A modified transparent polymethyl methacrylate composite material and a preparation method thereof
By adding aluminate coupling agent NXH-821 to polymethyl methacrylate and forming a grafted composite material with nano-titanium dioxide, the problems of low surface hardness and insufficient impact strength of polymethyl methacrylate were solved, and the mechanical properties of the material were improved while its transparency was maintained.
Patent Information
- Application Number
- CN202211692498.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-28
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2042-12-28
AI Technical Summary
Polymethyl methacrylate (PMMA) materials have low surface hardness in transparent plastic applications, making them prone to scratches and lacking sufficient impact resistance, which affects their stability under stress.
By adding aluminate coupling agent NXH-821 to polymethyl methacrylate and grafting it with nano-titanium dioxide, a uniformly dispersed composite material is formed, which enhances the compatibility between resins and improves the tensile strength and impact strength of the material.
It significantly improves the tensile strength and impact strength of polymethyl methacrylate while maintaining high light transmittance and not affecting the transparency of the material.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of materials technology, and in particular to a modified transparent polymethyl methacrylate composite material and its preparation method. Background Technology
[0002] Polymers obtained by polymerizing acrylic acid and its esters are collectively called acrylic resins, and the corresponding plastics are collectively called polyacrylic plastics, among which polymethyl methacrylate (PMMA) is the most widely used. PMMA, commonly known as plexiglass, is the best-quality and most affordable synthetic transparent material to date.
[0003] Polymethyl methacrylate (PMMA) is a thermoplastic resin, a product of the bulk polymerization of methacrylic acid. PMMA is a rigid, colorless, and transparent material with a density of 1.18-1.19 g / cm³, a low refractive index of approximately 1.49, a light transmittance of up to 92%, and a haze of no more than 2%, making it a high-quality organic transparent material. PMMA possesses excellent comprehensive mechanical properties, ranking among the top general-purpose plastics. Its tensile, flexural, and compressive strengths are higher than those of polyolefins, as well as polystyrene and polyvinyl chloride, and can reach the levels of engineering plastics such as polyamide and polycarbonate.
[0004] Generally, polymethyl methacrylate (PMMA) has a tensile strength of 50-77 MPa and a flexural strength of 90-130 MPa, with the upper limits of these properties reaching or even exceeding those of some engineering plastics. However, its elongation at break is only 2%-3%, making its mechanical properties essentially those of a hard and brittle plastic. It is notch-sensitive and prone to cracking under stress, but its fracture surface is not as sharp or jagged as that of polystyrene or ordinary inorganic glass. In other words, PMMA has low surface hardness and is easily scratched. To address these shortcomings in transparent plastic applications, PMMA needs increased surface hardness and impact resistance while maintaining transparency. Summary of the Invention
[0005] The present invention aims to solve the problems existing in the prior art by providing a modified transparent polymethyl methacrylate composite material and its preparation method.
[0006] The objective of this invention is achieved through the following technical solution:
[0007] A modified transparent polymethyl methacrylate composite material is prepared by polymerization reaction from the following components in parts by weight:
[0008]
[0009]
[0010] The methacrylate monomer is an unsaturated carboxylic acid ester that can participate in free radical polymerization, preferably one of methyl methacrylate, ethyl methacrylate, and butyl methacrylate.
[0011] The initiator is preferably an azo initiator, an organic peroxide initiator, or an inorganic peroxide initiator.
[0012] The preferred azo initiators are azobisisobutyronitrile (AIBN) and azobisisoheptane (AIH).
[0013] The preferred organic peroxide initiator is benzoyl peroxide or diethylhexyl peroxide dicarbonate.
[0014] The preferred inorganic peroxide initiator is potassium persulfate, ammonium persulfate, sodium persulfate, etc.
[0015] The nano-titanium dioxide is anatase type with an average particle size of 5-15 nm.
[0016] A method for preparing a modified transparent polymethyl methacrylate composite material includes the following steps:
[0017] Heat 0.05-0.5 parts of aluminate coupling agent NXH-821 to 80-100℃, then spray it evenly onto the surface of 2-8 parts of nano-titanium dioxide. After returning to room temperature, add it to 100 parts of methacrylate monomers, ultrasonically disperse it evenly, then add 0.1-0.8 parts of initiator, mix evenly, and keep at 40℃-70℃ for 10-60 minutes; the prepolymerization process is complete. Raise the temperature to 90-120℃ and continue the reaction for 0.5-5 hours to obtain the modified transparent polymethyl methacrylate composite material.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] In this invention, the melting temperature of the aluminate coupling agent NXH-821 is 52°C. Therefore, an innovative approach is to first heat and melt the aluminate coupling agent NXH-821, allowing it to be uniformly sprayed and dispersed on the surface of nano-titanium dioxide in a liquid state. At high temperature, the inorganic-loving end groups of the aluminate coupling agent NXH-821 react with a large number of hydroxyl groups on the surface of nano-titanium dioxide, thereby forming grafts.
[0020] The polymerization of polymethyl methacrylate (PMMA) is a free radical polymerization process, initiated by free radicals, which causes the molecular chains to grow continuously. The aluminate coupling agent NXH-821, by coupling organic functional groups, can entangle with the molecular chains of PMMA resin, thereby enabling uniform dispersion of nano-titanium dioxide and enhancing compatibility with the resin.
[0021] In this invention, the addition of aluminate coupling agent NXH-821 and anatase titanium dioxide with an average particle size of 5-15 nm significantly improves the tensile strength and impact strength of polymethyl methacrylate, while maintaining a high level of light transmittance without affecting transparency. Detailed Implementation
[0022] The present invention will be further described below with reference to specific embodiments (but not limited to the embodiments described herein):
[0023] In each embodiment, the methacrylate monomer used is methyl methacrylate, manufactured by Jinan Chuangshi Chemical Co., Ltd.
[0024] The initiators selected were benzoyl peroxide and azobisisobutyronitrile (AIBN), manufactured by Shandong Guohua Chemical Co., Ltd.
[0025] In Examples 1-5 and Comparative Examples 6-7, the nano-titanium dioxide was anatase with an average particle size of 10 nm. The nano-titanium dioxide in all examples and comparative examples was manufactured by Ningbo Jiwei Nanomaterials Co., Ltd.
[0026] The aluminate coupling agent NXH-821 and the silane coupling agent KH550 are manufactured by Jinan Baite New Materials Co., Ltd.
[0027] The manufacturer of the aluminate coupling agent LS-821 is Kunshan Shengan Biotechnology Co., Ltd.
[0028] The testing conditions for the products prepared in each embodiment and comparative example are as follows:
[0029] The tensile specimen has the dimensions of (170.0±5.0)mm*(13.0±0.5)mm*(3.2±0.2)mm, a tensile rate of 5mm / min, and a test standard of GB / T 1040.
[0030] The cantilever beam impact strength specimen used is (125.0±5.0)mm*(13.0±0.5)mm*(3.2±0.2)mm, and the test standard is GB / T 1843.
[0031] The standard for light transmittance testing is GB / T 2680-94.
[0032] Example 1
[0033] 0.1 parts of aluminate coupling agent NXH-821 were heated to 90°C and then uniformly sprayed onto the surface of 3 parts of nano-titanium dioxide. After returning to room temperature, it was added to 100 parts of methyl methacrylate, ultrasonically dispersed, and then 0.2 parts of initiator were added. After mixing evenly, it was kept at 65°C for 20 minutes. After the prepolymerization process was completed, the temperature was raised to 110°C and the reaction was continued for 1 hour to obtain a modified transparent polymethyl methacrylate composite material.
[0034] Example 2
[0035] 0.4 parts of aluminate coupling agent NXH-821 were heated to 85°C and then uniformly sprayed onto the surface of 7 parts of nano-titanium dioxide. After returning to room temperature, it was added to 100 parts of methyl methacrylate, ultrasonically dispersed, and then 0.4 parts of initiator were added. After mixing evenly, it was kept at 60°C for 25 minutes. After the prepolymerization process was completed, the temperature was raised to 100°C and the reaction was continued for 1.5 hours to obtain the modified transparent polymethyl methacrylate composite material.
[0036] Example 3
[0037] 0.3 parts of aluminate coupling agent NXH-821 were heated to 95°C and then uniformly sprayed onto the surface of 6 parts of nano-titanium dioxide. After returning to room temperature, it was added to 100 parts of methyl methacrylate, ultrasonically dispersed, and then 0.5 parts of initiator were added. After mixing evenly, the mixture was kept at 55°C for 45 minutes, thus ending the prepolymerization process. The temperature was then raised to 95°C, and the reaction was continued for 2 hours to obtain a modified transparent polymethyl methacrylate composite material.
[0038] Example 4
[0039] 0.3 parts of aluminate coupling agent NXH-821 were heated to 95°C and then uniformly sprayed onto the surface of 4 parts of nano-titanium dioxide. After returning to room temperature, it was added to 100 parts of methyl methacrylate, ultrasonically dispersed, and then 0.5 parts of initiator were added. After mixing evenly, the mixture was kept at 60°C for 40 minutes, thus ending the prepolymerization process. The temperature was then raised to 100°C, and the reaction was continued for 1.5 hours to obtain the modified transparent polymethyl methacrylate composite material.
[0040] Example 5
[0041] 0.3 parts of aluminate coupling agent NXH-821 were heated to 95°C and then uniformly sprayed onto the surface of 5 parts of nano-titanium dioxide. After returning to room temperature, it was added to 100 parts of methyl methacrylate, ultrasonically dispersed, and then 0.5 parts of initiator were added. After mixing evenly, the mixture was kept at 60°C for 40 minutes, thus ending the prepolymerization process. The temperature was then raised to 100°C, and the reaction was continued for 1.5 hours to obtain the modified transparent polymethyl methacrylate composite material.
[0042] Comparative Example 1
[0043] In this comparative example, the coupling agent is the titanate coupling agent TC-WT, which replaces the coupling agent NXH-821 in Example 5 in equal amounts, and all other process parameters are the same.
[0044] Comparative Example 2
[0045] In this comparative example, the coupling agent is aluminate coupling agent LS-821, which replaces the coupling agent NXH-821 in Example 5 in equal amounts. All other process parameters are the same.
[0046] Comparative Example 3
[0047] In this comparative example, the coupling agent is silane coupling agent KH-550, which replaces the coupling agent NXH-821 in Example 5 in equal amounts. All other process parameters are the same.
[0048] Comparative Example 4
[0049] In this comparative example, the nano-titanium dioxide is anatase with an average particle size of 3 nm; it is used to replace the nano-titanium dioxide (anatase with an average particle size of 10 nm) in Example 5 in equal amounts, and all other process parameters are the same.
[0050] Comparative Example 5
[0051] In this comparative example, the nano-titanium dioxide is anatase with an average particle size of 20 nm; it is used to replace the nano-titanium dioxide in Example 5 in equal amounts, and all other process parameters are the same.
[0052] Comparative Example 6
[0053] In this comparative example, nano-titanium dioxide (rutile type, average particle size 10 nm) was used to replace the nano-titanium dioxide in Example 5 in equal amounts, and all other process parameters were the same.
[0054] The performance test results are shown in Table 1.
[0055] Table 1 Performance Test Results
[0056]
[0057] According to the test results, it can be seen that after adding aluminate coupling agent NXH-821 and anatase titanium dioxide with an average particle size of 10nm, the tensile strength and impact strength of polymethyl methacrylate are significantly improved, and the light transmittance can be maintained at a high level without affecting the transparency.
[0058] Compared to Example 5, Comparative Examples 1-3 showed a significant decrease in tensile strength, impact strength, and light transmittance. In Comparative Example 4, the average particle size of the nanoparticles was too small. Although the manufacturer had made some adjustments to the dispersion of the nanoparticles, significant agglomeration may have occurred in the polymethyl methacrylate matrix, leading to a decline in various properties. In Comparative Example 5, the average particle size of the added nano-titanium dioxide was too large, resulting in a gradual decrease in mechanical properties and a significant impact on transparency. In Comparative Example 6, rutile titanium dioxide with an average particle size of 10 nm, when added to the polymethyl methacrylate matrix, exhibited mechanical properties similar to anatase titanium dioxide, but it severely affected the transparency of the matrix.
[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A modified transparent polymethyl methacrylate composite material, characterized in that: It is prepared by polymerization reaction of the following components in parts by weight: 100 parts of methacrylate monomers Initiator 0.1-0.8 parts, 2-8 parts of nano titanium dioxide The aluminate coupling agent NXH-821 is 0.05-0.5 parts; The methacrylate monomers are unsaturated carboxylic acid esters that can participate in free radical polymerization; The nano-titanium dioxide is anatase type with an average particle size of 5-15 nm. The aluminate coupling agent NXH-821 is first heated to melt, and then sprayed and dispersed evenly on the surface of nano-titanium dioxide in a liquid state.
2. The modified transparent polymethyl methacrylate composite material according to claim 1, characterized in that: The methacrylate monomers are methyl methacrylate, ethyl methacrylate, or butyl methacrylate.
3. The modified transparent polymethyl methacrylate composite material according to claim 1, characterized in that: The initiator is an azo initiator, an organic peroxide initiator, or an inorganic peroxide initiator.
4. The modified transparent polymethyl methacrylate composite material according to claim 3, characterized in that: The azo initiator is azobisisobutyronitrile or azobisisoheptanenitrile; The organic peroxide initiator is benzoyl peroxide or diethylhexyl percarbonate; The inorganic peroxide initiator is potassium persulfate, ammonium persulfate, or sodium persulfate.
5. A method for preparing a modified transparent polymethyl methacrylate composite material according to any one of claims 1-4, characterized in that: Includes the following steps: Heat 0.05-0.5 parts of aluminate coupling agent NXH-821 to 80-100℃, then spray it evenly onto the surface of 2-8 parts of nano-titanium dioxide. After returning to room temperature, add it to 100 parts of methacrylate monomers, disperse it evenly by ultrasonication, then add 0.1-0.8 parts of initiator, mix evenly, and keep it at 40℃-70℃ for 10-60 minutes. After the prepolymerization process is completed, raise the temperature to 90-120℃ and continue the reaction for 0.5-5 hours to obtain the modified transparent polymethyl methacrylate composite material.