Reflective heat-insulation energy-saving acrylic plate and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a reflective heat-insulation energy-saving acrylic plate and a preparation method thereof. According to the preparation method, the POSS material and the calcium silicate are added into the main raw material methyl methacrylate to obtain the acrylic base material, then the surface of the base material is coated with the coating containing the silicon dioxide, the reflective heat-insulation energy-saving acrylic plate is prepared, through the synergistic effect of the multiple components, the tensile strength of the acrylic plate is effectively improved, the vicat softening temperature is increased, and the tensile strength of the reflective heat-insulation energy-saving acrylic plate is improved. And good heat insulation performance is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a reflective heat-insulating energy-saving acrylic board and a preparation method thereof. Background Art

[0002] Acrylic sheet, commonly known as organic glass, is mainly composed of polymethyl methacrylate (PMMA). It has many advantages that inorganic glass does not have, such as excellent optical properties, acid and alkali resistance, good electrical insulation and biocompatibility, easy molding and processing, low relative density, high mechanical strength, etc. It is widely used in construction, manufacturing, aerospace, biomedicine and daily life. In the current era of rapid economic development, people pay special attention to the use of high-performance materials. More and more materials with excellent characteristics have become the first choice for use in this era. Therefore, acrylic sheet materials with special functions have also become the focus of the industry.

[0003] A Chinese patent (publication number CN115353703B) discloses an outdoor anti-aging acrylic sheet and its preparation process. By using dibutyl phthalate and divinylbenzene as crosslinking agents and methyl methacrylate as a comonomer, the linear structure of polymethacrylate is transformed into a three-dimensional structure to improve its heat resistance; using methyl methacrylate as a monomer, trimethylolpropane triacrylate as a crosslinking agent, toluene and emulsified water as porogens, a suspension polymerization method is used to prepare porous resin microspheres, which effectively improves the lightweight of the acrylic sheet; cellulose acetate with double bonds is introduced into the anti-aging layer; a mica / cerium oxide composite material is prepared by an in-situ growth method, and then it is modified with aluminum hydroxide and disodium stearoyl glutamate to effectively enhance the anti-aging performance of the acrylic sheet. However, the acrylic sheet in the prior art has problems such as low tensile strength, low Vicat softening temperature, and the need to improve thermal insulation performance, which affects its further promotion and application.

[0004] Therefore, how to introduce suitable functional components into the acrylic substrate and realize the composite coating on the surface of the substrate to effectively improve the tensile strength of the acrylic board, increase the Vicat softening temperature, and obtain good thermal insulation performance has become a direction that needs to be focused on. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a reflective heat-insulating energy-saving acrylic sheet and a preparation method thereof, aiming to solve the problems of the existing acrylic sheets, such as low tensile strength, low Vicat softening temperature, and the need to improve thermal insulation performance.

[0006] In the present invention, an acrylic substrate is obtained by adding POSS material and calcium silicate to the main raw material methyl methacrylate, and then a coating containing silica is coated on the surface of the substrate to prepare a reflective heat-insulating and energy-saving acrylic sheet. Through the synergistic effect of multiple components, the tensile strength of the acrylic sheet is effectively improved, the Vicat softening temperature is increased, and good heat-insulating performance is obtained.

[0007] The technical solution of the present invention is as follows: In the first aspect of the present invention, a method for preparing a reflective heat-insulating and energy-saving acrylic sheet is provided, including the following steps: S1: By weight, 70-80 parts of methyl methacrylate, 6-8 parts of POSS material, 4-8 parts of calcium silicate, 2-4 parts of dibutyl phthalate, 2-4 parts of divinylbenzene, and 0.04-0.08 parts of azobisisobutyronitrile are mixed for polymerization reaction to obtain an acrylic substrate; S2: 20-30 parts of silica and 1-3 parts of hydroxyethyl cellulose are added to a mixed solution of 30-50 parts of absolute ethanol and 10-20 parts of water, ultrasonically dispersed evenly, and then 4-6 parts of γ-glycidoxypropyltrimethoxysilane are added for stirring reaction to obtain a coating agent; S3: The coating agent is coated on the surface of the acrylic substrate, and then coating composite treatment is carried out to obtain a reflective heat-insulating and energy-saving acrylic sheet.

[0008] As a preferred scheme, the weight parts of the methyl methacrylate in the present invention can be 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, 80 parts, etc.

[0009] As a preferred scheme, the weight parts of the POSS material in the present invention can be 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, etc.

[0010] As a preferred scheme, the weight parts of the calcium silicate in the present invention can be 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc.

[0011] As a preferred scheme, the weight parts of the dibutyl phthalate in the present invention can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0012] As a preferred scheme, the weight parts of the divinylbenzene in the present invention can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0013] As a preferred scheme, the weight parts of the azobisisobutyronitrile in the present invention can be 0.04 parts, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, etc.

[0014] As a preferred embodiment, the weight parts of the silica in the present invention may be 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, etc.

[0015] As a preferred embodiment, the weight parts of the hydroxyethyl cellulose in the present invention may be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0016] As a preferred embodiment, the weight parts of the γ-glycidoxypropyltrimethoxysilane in the present invention may be 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, etc.

[0017] As a preferred embodiment, the conditions of the polymerization reaction in S1 include: heating to 70-80 °C under stirring for 40-50 min, then cooling to room temperature, and then heating to 90-95 °C for heat preservation for 120-140 min, and then cooling.

[0018] As a preferred embodiment, the conditions of the stirring reaction in S2 include: first adjusting the pH to 2.0-2.4 with hydrochloric acid, then performing a first stirring for 1-2 h at 40-50 °C, and then heating to 70-80 °C for a second stirring for 2-3 h.

[0019] As a preferred embodiment, the conditions of the coating composite treatment in S3 include: naturally air-drying and leveling for 30-40 min at room temperature, transferring to an oven and drying at 40-50 °C for 30-40 min, and then heating to 80-86 °C for continuous drying for 1-3 h.

[0020] As a preferred embodiment, the preparation of the POSS material: mixing 80-90 parts of absolute ethanol and 10-20 parts of deionized water evenly, adjusting the pH to 2.4-2.8, and dropwise adding 16-20 parts of KH570 for hydrolysis and polycondensation to obtain the POSS material.

[0021] As a preferred embodiment, the conditions of the hydrolysis and polycondensation include: controlling the temperature at 38-40 °C for constant temperature reaction for 40-48 h, then adjusting the pH to 6.8-7.2 with a 10% sodium hydroxide solution by mass concentration, decompressing and pumping to remove absolute ethanol, dissolving with chloroform, washing to remove impurities, and drying.

[0022] The POSS material itself belongs to a rigid structure. Introducing it into the acrylic plate can improve the flexible characteristics of the acrylic plate itself and limit the movement of polymer chain segments at high temperatures; at the same time, the hybrid material formed by introducing the POSS material is highly cross-linked in structure, making the intermolecular binding tight, increasing the intermolecular force, and thus effectively improving the Vicat softening temperature.

[0023] As a preferred embodiment, the calcium silicate is amino-functionalized calcium silicate; The preparation method of the amino calcium silicate comprises: dissolving 14 to 18 parts of sodium silicate nonahydrate in 40 to 50 parts of deionized water to form a sodium silicate solution, adding 14 to 18 parts of calcium nitrate tetrahydrate to 80 to 100 parts of deionized water and stirring to dissolve, first adding 0.6 to 0.8 parts of sodium dodecyl sulfonate for stirring treatment, then dropping 40 to 50 parts of the sodium silicate solution for synthesis reaction to obtain mesoporous calcium silicate; adding 4 to 8 parts of mesoporous calcium silicate to 80 to 100 parts of toluene and stirring sufficiently, then adding 2 to 4 parts of 3-aminopropyltriethoxysilane for coupling treatment to obtain the amino calcium silicate.

[0024] As a preferred solution, the conditions of the synthesis reaction include: controlling the temperature to 40-50°C for constant temperature reaction for 4-6 hours, cooling to room temperature for aging for 20-24 hours, washing with water, extracting with anhydrous ethanol, and vacuum drying.

[0025] As a preferred solution, the stirring treatment conditions include: stirring at a speed of 100-120 r / min for 60-80 min at 40-50° C.

[0026] As a preferred solution, the coupling treatment conditions include: heating the reaction at 110-120° C. for 20-24 hours, filtering, washing, drying, and grinding.

[0027] As a rigid nanofiller, amino calcium silicate can be evenly dispersed in the polymer matrix of the acrylic board. When the material is stretched by external force, amino calcium silicate shares the load through physical entanglement and stress transfer, delaying crack propagation. At the same time, amino calcium silicate can also limit the movement of polymer chain segments, inhibit the deformation and slippage of the material when subjected to force, thereby improving the tensile strength.

[0028] As a preferred solution, the silicon dioxide is a silicon dioxide aerogel composite material; The preparation method of the silica aerogel composite material comprises: adding 10 to 14 parts of tetraethyl silicate to a mixture of 80 to 90 parts of anhydrous ethanol and 30 to 40 parts of deionized water by weight, stirring evenly, then hydrolyzing to obtain a sol, and then adding 1 to 3 parts of boehmite for gelation treatment to obtain the silica aerogel composite material.

[0029] As a preferred solution, the gelation treatment conditions include: uniform ultrasonic dispersion, then adjusting the pH to 5.8-6.2 for gelation, aging at 46-50° C. for 48-50 h after gelation, then immersing in a n-hexane / trimethylchlorosilane mixture (the mass ratio of n-hexane to trimethylchlorosilane is 9:1), modifying at 24-28° C. for 20-24 h, washing with n-hexane, and drying to obtain a silica aerogel composite material.

[0030] As a preferred solution, the conditions for hydrolysis include: first stirring at a speed of 90 - 100 r / min for 10 - 20 min, then adjusting the pH to 2.2 - 2.6 with 1 mol / L hydrochloric acid solution, and stirring for hydrolysis for 30 - 40 min.

[0031] The coating formed by the silica aerogel composite material can improve the heat insulation performance from both the gas phase and the solid phase. On the one hand, the pore structure of the aerogel can effectively block the movement of gas molecules and reduce convective heat transfer. On the other hand, the amorphous / nanocrystalline structure of boehmite and silica increases phonon scattering and reduces lattice heat conduction, further reducing the heat conduction efficiency.

[0032] In the second aspect of the present invention, a reflective heat-insulating and energy-saving acrylic board is provided, which is prepared by the method described in the first aspect.

[0033] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, a coating material is formed on the surface of the acrylic substrate. The coupling agent γ-glycidoxypropyltrimethoxysilane in the coating can act as a bridge to bridge the POSS material and the silica aerogel composite material. At the same time, the introduced epoxy group can combine with the amino group of the amino-functionalized calcium silicate, enabling the coating to effectively adhere to the surface of the acrylic board and improving the tensile strength and Vicat softening temperature of the acrylic board by forming a high-density spatial interconnected structure.

[0034] (2) The inorganic siloxane cage structure of the POSS material in the substrate of the present invention has a low thermal conductivity, and the interface formed with the organic matrix of the acrylic board can form a microscopic barrier layer to hinder heat transfer; the mesoporous structure of the amino-functionalized calcium silicate can form tiny air pockets or pore structures inside the acrylic board, effectively reducing the thermal conductivity of the overall material; the silica aerogel composite material in the coating can improve the heat insulation performance from both the gas phase and the solid phase; the acrylic board of the present invention first realizes heat isolation in the gas phase and the solid phase through the silica aerogel in the surface coating. When heat enters the matrix, the microscopic barrier layer formed by the POSS material can hinder heat transfer, while the mesoporous structure of the amino-functionalized calcium silicate can further reduce the thermal conductivity. Through the synergistic effect of multiple components, the heat insulation performance of the acrylic board is improved.

[0035] (3) The POSS material of the present invention itself belongs to a rigid structure. Introducing it into the acrylic board can improve the flexible characteristics of the acrylic board itself and limit the movement of polymer chain segments at high temperatures; at the same time, the hybrid material formed by the introduction of the POSS material is highly cross-linked in structure, making the intermolecular binding tight and increasing the intermolecular force, thereby effectively improving the Vicat softening temperature.

[0036] (4)The calcium silicate aminated by the present invention can be uniformly dispersed in the polymer matrix of the acrylic plate as a rigid nano-filler. When the material is stretched by an external force, the calcium silicate aminated bears the load through physical entanglement and stress transfer, delaying crack propagation. At the same time, the calcium silicate aminated can also restrict the movement of polymer segments, inhibit the deformation and slip of the material when stressed, thereby improving the tensile strength.

[0037] (5)The coating formed by the silica aerogel composite material of the present invention can improve the heat insulation performance from both the gas phase and the solid phase. On the one hand, the pore structure of the aerogel can effectively block the movement of gas molecules, reducing convective heat transfer. On the other hand, the amorphous / nanocrystalline structure of boehmite and silica increases phonon scattering and reduces lattice heat conduction, further reducing the heat conduction efficiency. Specific Embodiments

[0038] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the said examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0039] The sources of some components in the examples and comparative examples are as follows: Methyl methacrylate, CAS No. 80-62-6, purchased from Shanghai Macklin Biochemical Co., Ltd.; Commercially available calcium silicate, CAS No. 1344-95-2, purchased from Sinopharm Chemical Reagent Co., Ltd.; Dibutyl phthalate, CAS No. 84-74-2, purchased from Shanghai Macklin Biochemical Co., Ltd.; Divinylbenzene, CAS No. 1321-74-0, purchased from Sinopharm Chemical Reagent Co., Ltd.; 2,2'-Azobis(2-methylpropionitrile), CAS No. 78-67-1, purchased from Sinopharm Chemical Reagent Co., Ltd.; Commercially available silica, product number S118568, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; γ-Glycidoxypropyltrimethoxysilane, CAS No. 2530-83-8, purchased from Shanghai Macklin Biochemical Co., Ltd.; Hydroxyethyl cellulose, CAS No. 9004-62-0, purchased from Shanghai Macklin Biochemical Co., Ltd.; KH570, product number S111153, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Absolute ethanol, CAS No. 64-17-5, purchased from Sinopharm Chemical Reagent Co., Ltd.; Sodium hydroxide, CAS No. 1310-73-2, purchased from Sinopharm Chemical Reagent Co., Ltd.; Sodium silicate nonahydrate, CAS No. 13517-24-3, purchased from Sinopharm Chemical Reagent Co., Ltd.; Calcium nitrate tetrahydrate, CAS No. 13477-34-4, purchased from Sinopharm Chemical Reagent Co., Ltd.; Sodium dodecyl sulfonate, CAS No. 2386-53-0, purchased from Shanghai Macklin Biochemical Co., Ltd.; Toluene, CAS No. 108-88-3, purchased from Sinopharm Chemical Reagent Co., Ltd.; 3-Aminopropyltriethoxysilane, CAS No. 919-30-2, purchased from Shanghai Macklin Biochemical Co., Ltd.; Tetraethyl orthosilicate, CAS No. 78-10-4, purchased from Shanghai Macklin Biochemical Co., Ltd.; Boehmite, product number B302379, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; n-Hexane, CAS No. 110-54-3, purchased from Sinopharm Chemical Reagent Co., Ltd.; Trimethylchlorosilane, CAS No. 75-77-4, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0040] Example 1 This example provides a method for preparing a reflective heat-insulating and energy-saving acrylic board, including the following steps: S1: By weight, 80 parts of methyl methacrylate, 8 parts of POSS material, 8 parts of aminated calcium silicate, 4 parts of dibutyl phthalate, 4 parts of divinylbenzene and 0.08 part of azobisisobutyronitrile are mixed for polymerization reaction. The temperature is raised to 80 °C under stirring and reacted for 40 min, then cooled to room temperature, and then raised to 95 °C for heat preservation for 120 min, and then cooled to obtain an acrylic substrate; S2: 30 parts of silica aerogel composite material and 3 parts of hydroxyethyl cellulose are added to a mixed solution of 50 parts of absolute ethanol and 10 parts of water, and ultrasonically dispersed evenly, and then 6 parts of γ-glycidoxypropyltrimethoxysilane are added for stirring reaction. First, the pH is adjusted to 2.4 with hydrochloric acid, and then stirred at 50 °C for 1 h for the first time, and then raised to 80 °C for stirring for 2 h for the second time to obtain a coating agent; S3: The coating agent is coated on the surface of the acrylic substrate, and then subjected to coating composite treatment, naturally air-dried and leveled at room temperature for 40 min, transferred to an oven and dried at 50 °C for 30 min, and then raised to 86 °C and dried for 1 h to obtain a reflective heat-insulating and energy-saving acrylic board.

[0041] Preparation of the POSS material: Mix 90 parts of absolute ethanol and 10 parts of deionized water evenly, adjust the pH to 2.8, dropwise add 20 parts of KH570 for hydrolysis and polycondensation, control the temperature at 40 °C for isothermal reaction for 40 h, then adjust the pH to 7.2 with a sodium hydroxide solution with a mass concentration of 10%, remove absolute ethanol by reduced pressure pumping, dissolve with chloroform, wash with water to remove impurities, and dry to obtain the POSS material.

[0042] Preparation of the aminated calcium silicate: By weight, dissolve 18 parts of sodium silicate nonahydrate in 50 parts of deionized water to form a sodium silicate solution, add 18 parts of calcium nitrate tetrahydrate to 100 parts of deionized water and stir to dissolve. First, add 0.8 part of sodium dodecyl sulfonate for stirring treatment (stir at a speed of 120 r / min for 60 min at 50 °C), then dropwise add 50 parts of the sodium silicate solution for synthesis reaction, control the temperature at 50 °C for isothermal reaction for 4 h, cool to room temperature and age for 24 h, wash with water, extract with absolute ethanol, and dry in vacuum to obtain mesoporous calcium silicate; Add 8 parts of mesoporous calcium silicate to 100 parts of toluene and stir well, then add 4 parts of 3-aminopropyltriethoxysilane for coupling treatment, heat and react at 120 °C for 20 h, filter, wash with water, dry, and grind to obtain aminated calcium silicate.

[0043] Preparation of the silica aerogel composite material: By weight, add 14 parts of tetraethyl orthosilicate to a mixture of 90 parts of absolute ethanol and 40 parts of deionized water and stir evenly, then carry out hydrolysis (first stir at a speed of 100 r / min for 10 min, then adjust the pH to 2.6 with a 1 mol / L hydrochloric acid solution and stir and hydrolyze for 40 min) to obtain a sol, then add 3 parts of boehmite and disperse evenly by ultrasonic wave, then adjust the pH to 6.2 for gelation. After gelation is completed, age at 50 °C for 48 h, then immerse in a n-hexane / trimethylchlorosilane mixture (the mass ratio of n-hexane to trimethylchlorosilane is 9:1), modify at 28 °C for 20 h, wash with n-hexane, and dry to obtain the silica aerogel composite material.

[0044] Example 2 This example provides a preparation method of a reflective heat-insulating and energy-saving acrylic board, including the following steps: S1: By weight, mix 70 parts of methyl methacrylate, 6 parts of the POSS material, 4 parts of the aminated calcium silicate, 2 parts of dibutyl phthalate, 2 parts of divinylbenzene, and 0.04 part of azobisisobutyronitrile for polymerization reaction. Heat up to 70 °C under stirring and react for 50 min, then cool to room temperature, and then heat up to 90 °C for heat preservation for 140 min, and cool to obtain an acrylic substrate. S2: 20 parts of silica aerogel composite material and 1 part of hydroxyethyl cellulose are added to a mixture of 30 parts of anhydrous ethanol and 10 parts of water for uniform ultrasonic dispersion, and then 4 parts of γ-glycidyloxypropyltrimethoxysilane are added for stirring reaction, and the pH is first adjusted to 2.0 with hydrochloric acid, and then stirred at 40°C for 2 hours, and then heated to 70°C for a second stirring for 3 hours to obtain a coating agent; S3: Apply the coating agent on the surface of the acrylic substrate, and then perform coating composite treatment, naturally air dry and level for 30 minutes at room temperature, transfer to an oven and dry at 40°C for 40 minutes, then heat up to 80°C and continue drying for 3 hours to obtain a reflective heat-insulating energy-saving acrylic board.

[0045] Preparation of the POSS material: 80 parts of anhydrous ethanol and 20 parts of deionized water are mixed uniformly, the pH is adjusted to 2.4, 16 parts of KH570 are added dropwise for hydrolysis and polycondensation, the temperature is controlled to be 38°C and the reaction is carried out at a constant temperature for 48 hours, and then the pH is adjusted to 6.8 with a sodium hydroxide solution with a mass concentration of 10%, the anhydrous ethanol is removed by vacuum pumping, chloroform is dissolved, water is washed to remove impurities, and the POSS material is dried.

[0046] The preparation of the amino calcium silicate is as follows: in parts by weight, 14 parts of sodium silicate nonahydrate are dissolved in 40 parts of deionized water to form a sodium silicate solution, 14 parts of calcium nitrate tetrahydrate are added to 80 parts of deionized water and stirred to dissolve, 0.6 parts of sodium dodecyl sulfate are first added for stirring treatment (stirring at 100 r / min for 80 minutes at 40° C.), and then 40 parts of the sodium silicate solution are added dropwise for synthesis reaction, the temperature is controlled to be 40° C. for constant temperature reaction for 6 hours, the temperature is lowered to room temperature for aging for 20 hours, washed with water, extracted with anhydrous ethanol, and vacuum dried to obtain mesoporous calcium silicate; 4 parts of mesoporous calcium silicate are added to 80 parts of toluene and stirred sufficiently, and then 2 parts of 3-aminopropyltriethoxysilane are added for coupling treatment, heated for reaction at 110° C. for 24 hours, filtered, washed with water, dried, and ground to obtain the amino calcium silicate.

[0047] Preparation of the silica aerogel composite material: by weight, 10 parts of tetraethyl silicate are added to a mixture of 90 parts of anhydrous ethanol and 30 parts of deionized water, stirred evenly, and then hydrolyzed (first stirred at a speed of 90 r / min for 20 minutes, then adjusted to pH 2.2 with a 1 mol / L hydrochloric acid solution, and stirred for hydrolysis for 30 minutes) to obtain a sol, and then 1 part of boehmite is added for ultrasonic dispersion, and then the pH is adjusted to 5.8 for gelation. After the gelation is completed, it is aged at 46° C. for 50 hours, and then immersed in a mixture of n-hexane / trimethylchlorosilane (the mass ratio of n-hexane to trimethylchlorosilane is 9:1), modified at 24° C. for 24 hours, washed with n-hexane, and dried to obtain a silica aerogel composite material.

[0048] Example 3 This embodiment provides a method for preparing a reflective heat-insulating energy-saving acrylic board, comprising the following steps: S1: In parts by weight, 75 parts of methyl methacrylate, 7 parts of POSS material, 6 parts of calcium silicate amino, 3 parts of dibutyl phthalate, 3 parts of divinylbenzene and 0.06 parts of azobisisobutyronitrile were mixed for polymerization reaction, heated to 75°C for reaction for 45 minutes under stirring, then cooled to room temperature, heated to 92°C for a second time for 130 minutes, and cooled to obtain an acrylic substrate; S2: 25 parts of silica aerogel composite material and 2 parts of hydroxyethyl cellulose are added to a mixture of 40 parts of anhydrous ethanol and 15 parts of water for uniform ultrasonic dispersion, and then 5 parts of γ-glycidyloxypropyltrimethoxysilane are added for stirring reaction, and the pH is first adjusted to 2.2 with hydrochloric acid, and then stirred at 45°C for 1.5 hours, and then heated to 75°C for a second stirring for 2.5 hours to obtain a coating agent; S3: Apply the coating agent on the surface of the acrylic substrate, and then perform coating composite treatment, naturally air dry and level for 35 minutes at room temperature, transfer to an oven and dry at 46°C for 34 minutes, then heat up to 83°C and continue drying for 2 hours to obtain a reflective, heat-insulating and energy-saving acrylic board.

[0049] Preparation of the POSS material: 85 parts of anhydrous ethanol and 15 parts of deionized water are mixed uniformly, the pH is adjusted to 2.6, 18 parts of KH570 are added dropwise for hydrolysis and polycondensation, the temperature is controlled to be 39° C. and the reaction is carried out at a constant temperature for 44 hours, and then the pH is adjusted to 6.9 with a sodium hydroxide solution with a mass concentration of 10%, the anhydrous ethanol is removed by vacuum pumping, chloroform is dissolved, water is washed to remove impurities, and the POSS material is dried.

[0050] The preparation of the amino calcium silicate is as follows: by weight, 16 parts of sodium silicate nonahydrate are dissolved in 45 parts of deionized water to form a sodium silicate solution, 16 parts of calcium nitrate tetrahydrate are added to 90 parts of deionized water and stirred to dissolve, 0.7 parts of sodium dodecyl sulfate are first added for stirring treatment (stirring at a speed of 110r / min for 70min at 45°C), and then 45 parts of the sodium silicate solution are added dropwise for synthesis reaction, the temperature is controlled to be 44°C for constant temperature reaction for 5h, the temperature is lowered to room temperature for aging for 22h, washed with water, extracted with anhydrous ethanol, and vacuum dried to obtain mesoporous calcium silicate; 6 parts of mesoporous calcium silicate are added to 90 parts of toluene and stirred sufficiently, and then 3 parts of 3-aminopropyltriethoxysilane are added for coupling treatment, heated for reaction at 115°C for 22h, filtered, washed with water, dried, and ground to obtain the amino calcium silicate.

[0051] Preparation of the silica aerogel composite material: By weight, 12 parts of tetraethyl orthosilicate are added to a mixed solution of 85 parts of absolute ethanol and 35 parts of deionized water and stirred evenly, and then hydrolysis is carried out (first stirred at a speed of 95 r / min for 16 min, then the pH is adjusted to 2.4 with 1 mol / L hydrochloric acid solution, and stirred and hydrolyzed for 34 min) to obtain a sol. Then, 2 parts of boehmite are added and ultrasonically dispersed evenly, and then the pH is adjusted to 6.1 for gelation. After the gelation is completed, it is aged at 48 °C for 49 h, and then immersed in a mixed solution of n-hexane / trimethylchlorosilane (the mass ratio of n-hexane to trimethylchlorosilane is 9:1), and modified at 26 °C for 22 h, washed with n-hexane, and dried to obtain the silica aerogel composite material, and the silica aerogel composite material is obtained.

[0052] Example 4 The difference between this example and Example 1 is that commercially available calcium silicate (CAS No. 1344-95-2) is used to replace the aminated calcium silicate.

[0053] Example 5 The difference between this example and Example 1 is that commercially available silica (product number S118568) is used to replace the silica aerogel composite material.

[0054] Comparative Example 1 The difference between this comparative example and Example 1 is that 8 parts of POSS material are not added to the substrate.

[0055] Comparative Example 2 The difference between this comparative example and Example 1 is that 8 parts of aminated calcium silicate are not added to the substrate.

[0056] Comparative Example 3 The difference between this comparative example and Example 1 is that 30 parts of silica aerogel composite material are not added to the coating.

[0057] The performance of the acrylic plates provided in the above examples and comparative examples was tested, and the test method is as follows: The tensile strength and Vicat softening temperature were tested according to the requirements of "GB / T 7134-2008 Cast Industrial Polymethyl Methacrylate Sheets"; the heat insulation performance was tested according to the requirements of "GB / T 42919.1-2023 Plastics - Determination of Thermal Conductivity and Thermal Diffusivity - Part 1: General Principles".

[0058] The above performance test data are shown in Table 1.

[0059] Table 1 Performance Test Results

[0060] As can be seen from the above, the present invention prepares a reflective heat-insulating and energy-saving acrylic board (Examples 1 to 3) by adding POSS material and amino-functionalized calcium silicate to an acrylic substrate and simultaneously coating a coating containing a silica aerogel composite material on the surface of the substrate. Its comprehensive performance is the best, with a tensile strength of 136 to 139 MPa, a Vicat softening temperature of 119 to 122 °C, and a thermal conductivity of 0.018 to 0.021 W / (m·K).

[0061] Compared with Example 1, when using commercially available calcium silicate (CAS No. 1344-95-2) to replace amino-functionalized calcium silicate, the tensile strength decreases, the Vicat softening temperature becomes smaller, and the thermal conductivity increases (Example 4); compared with Example 1, when using commercially available silica (product number S118568) to replace the silica aerogel composite material, the tensile strength decreases, the Vicat softening temperature becomes smaller, and the thermal conductivity increases (Example 5); compared with Example 1, when 8 parts of POSS material are not added to the substrate, the tensile strength decreases, the Vicat softening temperature becomes smaller, and the thermal conductivity increases (Comparative Example 1); compared with Example 1, when 8 parts of amino-functionalized calcium silicate are not added to the substrate, the tensile strength decreases, the Vicat softening temperature becomes smaller, and the thermal conductivity increases (Comparative Example 2); compared with Example 1, when 30 parts of the silica aerogel composite material are not added to the coating, the tensile strength decreases, the Vicat softening temperature becomes smaller, and the thermal conductivity increases (Comparative Example 3).

[0062] In summary, the present invention prepares a reflective heat-insulating and energy-saving acrylic board by adding POSS material and calcium silicate to the main raw material methyl methacrylate to obtain an acrylic substrate, and then coating a coating containing silica on the surface of the substrate. Through the synergistic effect of multiple components, the tensile strength of the acrylic board is effectively improved, the Vicat softening temperature is increased, and good heat-insulating performance is obtained.

Claims

1. A preparation method of a reflective heat-insulating and energy-saving acrylic board, characterized in that it includes the following steps: S1: By weight, mix 70-80 parts of methyl methacrylate, 6-8 parts of POSS material, 4-8 parts of calcium silicate, 2-4 parts of dibutyl phthalate, 2-4 parts of divinylbenzene and 0.04-0.08 parts of azobisisobutyronitrile for polymerization reaction to obtain an acrylic substrate; S2: Add 20-30 parts of silicon dioxide and 1-3 parts of hydroxyethyl cellulose to a mixed solution of 30-50 parts of absolute ethanol and 10-20 parts of water, ultrasonically disperse evenly, and then add 4-6 parts of γ-glycidoxypropyltrimethoxysilane for stirring reaction to obtain a coating agent; S3: Coating the coating agent on the surface of the acrylic substrate, and then performing coating composite treatment to obtain a reflective heat-insulating and energy-saving acrylic board; Preparation of the POSS material: Mix 80-90 parts of absolute ethanol and 10-20 parts of deionized water evenly, adjust the pH to 2.4-2.8, and dropwise add 16-20 parts of KH570 for hydrolysis and polycondensation to obtain the POSS material.

2. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that the conditions of the polymerization reaction in S1 include: heating to 70-80 °C under stirring for 40-50 min, then cooling to room temperature, and then heating to 90-95 °C for the second time and keeping warm for 120-140 min, and then cooling.

3. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that the conditions of the stirring reaction in S2 include: first adjusting the pH to 2.0-2.4 with hydrochloric acid, then performing the first stirring for 1-2 h at 40-50 °C, and then heating to 70-80 °C for the second stirring for 2-3 h.

4. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that the conditions of the coating composite treatment in S3 include: naturally air-drying and leveling at room temperature for 30-40 min, transferring to an oven and drying at 40-50 °C for 30-40 min, and then heating to 80-86 °C and continuing to dry for 1-3 h.

5. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that the conditions of the hydrolysis and polycondensation include: controlling the temperature at 38-40 °C for constant temperature reaction for 40-48 h, then adjusting the pH to 6.8-7.2 with a 10% mass concentration sodium hydroxide solution, decompressing and pumping to remove absolute ethanol, dissolving with chloroform, washing to remove impurities, and drying.

6. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that the calcium silicate is amino-functionalized calcium silicate; The preparation method of the amino-functionalized calcium silicate comprises: by weight, dissolving 14-18 parts of sodium silicate nonahydrate in 40-50 parts of deionized water to form a sodium silicate solution, adding 14-18 parts of calcium nitrate tetrahydrate to 80-100 parts of deionized water and stirring to dissolve, first adding 0.6-0.8 part of sodium dodecyl sulfonate for stirring treatment, and then dropping 40-50 parts of the sodium silicate solution for a synthesis reaction to obtain mesoporous calcium silicate; adding 4-8 parts of the mesoporous calcium silicate into 80-100 parts of toluene and stirring well, and then adding 2-4 parts of 3-aminopropyltriethoxysilane for coupling treatment to obtain the amino-functionalized calcium silicate.

7. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 6, characterized in that The conditions of the synthesis reaction include: controlling the temperature at 40-50 °C for a constant-temperature reaction for 4-6 h, cooling to room temperature for aging for 20-24 h, washing with water, extracting with absolute ethanol, and drying under vacuum.

8. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 1, characterized in that The silicon dioxide is a silicon dioxide aerogel composite material; The preparation method of the silicon dioxide aerogel composite material comprises: by weight, adding 10-14 parts of tetraethyl orthosilicate into a mixed solution of 80-90 parts of absolute ethanol and 30-40 parts of deionized water and stirring evenly, then carrying out hydrolysis to obtain a sol, and adding 1-3 parts of boehmite for gelling treatment to obtain the silicon dioxide aerogel composite material.

9. The preparation method of a reflective heat-insulating and energy-saving acrylic board according to claim 8, characterized in that The conditions of the gelling treatment include: ultrasonic dispersion to be uniform, then adjusting the pH to 5.8-6.2 for gelation, after the gelation is completed, aging at 46-50 °C for 48-50 h, then immersing in a n-hexane / trimethylchlorosilane mixed solution, modifying at 24-28 °C for 20-24 h, washing with n-hexane, and drying to obtain the silicon dioxide aerogel composite material.

10. A reflective heat-insulating and energy-saving acrylic board, characterized in that, Prepared by the method according to any one of claims 1-9.

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