An optically transparent high-toughness PMMA composite and its preparation method
By adding PMMA-b-PCholMA block copolymer and nucleating agent to PMMA, an optically transparent high-toughness PMMA composite was prepared, which solved the problem of low toughness of PMMA material and achieved a balance between high toughness and transparency, thus broadening the application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING INST OF TECH
- Filing Date
- 2023-11-17
- Publication Date
- 2026-07-03
AI Technical Summary
Existing PMMA materials have limited applications due to their low toughness and fragility, and existing toughening methods can affect properties such as transparency, thermal stability, and glass transition temperature.
An optically transparent, high-toughness PMMA composite was prepared in one step by heating and mixing PMMA-b-PCholMA block copolymer, antioxidant, and nucleating agent in a polar solvent to form block copolymer columnar micelles.
It significantly improves the toughness and impact strength of PMMA while maintaining high transparency and thermal stability, thus broadening the application range of PMMA. Moreover, the preparation method is simple and easy to industrialize.
Smart Images
Figure CN117362883B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to an optically transparent, high-toughness PMMA composite and its preparation method. Background Technology
[0002] Polymethyl methacrylate (PMMA) is a polymer with a glass transition temperature (Tg) of 105°C. Due to its excellent transparency, high modulus, low cost, and ease of processing, it is widely used as a substitute for glass, hence also known as acrylic or plexiglass. However, its elongation at break is only 2%–3%, making it a hard and brittle material. The low ductility and fragility of ordinary PMMA limit its further applications. Therefore, modification of PMMA is necessary.
[0003] Numerous methods have been reported to significantly improve the toughness of PMMA. Generally, this is achieved by adding solid particulate fillers to the PMMA matrix. The main fillers used in PMMA toughening modification include core-shell modifiers, nanoparticles, inorganic rigid materials, and filler particles with introduced cross-linked structures or interpenetrating networks. While these solid particulate fillers can significantly improve PMMA toughness, they also reduce the transparency, thermal stability, and glass transition temperature of PMMA materials due to poor compatibility between most toughening agent components and the PMMA matrix, uneven filler dispersion, and complex preparation methods. A significant decrease in the glass transition temperature narrows the processing and service temperature range of PMMA, limiting its applications in various fields. Summary of the Invention
[0004] To address the issues of complex PMMA material preparation methods that lead to reduced transparency, thermal stability, and glass transition temperature, this invention provides an optically transparent high-toughness PMMA composite and its preparation method, which significantly improves the toughness and other mechanical properties of PMMA without significantly affecting its other physical properties.
[0005] To achieve the above objectives, the present invention provides a method for preparing an optically transparent, high-toughness PMMA composite, wherein PMMA-... is prepared in a mass ratio of 1:(60~100):(0.2~0.5):(0.1~0.4). b - PCholMA block copolymer, PMMA powder, antioxidant and nucleating agent are dispersed in a polar solvent, heated and then cooled to obtain the final product.
[0006] PMMA- b-PCholMA block copolymer is poly(methyl methacrylate)-block-poly(cholesterol methacryloyloxyethyl carbonate) PMMA- b -PcholMA, its structural formula is:
[0007]
[0008] Where m is the degree of polymerization of PMMA, and the value of m ranges from 100 to 200; n is the degree of polymerization of PCholMA, and its value ranges from 10 to 50.
[0009] The molar ratio of polymethyl methacrylate to polycholestyrene methacryloyloxyethyl carbonate is 1 to 10:1; preferably, the molar ratio of polymethyl methacrylate to polycholestyrene methacryloyloxyethyl carbonate is 7:1.
[0010] PMMA- b The role of PCholMA block copolymer micelles: as toughening agents to improve the toughness and impact strength of PMMA materials.
[0011] The role of antioxidants: to prevent oxidation of PMMA materials and block copolymers, and at the same time to stabilize the solution.
[0012] The role of nucleating agents: to promote the nucleation of block copolymers and improve the transparency and processability of PMMA.
[0013] This invention prepares a PMMA composite containing block copolymer columnar micelles in a one-step process. By adjusting the solvent polarity, columnar micelles of different lengths can be obtained. The toughness of the PMMA composite containing micelles of different lengths is significantly improved. Furthermore, the toughened PMMA retains high transparency. In addition, while significantly improving the mechanical properties of PMMA such as toughness and impact strength, it does not significantly affect the physical properties of PMMA such as thermal stability, refractive index, Vicat softening point, and glass transition temperature.
[0014] Preferably, the PMMA- b -PCholMA block copolymers have a molecular weight of 20,000~35,000 g / mol.
[0015] Preferably, the PMMA- b The concentration of -PCholMA block copolymer in polar solvents is 0.1~20 mg / mL.
[0016] Preferably, the PMMA powder has a particle size of 100~150 μm.
[0017] Preferably, the antioxidant is selected from one or more of antioxidant A-612, antioxidant AO-60, and antioxidant 2112.
[0018] Preferably, the nucleating agent is selected from at least one of bis(phenylmethylene)sorbitol, aluminum benzoate, sodium β-naphthoate, and butylene terephthalate.
[0019] More preferably, the polar solvent is N,N-dimethylformamide or a mixed solvent of N,N-dimethylformamide and o-dichlorobenzene in a volume ratio of (3~4):1, wherein the N,N-dimethylformamide is a block copolymer PMMA- b - PCholMA is a selective solvent, while o-dichlorobenzene is used as a block copolymer PMMA- b - The good solvent of PCholMA can control the length of columnar micelles.
[0020] The heating temperature is 100~140℃, and the heating time is 30~75 min, which is suitable for block copolymers PMMA- b -PCholMA is assembled into columnar micelles.
[0021] The cooling refers to cooling to room temperature.
[0022] A second aspect of the present invention provides an optically transparent, high-toughness PMMA composite prepared by the above-described preparation method.
[0023] PMMA in the complex b - The length of the PCholMA block copolymer micelles is 100~2000 nm. The columnar micelles with lengths within this range after assembly have a good toughening effect on PMMA, and the toughness of the PMMA composite is related to the length of the columnar micelles.
[0024] Through the above technical solution, the present invention achieves the following beneficial effects:
[0025] 1. This invention prepares a PMMA composite containing block copolymer columnar micelles using a one-step method. By adjusting the solvent polarity, columnar micelles of different lengths can be obtained. The toughness of PMMA composites containing micelles of different lengths is significantly improved. Furthermore, the toughened PMMA retains high transparency. In addition, while significantly improving the mechanical properties of PMMA such as toughness and impact strength, it does not significantly affect the physical properties of PMMA such as thermal stability, refractive index, Vicat softening point, and glass transition temperature, thus broadening the application range of PMMA composites.
[0026] 2. The preparation method of this invention is simple, easy to control, and conducive to industrial production, giving it a great advantage for future market applications. Attached Figure Description
[0027] Figure 1 These are transmission electron microscopy images of the PMMA composites prepared in Examples 1-3 of this invention, where (a) to (c) correspond to Examples 1-3 respectively. Detailed Implementation
[0028] The specific embodiments of the present invention will be described in detail below with reference to examples. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0029] Example 1
[0030] block copolymer PMMA- b A solution of 90 mg PCholMA, 18 mg antioxidant A-612, 9 mg nucleating agent bis(phenylmethylene)sorbitol, and 5.4 g PMMA powder was dispersed in 9 mL of N,N-dimethylformamide solvent. This solution was then heated to 100 °C while maintaining a stirring rate of 150 rpm for approximately 1 h. After the PMMA powder was completely dissolved, the viscous solution was cast into a polytetrafluoroethylene mold and dried under vacuum at 50 °C for 72 hours to ensure complete solvent removal. The resulting product is the PMMA complex.
[0031] After cooling and drying, a small amount of PMMA composite was taken and dispersed in N,N-dimethylformamide. The columnar micelles of different lengths had a significant impact on the toughness of PMMA. TEM measurements showed that the average length of the block copolymer columnar micelles was 239 nm, and the length distribution coefficient was 1.03 (e.g., ...). Figure 1 As shown in (a), this indicates that the obtained columnar micelles have good uniformity in length.
[0032] Example 2
[0033] block copolymer PMMA- b PCholMA 120 mg, antioxidant AO-60 30 mg, nucleating agent aluminum benzoate 24 mg, and PMMA powder 9 g were dispersed in 9 mL of N,N-dimethylformamide and o-dichlorobenzene solvent (volume ratio 4:1) to form a solution. This solution was then heated to 110 °C, with stirring maintained at 100 rpm for approximately 3 h. After the PMMA powder was completely dissolved, the viscous solution was cast into a polytetrafluoroethylene mold and dried under vacuum at 50 °C for 72 hours to ensure complete solvent removal. The resulting product is the PMMA composite.
[0034] After cooling and drying, a small amount of the PMMA complex was taken and dispersed in N,N-dimethylformamide. TEM analysis showed that the average length of the columnar micelles of the block copolymer was 761 nm, and the length distribution coefficient was 1.02 (e.g., ...). Figure 1 (as shown in (b)).
[0035] Example 3
[0036] block copolymer PMMA- b A solution was prepared by dispersing 90 mg of PCholMA, 45 mg of antioxidant AO-60, 18 mg of nucleating agent sodium β-naphthylcarboxylate, 18 mg of butylene terephthalate, and 9 g of PMMA powder in 9 mL of N,N-dimethylformamide and o-dichlorobenzene solvent (volume ratio 3:1). The solution was then heated to 140°C with stirring at 120 rpm for approximately 2 hours until the PMMA powder was completely dissolved. The resulting viscous solution was then cast into a polytetrafluoroethylene mold and dried under vacuum at 50°C for 72 hours to ensure complete solvent removal. The resulting product is the PMMA composite.
[0037] After cooling and drying, a small amount of the PMMA complex was taken and dispersed in N,N-dimethylformamide. TEM analysis showed that the average length of the columnar micelles of the block copolymer was 1386 nm, and the length distribution coefficient was 1.02 (e.g., ...). Figure 1 (as shown in (c)).
[0038] Comparative Example 1
[0039] The other conditions are the same as in Example 1, except that the nucleating agent is omitted.
[0040] Comparative Example 2
[0041] The other conditions are the same as in Example 1, except that the antioxidant is omitted.
[0042] The obtained PMMA toughened samples were cut into dumbbell-shaped specimens and unnotched impact specimens using a cutting tool. Simultaneously, equal amounts of PMMA were used to prepare dumbbell specimens and notched impact blank samples using a casting molding method.
[0043] The samples obtained in Examples 1-3 and the comparative example were tested for tensile strength and elongation at break using a universal tensile testing machine according to GB / T528-2009. The unnotched impact strength was tested using a simply supported beam pendulum impact tester according to GB / T1043-2008. The PMMA composite and the comparative example were tested for relevant physicochemical properties using a TGA, DSC, UV-Vis spectrophotometer, and refractometer.
[0044] The test results are shown in Table 1.
[0045] Table 1. Test results of the examples and comparative examples.
[0046]
[0047] As can be seen from Table 1, compared with the pure PMMA sample, the PMMA composite containing block copolymer columnar micelles disclosed in this invention has higher toughness, impact strength and light transmittance. At the same time, it does not significantly affect other physical properties of PMMA (including the glass transition temperature, thermal decomposition temperature, softening point, etc. of PMMA).
[0048] Compared with Comparative Example 1 (without nucleating agent) and Comparative Example 2 (without antioxidant), the PMMA composites prepared in the examples have better toughness and impact resistance.
[0049] The preferred embodiments of the present invention have been described in detail above with reference to the examples. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
[0050] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.
[0051] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.
Claims
1. A method for preparing an optically transparent, high-toughness PMMA composite, characterized in that, PMMA with a mass ratio of 1:(60~100):(0.2~0.5):(0.1~0.4) b -PCholMA block copolymer, PMMA powder, antioxidant and nucleating agent are dispersed in a polar solvent, heated and then cooled to obtain the product; the PMMA- b The molar ratio of polymethyl methacrylate to polycholestyrene methacryloyloxyethyl carbonate in the PCholMA block copolymer is 1~10:1, wherein the PMMA- b The concentration of the PCholMA block copolymer in the polar solvent is 0.1~20 mg / mL. The antioxidant is selected from one or more of antioxidant A-612, antioxidant AO-60, and antioxidant 2112. The nucleating agent is selected from at least one of bis(phenylmethylene)sorbitol, aluminum benzoate, sodium β-naphthoate, and butylene terephthalate. The polar solvent is N,N-dimethylformamide or a mixed solvent of N,N-dimethylformamide and o-dichlorobenzene in a volume ratio of (3~4):
1. The heating temperature is 100~140℃ and the heating time is 30~75 min.
2. The preparation method according to claim 1, characterized in that, The PMMA- b -PCholMA block copolymers have a molecular weight of 20,000~35,000 g / mol.
3. The preparation method according to claim 1, characterized in that, The PMMA powder has a particle size of 100~150 μm.
4. An optically transparent, high-toughness PMMA composite prepared by any one of claims 1 to 3.
5. The PMMA composite according to claim 4, characterized in that, The PMMA complex contains PMMA- b The length of the columnar micelles of the -PCholMA block copolymer is 100~2000 nm.