High-strength and high-hardness acrylic composite board

Abstract

The invention relates to the technical field of materials, and discloses a high-strength and high-hardness acrylic composite board which is prepared from methyl methacrylate, an initiator, a rectorite modified material and other raw materials through prepolymerization, mixing and curing. Wherein the rectorite modified material is prepared by forming a macromolecular polymeric substance which is connected by ether bonds and is alternately connected with polyethylene glycol and adamantane on the surface of rectorite, and the macromolecular polymeric substance can participate in the subsequent heating and curing process to realize crosslinking of polymethyl methacrylate; compared with the prior art, the preparation method has the advantages that the prepared acrylic plate is higher in structural density and further shows higher hardness, in addition, a macromolecular polymeric substance structure contains an adamantane rigid ring, so that the stability of an acrylic molecular chain can be improved, and the rectorite can also efficiently exert a self-reinforcing effect, so that the reinforcement of the plate is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and particularly relates to a high-strength and high-hardness acrylic composite board. Background Art

[0002] Acrylic (PMMA) is a classic polymer material, which has characteristics such as high transparency, excellent processing performance and weather resistance, and occupies an important position in the fields of architectural decoration, advertising display, medical devices, etc. However, the molecular structure of acrylic determines the limitations of its physical properties. Firstly, the weak interaction between the ester group and the methyl group in the acrylic molecular chain causes the material to be easily deformed when stressed, and its surface pencil hardness usually can only reach HB - 2H. In addition, the strength performance of the acrylic board is also poor. Therefore, the inherent brittleness, low hardness and insufficient impact resistance of acrylic directly lead to the shortening of product life and the increase of maintenance cost, restricting its competitiveness in high-end application scenarios.

[0003] Currently, the enhancement and modification of acrylic are generally carried out by adding inorganic additives. By utilizing the advantages of inorganic additives and combining them with the advantages of acrylic to form complementary advantages, the comprehensive performance of acrylic can be enhanced to a certain extent. However, there are interface problems between the inorganic additives themselves and acrylic, resulting in the easy agglomeration of inorganic additives. It is not only difficult to achieve good enhancement and modification, but also may have a negative impact on the mechanical strength of acrylic due to a large addition amount.

[0004] Based on this, the present invention provides an acrylic composite board, which can solve the problems existing in the prior art. Summary of the Invention

[0005] In order to solve the problems mentioned in the background art, the purpose of the present invention is to provide a high-strength and high-hardness acrylic composite board.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A high-strength and high-hardness acrylic composite board, comprising the following raw materials in parts by weight: 65 - 80 parts of methyl methacrylate, 0.2 - 0.5 part of initiator, 2 - 4.5 parts of rectorite modified material, 0.5 - 1 part of defoaming agent.

[0007] As a further scheme of the present invention, the preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator into a polymerization kettle. After adding, start stirring. When a uniform solution is formed, start heating and maintain the temperature at 80 - 82°C for 30 - 60 minutes of heat preservation and pre-polymerization. Then stop heating and wait for it to cool naturally to form a prepolymer; Step 2: Add the rectorite modifier and defoamer to the prepolymer. After stirring and dispersing evenly, let it stand for 10 - 20 min, then pour it into a mold, keep it warm at 50 - 60 °C for 1 - 3 h, then keep it warm at 70 - 80 °C for 1 - 2 h, and finally keep it warm at 90 - 100 °C for 20 - 40 min. Demold to obtain the acrylic composite board.

[0008] As a further scheme of the present invention, the preparation method of the rectorite modifier includes the following steps: Step S1: Add the silane coupling agent to deionized water, stir evenly, hydrolyze at 50 - 60 °C for 2 - 4 h to form a hydrolysis solution; add rectorite to absolute ethanol, disperse evenly, then add the hydrolysis solution to the formed dispersion. After adding, raise the temperature to 60 - 70 °C, continuously stir for 3 - 6 h, then cool and discharge, centrifuge out the solid material, and after washing and vacuum drying treatment, obtain the rectorite with halogen substituents; Step S2: Add the rectorite with halogen substituents to N,N - dimethylformamide, ultrasonically disperse evenly, then add methacrylic acid (3,5 - dihydroxyadamantan - 1 - yl) ester and a catalyst. After adding, stir well, then control the temperature at 70 - 80 °C, keep it warm for 2 - 4 h, continue to add halogen - terminated polyethylene glycol, and further raise the temperature to 90 - 100 °C, continuously keep it warm for polymerization for 12 - 18 h, then cool and discharge to obtain the rectorite modifier.

[0009] As a further scheme of the present invention, in Step S1, the silane coupling agent is any one of 3 - chloropropyltrimethoxysilane, 3 - chloropropyltriethoxysilane, or 3 - bromopropyltriethoxysilane.

[0010] As a further scheme of the present invention, in Step S2, the preparation method of the halogen - terminated polyethylene glycol is as follows: Add polyethylene glycol to tetrahydrofuran, start stirring, and after forming a uniform solution, place it in an ice - bath environment. Then add a halogen - modified reagent and a promoter to the solution. After adding, remove it from the ice - bath, keep it warm at a temperature of 60 - 65 °C for 4 - 8 h, then evaporate to remove the solvent, collect the product to obtain the halogen - terminated polyethylene glycol.

[0011] As a further scheme of the present invention, the halogen - modified reagent is any one of chloroethyl isocyanate, 3 - chloropropyl isocyanate, or 2 - bromoethyl isocyanate.

[0012] As a further scheme of the present invention, the molecular weight of the polyethylene glycol is 200 - 600.

[0013] As a further scheme of the present invention, the promoter is any one of dibutyltin dilaurate, stannous octoate, or dibutyltin diacetate.

[0014] As a further aspect of the present invention, in step S2, the catalyst is an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution.

[0015] Specifically, first, rectorite is surface-modified with a silane coupling agent carrying a halogen substituent to obtain rectorite containing a halogen substituent. Then, using (3,5-dihydroxyadamantan-1-yl) methacrylate as a linker, first, it undergoes substitution with the rectorite containing a halogen substituent under the action of a catalyst. Then, the remaining unreacted (3,5-dihydroxyadamantan-1-yl) methacrylate in the system undergoes a continuous substitution reaction with the halogen substituents in the halogen-terminated polyethylene glycol structure of the chain extender, thereby forming a macromolecular polymeric substance with alternating polyethylene glycol and adamantane connected by ether bonds on the surface of the rectorite, and obtaining the rectorite modified material.

[0016] Among them, the halogen-terminated polyethylene glycol is prepared by using polyethylene glycol and a halogenated modification reagent as raw materials, and the hydroxyl groups and acyl halide groups in their structures undergo a condensation reaction under the action of a promoter.

[0017] As a further aspect of the present invention, the initiator is benzoyl peroxide or diisopropylbenzene peroxide; the defoamer is dimethyl silicone oil.

[0018] Advantages of the present invention: In the present invention, a macromolecular polymeric substance with alternating polyethylene glycol and adamantane connected by ether bonds is formed on the surface of rectorite to obtain the rectorite modified material. As an additive, during the subsequent heating and curing process, under the action of the initiator, a large number of unsaturated alkenyl functional groups contained in the structure of the macromolecular polymeric substance can undergo free radical polymerization with methyl methacrylate. Therefore, on the one hand, the rectorite modified material can be used as a crosslinking agent to achieve the crosslinking of polymethyl methacrylate, making the structure of the obtained acrylic sheet more dense, and thus showing higher hardness. Moreover, the macromolecular polymeric substance structure contains an adamantane rigid ring, which can improve the stability of the acrylic molecular chain and achieve the strengthening of the sheet. On the other hand, in this way, an interaction can be generated between rectorite and polymethyl methacrylate, so the compatibility between them can be effectively improved, and then the rectorite can efficiently exert its own strengthening effect, further enhancing the mechanical strength of the sheet.

[0019] Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all the above-mentioned advantages. Specific embodiments

[0020] Next, in combination with the embodiments, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Example 1

[0021] A high-strength and high-hardness acrylic composite board comprises raw materials in the following parts by weight: 65 parts of methyl methacrylate, 0.2 part of initiator benzoyl peroxide, 2 parts of rectorite modifier, 0.5 part of defoaming agent dimethyl silicone oil; The preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator benzoyl peroxide into a polymerization kettle. After adding, start stirring. When a uniform solution is formed, start heating and maintain the temperature at 80 °C for 60 minutes of heat preservation pre-polymerization. Stop heating and wait for it to cool naturally to form a prepolymer. Step 2: Add the rectorite modifier and defoaming agent dimethyl silicone oil into the prepolymer. After stirring and dispersing evenly, let it stand for 10 minutes, then pour it into a mold, carry out heat preservation treatment at 50 °C for 3 hours, then carry out heat preservation treatment at 70 °C for 2 hours, and finally carry out heat preservation treatment at 90 °C for 40 minutes, and demold to obtain the acrylic composite board.

[0022] The preparation method of the rectorite modifier comprises the following steps: Step S1: Add 1.2 g of 3-chloropropyltriethoxysilane into 100 mL of deionized water, stir evenly, hydrolyze at 55 °C for 3 hours to form a hydrolysis solution; add 2 g of rectorite into 60 mL of absolute ethanol, disperse evenly, and then add the hydrolysis solution into the formed dispersion. After adding, raise the temperature to 65 °C, continuously stir for 4 hours, then cool and discharge, centrifuge out the solid material, and after washing and vacuum drying treatment, obtain rectorite with halogen substituents. Step S2: Add 1.8 g of rectorite with halogen substituents into N,N-dimethylformamide, disperse evenly by ultrasonic wave, then add 4.5 g of (3,5-dihydroxyadamantan-1-yl) methacrylate and a 20% sodium hydroxide aqueous solution by mass fraction. After adding, stir well, then control the temperature at 75 °C, carry out heat preservation treatment for 3 hours, continue to add 7.3 g of halogen-terminated polyethylene glycol, and further raise the temperature to 95 °C. After continuously carrying out heat preservation polymerization for 16 hours, cool and discharge to obtain the rectorite modifier.

[0023] Weigh 0.3 g of the rectorite modified material as the titration test sample, and test the unsaturation value of the sample according to the iodometric method. Use a standard sodium thiosulfate solution with a concentration of 0.1 mol / L for the test. The test results show that the unsaturation value of the sample is 5.847 mmol / g. It can be inferred that the unsaturated functional groups are mainly provided by the macromolecular polymeric substances modified on the surface of rectorite.

[0024] The preparation method of halogen-terminated polyethylene glycol is as follows: Add 2.5 g of polyethylene glycol with a molecular weight of 200 to tetrahydrofuran, start stirring, and after forming a homogeneous solution, place it in an ice bath environment. Then add 2.6 g of 2-chloroethyl isocyanate and 0.1 g of dibutyltin dilaurate to the solution. After adding, remove the ice bath and keep it at 65 °C for 6 h, then evaporate to remove the solvent and collect the product to obtain halogen-terminated polyethylene glycol. Example 2

[0025] A high-strength and high-hardness acrylic composite board, comprising the following raw materials in parts by weight: 70 parts of methyl methacrylate, 0.3 part of initiator benzoyl peroxide, 4 parts of rectorite modified material, 0.6 part of defoaming agent dimethyl silicone oil; The preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator benzoyl peroxide to a polymerization kettle. After adding, start stirring. After forming a homogeneous solution, start heating and maintain the temperature at 80 °C for 40 min of heat preservation pre-polymerization. Stop heating and wait for it to cool naturally to form a prepolymer. Step 2: Add the rectorite modified material and defoaming agent dimethyl silicone oil to the prepolymer, stir and disperse evenly, then let it stand for 15 min. Then pour it into a mold, keep it at 55 °C for 5 h, then keep it at 75 °C for 1 h, and finally keep it at 95 °C for 30 min, and demold to obtain the acrylic composite board. Example 3

[0026] A high-strength and high-hardness acrylic composite board, comprising the following raw materials in parts by weight: 80 parts of methyl methacrylate, 0.5 part of initiator benzoyl peroxide, 4.5 parts of rectorite modified material, 1 part of defoaming agent dimethyl silicone oil; The preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator benzoyl peroxide to a polymerization kettle. After adding, start stirring. After forming a homogeneous solution, start heating and maintain the temperature at 82 °C for 30 min of heat preservation pre-polymerization. Stop heating and wait for it to cool naturally to form a prepolymer. Step 2: Add the rectorite modified material and the defoamer dimethyl silicone oil to the prepolymer. After stirring and dispersing evenly, let it stand for 10 min, then pour it into a mold, keep it warm at 60 °C for 1 h, then keep it warm at 80 °C for 1 h, and finally keep it warm at 100 °C for 20 min, and demold to obtain the acrylic composite board.

[0027] Comparative Example 1 A high-strength and high-hardness acrylic composite board, comprising the following raw materials in parts by weight: 70 parts of methyl methacrylate, 0.3 part of initiator benzoyl peroxide, 4 parts of rectorite, 0.6 part of defoamer dimethyl silicone oil; The preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator benzoyl peroxide to a polymerization kettle. After adding, start stirring. When a uniform solution is formed, start heating, maintain the temperature at 80 °C, keep it warm and pre-polymerize for 40 min, stop heating, and wait for it to cool naturally to form a prepolymer; Step 2: Add rectorite and defoamer dimethyl silicone oil to the prepolymer. After stirring and dispersing evenly, let it stand for 15 min, then pour it into a mold, keep it warm at 55 for 5 h, then keep it warm at 75 °C for 1 h, and finally keep it warm at 95 °C for 30 min, and demold to obtain the acrylic composite board.

[0028] Comparative Example 2 A high-strength and high-hardness acrylic composite board, comprising the following raw materials in parts by weight: 70 parts of methyl methacrylate, 0.3 part of initiator benzoyl peroxide, 0.6 part of defoamer dimethyl silicone oil; The preparation method of the acrylic composite board comprises the following steps: Step 1: Add methyl methacrylate and initiator benzoyl peroxide to a polymerization kettle. After adding, start stirring. When a uniform solution is formed, start heating, maintain the temperature at 80 °C, keep it warm and pre-polymerize for 40 min, stop heating, and wait for it to cool naturally to form a prepolymer; Step 2: Add defoamer dimethyl silicone oil to the prepolymer. After stirring and dispersing evenly, let it stand for 15 min, then pour it into a mold, keep it warm at 55 for 5 h, then keep it warm at 75 °C for 1 h, and finally keep it warm at 95 °C for 30 min, and demold to obtain the acrylic composite board.

[0029] Performance testing Make the boards in the examples and comparative examples into various test samples and conduct various performance tests:

[0030] Among them, the reference standard for tensile property testing is GB / T 1040.1-2018; the reference standard for impact property is GB / T 1843-2008; and the hardness test is carried out with reference to GB / T 2411-2008.

[0031] The test results show that the acrylic composite board prepared by adding rectorite modifier has higher strength and hardness. When directly using rectorite as an additive, due to the lack of macromolecular polymer substances, there are compatibility problems between it and acrylic itself, making it difficult to fully exert its own advantages, and it is also impossible to utilize the cross-linking of macromolecular polymer substances with acrylic molecular chains, so the hardness also decreases significantly.

[0032] In this article, specific examples are used to elaborate on the principle and implementation method of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of this invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A high-strength and high-hardness acrylic composite board, characterized in that, It includes raw materials in the following parts by weight: 65 - 80 parts of methyl methacrylate, 0.2 - 0.5 part of initiator, 2 - 4.5 parts of rectorite modifier, 0.5 - 1 part of defoamer.

2. The high-strength and high-hardness acrylic composite board according to claim 1, wherein The preparation method of the acrylic composite board includes the following steps: Step 1: Add methyl methacrylate and initiator into a polymerization kettle. After adding, start stirring. When a homogeneous solution is formed, start heating and maintain the temperature at 80 - 82 °C for 30 - 60 minutes of heat preservation pre-polymerization. Then stop heating and wait for it to cool naturally to form a prepolymer. Step 2: Add the rectorite modifier and defoamer to the prepolymer. After stirring and dispersing evenly, let it stand for 10 - 20 minutes. Then pour it into a mold and carry out heat preservation treatment at 50 - 60 °C for 1 - 3 hours, then at 70 - 80 °C for 1 - 2 hours, and finally at 90 - 100 °C for 20 - 40 minutes. Demold to obtain the acrylic composite board.

3. A high-strength and high-hardness acrylic composite board according to claim 1, characterized in that The preparation method of the rectorite modifier includes the following steps: Step S1: Use a silane coupling agent to carry out surface modification on rectorite to obtain rectorite containing halogen substituents. Step S2: Use (3,5-dihydroxyadamantan-1-yl) methacrylate as a linker and halogen-terminated polyethylene glycol as a chain extender. Under the action of a catalyst, carry out alternating connection polymerization on the surface of rectorite containing halogen substituents to obtain the rectorite modifier.

4. The high-strength and high-hardness acrylic composite board according to claim 3, characterized in that, In step S1, the silane coupling agent is any one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane or 3-bromopropyltriethoxysilane.

5. A high-strength and high-hardness acrylic composite sheet according to claim 3, characterized in that, In step S2, the halogen-terminated polyethylene glycol is prepared by reacting a halogenated modification reagent with polyethylene glycol under the action of a promoter.

6. The high-strength and high-hardness acrylic composite board according to claim 5, characterized in that, The halogenated modification reagent is any one of chloroethyl isocyanate, 3-chloropropyl isocyanate or 2-bromoethyl isocyanate.

7. The high-strength and high-hardness acrylic composite sheet according to claim 5, characterized in that, The molecular weight of the polyethylene glycol is 200 - 600.

8. A high-strength and high-hardness acrylic composite sheet according to claim 5, characterized in that, The promoter is any one of dibutyltin dilaurate, stannous octoate or dibutyltin diacetate.

9. The high-strength and high-hardness acrylic composite sheet according to claim 3, wherein, In step S2, the catalyst is an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.

10. A high-strength and high-hardness acrylic composite sheet according to claim 1, characterized in that The initiator is benzoyl peroxide or diisopropylbenzene peroxide; the defoamer is dimethyl silicone oil.

Images