shipping due to their excellent properties such as light weight, insulation, heat insulation, shock resistance, sound insulation, corrosion resistance, water resistance and chemical stability.

[0003] Polystyrene, the main raw material of polystyrene insulation materials, is a flammable polymer material with a low limiting oxygen index. It is easy to burn rapidly when exposed to fire, and when burning, it easily produces molten drips with open flames, which can ignite other flammable materials, exacerbate the spread of fire, and cause serious fire safety hazards. Even if the fire source is removed, it can continue to burn. Therefore, it is prone to fire during stacking and construction.

[0004] Therefore, flame-retardant treatment is needed to improve the flame-retardant properties of polystyrene insulation boards. To enhance these properties, modification with flame retardants is commonly employed. Currently used flame-retardant systems include halogen-based, phosphorus-based, intumescent, and inorganic flame retardants. Inorganic flame retardants, such as aluminum hydroxide and magnesium hydroxide, are environmentally friendly, but the required filler quantity to achieve an effective flame-retardant rating is very large, which significantly deteriorates the material's processability, density, and mechanical strength.

[0005] Improving the flame retardant properties of polystyrene often results in a significant decrease in its key mechanical properties (such as tensile strength, compressive strength, and toughness), affecting its long-term reliable application in fields such as construction. How to achieve good flame retardant effects while maintaining or improving the material's overall mechanical properties has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a polystyrene insulation material and its preparation method, so as to solve the problem of poor flame retardant properties of polystyrene insulation materials.

[0007] The objective of this invention can be achieved through the following technical solution: The first aspect of this invention provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.1-0.3 MPa and a temperature of 70-90°C to obtain pre-foamed particles; mixing a polyisocyanate and a polyol component in a mass ratio of 1.4-1.6:1 to obtain a binder; the polyol component includes a polyol, a catalyst, and a flame retardant; mixing the pre-foamed particles, the binder, and polysiloxane, and expanding and foaming under a pressure of 0.2-1.0 MPa and a temperature of 115-130°C to obtain the polystyrene insulation material.

[0008] In some possible implementations, the mass ratio of polystyrene hollow glass microsphere composite particles, foaming agent, binder and polysiloxane is 100:6-10:10-20:5-8.

[0009] In some possible implementations, the mass ratio of polyol, catalyst, and flame retardant is 100:3.3:35.

[0010] In some possible implementations, the polyol is at least one of polyester polyol and polyether polyol.

[0011] In some possible implementations, the foaming agent is pentane, which can be either n-pentane or isopentane; the catalyst is 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate and potassium acetate in a mass ratio of 1:3; the flame retardant is tris(2-chloropropyl) phosphate; the polyisocyanate is polymethylene polyphenyl polyisocyanate; and the mass ratio of polyester polyol to polyether polyol is 1:1-2.

[0012] In some possible implementations, polystyrene hollow glass microsphere composite particles are prepared through the following steps: Aqueous phase mixtures are obtained by mixing water, tricalcium phosphate, and polyvinyl alcohol, adjusting the pH to 7-8; styrene, benzoyl peroxide, tributyl phosphate, and hydrophobically treated hollow glass microspheres are mixed to obtain an oil phase mixture; the oil phase mixture is added dropwise to the aqueous phase mixture; and the mixture is stirred and reacted at 85-90℃ for 3-4 hours to obtain polystyrene hollow glass microsphere composite particles. This invention uses a suspension polymerization process to prepare expandable core-shell composite particles with hollow glass microspheres as the "core" and polystyrene as the "shell." Hollow glass microspheres possess characteristics such as high compressive strength, high melting point, high resistivity, low thermal conductivity, and low coefficient of thermal shrinkage. Using hollow glass microspheres as the "core" can improve the thermal insulation performance of polystyrene insulation materials.

[0013] In some possible implementations, the aqueous phase mixture contains 2% tricalcium phosphate and 4% polyvinyl alcohol by mass. The ratio of styrene, benzoyl peroxide, tributyl phosphate, and hydrophobically treated hollow glass microspheres in the oil phase mixture is 100 mL: 1 g: 3 g: 2-4 g. The ratio of the aqueous phase mixture to the oil phase mixture is 2:1 by mass.

[0014] In some possible implementations, the particle size of the hollow glass microspheres is 80-100 μm; the hydrophobic treatment is performed on the hollow glass microspheres treated with vinylsiloxane, which includes the following steps: γ-methacryloyloxypropyltrimethoxysilane, ethanol and water are mixed at a ratio of 10 g: 80 mL: 20 mL, and the mixture is added to the hollow glass microspheres at a solid-liquid ratio of 1 g: 4 mL. After dispersion, the mixture is refluxed at 80 °C for 2-3 h, and after solid-liquid separation and drying, the hollow glass microspheres treated with vinylsiloxane are obtained.

[0015] In some possible implementations, polyborosiloxane is prepared by the following steps: adding a silane coupling agent and tetraethyl orthosilicate to a solvent and stirring to obtain a silane dilution; adding phenylboronic acid to a solvent and stirring to obtain a phenylboronic acid dilution; adding the silane dilution dropwise to the phenylboronic acid dilution; after the addition is complete, heating to 70-80℃ and reacting for 8-9 hours; after the reaction is complete, removing the solvent by rotary evaporation to obtain polyborosiloxane.

[0016] In some possible implementations, the ratio of silane coupling agent, tetraethyl orthosilicate, and phenylboronic acid is 0.1 mol: 0.4-0.6 mol: 0.1 mol, and the ratio of solvent to reactants is 1 g: 10-15 mL. For example, the ratio of phenylboronic acid to solvent is 1 g: 10-15 mL, the ratio of tetraethyl orthosilicate to solvent is 1 g: 10-15 mL, and the ratio of silane coupling agent to solvent is 1 g: 10-15 mL.

[0017] In some possible implementations, the silane coupling agent is one of vinylsiloxane or epoxysiloxane; wherein the vinylsiloxane is one of γ-methacryloxypropyltrimethoxysilane, 7-octenyltrimethoxysilane, and vinyltrimethoxysilane; and the epoxysiloxane is γ-glycidoxypropyltrimethoxysilane. 7-octenyltrimethoxysilane can introduce hydrophobic long chains, further improving the freeze-thaw resistance of the insulation material. The introduction of γ-glycidoxypropyltrimethoxysilane increases the crosslinking density, leading to greater brittleness of the material and hindering further improvement in the freeze-thaw resistance of the insulation material.

[0018] This invention improves the freeze-thaw cycle resistance of polystyrene insulation materials by combining polyborosiloxane with polystyrene and utilizing the characteristics of the polyborosiloxane BO-Si main chain, such as good low-temperature toughness, low glass transition temperature, and reversible dynamic borate ester bonds.

[0019] Polyborosiloxane can be rapidly ceramicized at high temperatures to form a continuous Si-OB glassy protective layer that isolates oxygen and heat. In the process of improving the flame retardancy of polystyrene insulation materials, the boron element in polyborosiloxane can also promote the cross-linking of polystyrene into char, inhibit molten dripping, and further enhance the flame retardant effect.

[0020] However, the polarity difference between polyborosiloxane and polystyrene increases, affecting their compatibility. To improve the compatibility between polyborosiloxane and polystyrene, this invention selects phenylboronic acid as the raw material for preparing polyborosiloxane, eliminating the need for additional compatibilizers. This improves the mechanical and thermal insulation properties of polystyrene insulation materials while ensuring enhanced freeze-thaw cycle resistance.

[0021] A second aspect of the present invention provides a polystyrene thermal insulation material, which is prepared by the above method.

[0022] The beneficial effects of this invention are as follows: This invention pre-foams polystyrene hollow glass microsphere composite particles, causing the polystyrene hollow glass microsphere composite particles to produce numerous tiny hollow bodies. After a certain period of curing, they reach the secondary foaming stage. Then, a binder containing flame retardant is mixed with the pre-foamed polystyrene hollow glass microsphere composite particles, so that the binder and polysiloxane can better coat the surface of the pre-foamed polystyrene hollow glass microsphere composite particles, improving the dispersion uniformity and further enhancing the flame retardant and mechanical properties. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] The following is a detailed description of a polystyrene thermal insulation material and its preparation method according to an embodiment of this application.

[0025] The following is a detailed description with reference to specific examples.

[0026] Example 1

[0027] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.1 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.5:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.2 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles, foaming agent, binder, and polysiloxane is 100:8:15:8; the polyol component includes polyol, catalyst, and flame retardant; the mass ratio of polyol, catalyst, and flame retardant is 100:3.3:35. The catalyst is 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate and potassium acetate in a mass ratio of 1:3; the flame retardant is tris(2-chloropropyl) phosphate; the polyester polyol has a hydroxyl value of 250~270 mgKOH / g and is manufactured by Jinan Meiyu New Materials Co., Ltd.; the polyether polyol has f=3 and a hydroxyl value of 160~170 mgKOH / g and is manufactured by Shandong Yinuowei New Materials Co., Ltd.; the polyisocyanate is polymethylene polyphenyl polyisocyanate; the mass ratio of polyester polyol to polyether polyol is 1:1.

[0028] The above-mentioned polystyrene hollow glass microsphere composite particles were prepared by the following steps: γ-methacryloyloxypropyltrimethoxysilane, ethanol and water were mixed at a ratio of 10g:80mL:20mL, and hollow glass microspheres were added at a solid-liquid ratio of 1g:4mL. After dispersion, the mixture was refluxed at 80℃ for 2h. After solid-liquid separation and drying, hollow glass microspheres treated with vinylsiloxane were obtained. The hollow glass microspheres have a particle size of 80-100 μm. Aqueous phase mixtures are obtained by mixing water, tricalcium phosphate, and polyvinyl alcohol, and adjusting the pH to 7. Oil phase mixtures are obtained by mixing styrene, benzoyl peroxide, tributyl phosphate, and hydrophobically treated hollow glass microspheres. The oil phase mixture is added dropwise to the aqueous phase mixture, and the mixture is stirred at 90℃ for 3 hours to obtain polystyrene hollow glass microsphere composite particles. The mass fraction of tricalcium phosphate in the aqueous phase mixture is 2%, and the mass fraction of polyvinyl alcohol is 4%. The ratio of styrene, benzoyl peroxide, tributyl phosphate, and vinylsiloxane-treated hollow glass microspheres in the oil phase mixture is 100 mL: 1 g: 3 g: 3 g. The mass ratio of the aqueous phase mixture to the oil phase mixture is 2:1.

[0029] The above-mentioned polyborosiloxane was prepared by the following steps: A silane coupling agent and tetraethyl orthosilicate were added to 1,2-dichloroethane and stirred to obtain a diluted silane solution. Benzylboronic acid was added to 1,2-dichloroethane and stirred to obtain a diluted phenylboronic acid solution. The diluted silane solution was then added dropwise to the diluted phenylboronic acid solution. After the addition was complete, the temperature was raised to 80°C, and the reaction was carried out for 8 hours. After the reaction was completed, 1,2-dichloroethane was removed by rotary evaporation to obtain the polyborosiloxane. The molar ratio of silane coupling agent, tetraethyl orthosilicate, and phenylboronic acid was 0.1 mol: 0.5 mol: 0.1 mol. The silane coupling agent was γ-methacryloyloxypropyltrimethoxysilane.

[0030] Example 2

[0031] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.2 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.5:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.3 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles to foaming agent, binder, and polysiloxane is 100:8:20:5; the remaining raw materials and preparation process are the same as in Example 1.

[0032] Example 3

[0033] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.2 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.4:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.3 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles and foaming agent, binder, and polysiloxane is 100:8:10:8; the remaining raw materials and preparation process are the same as in Example 1.

[0034] Example 4

[0035] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.2 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.6:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.3 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles and foaming agent, binder, and polysiloxane is 100:8:20:8; the remaining raw materials and preparation process are the same as in Example 1.

[0036] Example 5

[0037] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.1 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.5:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.2 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles and foaming agent, binder, and polysiloxane is 100:8:15:8; the remaining raw materials and preparation process are the same as in Example 1.

[0038] The above-mentioned polystyrene hollow glass microsphere composite particles are the same as those in Example 1.

[0039] The above-mentioned polyborosiloxane was prepared by the following steps: A silane coupling agent and tetraethyl orthosilicate were added to 1,2-dichloroethane and stirred to obtain a diluted silane solution. Benzylboronic acid was added to 1,2-dichloroethane and stirred to obtain a diluted phenylboronic acid solution. The diluted silane solution was added dropwise to the diluted phenylboronic acid solution. After the addition was complete, the temperature was raised to 80°C and the reaction was carried out for 8 hours. After the reaction was completed, 1,2-dichloroethane was removed by rotary evaporation to obtain the polyborosiloxane. The molar ratio of silane coupling agent, tetraethyl orthosilicate, and phenylboronic acid was 0.1 mol: 0.5 mol: 0.1 mol. The silane coupling agent was 7-octenyltrimethoxysilane.

[0040] Example 6

[0041] This embodiment provides a method for preparing polystyrene insulation material, comprising the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.1 MPa and a temperature of 80°C to obtain pre-foamed particles; the foaming agent is pentane; mixing polyisocyanate and polyol components in a mass ratio of 1.5:1 to obtain a binder; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming under a pressure of 0.2 MPa and a temperature of 120°C to obtain polystyrene insulation material; wherein the mass ratio of polystyrene hollow glass microsphere composite particles and foaming agent, binder, and polysiloxane is 100:8:15:8; the remaining raw materials and preparation process are the same as in Example 1.

[0042] The above-mentioned polystyrene hollow glass microsphere composite particles are the same as those in Example 1.

[0043] The above-mentioned polyborosiloxane was prepared by the following steps: A silane coupling agent and tetraethyl orthosilicate were added to 1,2-dichloroethane and stirred to obtain a diluted silane solution. Benzylboronic acid was added to 1,2-dichloroethane and stirred to obtain a diluted phenylboronic acid solution. The diluted silane solution was then added dropwise to the diluted phenylboronic acid solution. After the addition was complete, the temperature was raised to 80°C, and the reaction was carried out for 8 hours. After the reaction was completed, 1,2-dichloroethane was removed by rotary evaporation to obtain the polyborosiloxane. The ratio of silane coupling agent, tetraethyl orthosilicate, and phenylboronic acid was 0.1 mol: 0.5 mol: 0.1 mol. The silane coupling agent was γ-glycidoxypropyltrimethoxysilane.

[0044] Comparative Example 1

[0045] Compared with Example 1, this comparative example differs in that polysiloxane is replaced with a binder, while the other raw materials and preparation process remain the same as in Example 1.

[0046] Comparative Example 2

[0047] The difference between this comparative example and Example 1 is that the polystyrene hollow glass microsphere composite particles are replaced with commercially available expandable polystyrene, i.e., without hollow glass microspheres as the core.

[0048] Comparative Example 3

[0049] Compared with Comparative Example 2, the difference in this comparative example is that polysiloxane is replaced with a binder, while the other raw materials and preparation process remain the same as in Example 1.

[0050] The test samples prepared in Examples 1-6 and Comparative Examples 1-3 were tested.

[0051] Compressive strength was tested according to ASTM D1621, and the thermal conductivity of the molded material was measured using a thermal conductivity meter. Freeze-thaw resistance was tested with 20 freeze-thaw cycles under the following conditions: humidity 20%. The specimens were frozen at -20°C for 12 hours, then removed, heated to 25°C, and held at that temperature for 12 hours, constituting one freeze-thaw cycle. After completing 20 freeze-thaw cycles, the compressive strength of the specimens was tested.

[0052] The flame retardant rating was evaluated according to GB 8624-2012; performance tests were conducted on Examples 1-6 and Comparative Examples 1-3, and the results are shown in Table 1: Table 1

[0053] As can be seen from Table 1, the polystyrene insulation material prepared by this invention incorporates polyborosiloxane and hollow glass microspheres, giving it a high thermal conductivity and high stability.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a polystyrene thermal insulation material, characterized in that, The process includes the following steps: pre-foaming polystyrene hollow glass microsphere composite particles and a foaming agent under a pressure of 0.1-0.3 MPa and a temperature of 70-90℃ to obtain pre-foamed particles; mixing polyisocyanate and polyol components in a mass ratio of 1.4-1.6:1 to obtain a binder; the polyol component includes polyol, catalyst, and flame retardant; mixing the pre-foamed particles, binder, and polysiloxane, and expanding and foaming them under a pressure of 0.2-1.0 MPa and a temperature of 115-130℃ to obtain polystyrene insulation material.

2. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, The mass ratio of polystyrene hollow glass microsphere composite particles, foaming agent, binder and polysiloxane is 100:6-10:10-20:5-8.

3. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, The mass ratio of polyol, catalyst and flame retardant is 100:3.3-3.5:30-35.

4. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, The polyol is at least one of polyester polyol and polyether polyol.

5. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, The catalyst is 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate and potassium acetate in a mass ratio of 1:3; the flame retardant is tris(2-chloropropyl) phosphate; and the polyisocyanate is polymethylene polyphenyl polyisocyanate.

6. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, Polystyrene hollow glass microsphere composite particles are prepared by the following steps: water, tricalcium phosphate and polyvinyl alcohol are mixed and the pH is adjusted to 7-8 to obtain an aqueous phase mixture. Styrene, benzoyl peroxide, tributyl phosphate and hydrophobically treated hollow glass microspheres are mixed to obtain an oil phase mixture. The oil phase mixture is added dropwise to the aqueous phase mixture and stirred at 85-90℃ for 3-4 hours to obtain polystyrene hollow glass microsphere composite particles.

7. The method for preparing a polystyrene thermal insulation material according to claim 6, characterized in that, The particle size of hollow glass microspheres is 80-100μm.

8. The method for preparing a polystyrene thermal insulation material according to claim 1, characterized in that, The polysiloxane is prepared by the following steps: adding silane coupling agent and tetraethyl orthosilicate to a solvent and stirring to obtain a silane dilution; adding phenylboronic acid to a solvent and stirring to obtain a phenylboronic acid dilution; adding the silane dilution dropwise to the phenylboronic acid dilution; after the addition is complete, heating to 70-80℃ and reacting for 8-9 hours to obtain polyborosiloxane; the ratio of silane coupling agent, tetraethyl orthosilicate and phenylboronic acid is 0.1 mol: 0.4-0.6 mol: 0.1 mol.

9. A method for preparing a polystyrene thermal insulation material according to claim 8, characterized in that, The silane coupling agent is one of vinylsiloxane or epoxysiloxane.

10. A polystyrene thermal insulation material, characterized in that, Prepared by the method described in any one of claims 1-9.

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