Structure and function integrated PMMA (polymethyl methacrylate) composite material as well as preparation method and application thereof

Abstract

The invention provides a structure and function integrated PMMA (polymethyl methacrylate) composite material as well as a preparation method and application thereof, and belongs to the technical field of thermoplastic composite materials. The preparation method comprises the following steps: mixing an acrylate core-shell copolymer and methyl methacrylate according to a mass ratio of (1-20): 100 to obtain a resin solution; respectively adding a functional filler and an initiator which account for 0.1-20% of the mass of the resin solution into the resin solution, and mixing to obtain a stable resin solution; after the reinforced fiber material and the stable resin liquid are compounded, an in-situ bulk polymerization reaction is initiated, and the structure and function integrated PMMA composite material is prepared. After the resin liquid added with the functional filler is compounded with the reinforcing material to form the composite material, the PMMA composite material is subjected to in-situ bulk polymerization reaction, so that the obtained composite material has excellent mechanical properties and functionality, and finally, the structure and function integrated PMMA thermoplastic composite material is formed.

Description

Technical Field

[0001] This invention belongs to the field of thermoplastic composite materials technology, and particularly relates to a PMMA composite material with integrated structure and function, its preparation method and application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Structural-functional integrated composite materials refer to materials or structures formed from materials that, while bearing mechanical loads, possess one or more specific physical, chemical, or biological functions. For example, in the wind power sector, the main load-bearing structural components of wind turbines are required to withstand mechanical loads while also possessing properties such as lightning protection, electrical conductivity, and weather resistance. Currently, thermosetting composite materials are mainly used in fields with extremely high requirements for structural-functional integration, such as wind power and transportation. While they offer excellent overall performance, their recycling and reprocessing are difficult, and they also put pressure on the environment.

[0004] Thermoplastic composites, especially those based on polymethyl methacrylate (PMMA), possess excellent weather resistance, processability, and recyclability. However, their inherent brittleness and limited functionality restrict their application in high-end structural components requiring both load-bearing capacity and special functions (such as thermal conductivity, electrical conductivity, and intelligent color regulation). Functional properties or improved toughness are typically achieved by adding fillers or blending with other components. However, in traditional melt blending methods, the high melt viscosity of PMMA resin hinders the uniform dispersion of other components within the PMMA, easily leading to internal agglomeration and defects, resulting in decreased mechanical properties and unstable functionality. Furthermore, when composited with fiber reinforcements (such as carbon fiber and glass fiber) to prepare high-strength structural components, the high melt viscosity of PMMA resin severely impairs the full wetting of the fiber bundles, easily leading to poor interfacial bonding in the composite material and becoming the ultimate source of failure.

[0005] To address the issues of filler dispersion and poor thermoplastic resin wettability, existing technologies often employ in-situ bulk polymerization. This involves partially polymerizing MMA monomers to form a prepolymer of a certain viscosity, which is then added as filler or fiber composites to improve filler dispersion stability and meet the necessary resin viscosity requirements for fiber composites. However, this method suffers from drawbacks such as difficulty in process control, poor repeatability, narrow operating window, low production efficiency, and impact on the final material properties. These are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a structurally and functionally integrated PMMA composite material, its preparation method, and its application. This invention aims to overcome the defects of existing in-situ prepolymerization methods in the preparation of filled or fiber-reinforced thermoplastic resin composite materials, such as difficulty in process control and poor repeatability. This method abandons the traditional approach of partially polymerizing MMA monomers and instead adopts a technical route of directly dissolving pre-synthesized copolymers in MMA monomers.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing a structurally and functionally integrated PMMA composite material, comprising the following steps: S1. Mix acrylate core-shell copolymers with a weight average molecular weight of 500,000 to 2,500,000 g / mol and methyl methacrylate in a mass ratio of (1 to 20): 100 to obtain a resin solution. S2. Add functional fillers and initiators, accounting for 0.1~10% by mass of the resin solution, to the above resin solution respectively, and mix to obtain a stable resin solution; S3. After the reinforcing fiber material is combined with the stabilized resin liquid, an in-situ bulk polymerization reaction is initiated to prepare the structure-functional integrated PMMA composite material.

[0008] Secondly, the structurally and functionally integrated PMMA composite material prepared by the above-mentioned method is a PMMA composite material with integrated structure and function.

[0009] Thirdly, the applications of the aforementioned integrated structural and functional PMMA composite materials include next-generation high-end industrial and consumer product fields such as transportation, equipment, new energy, and consumer goods, which have extreme, composite, and intelligent requirements for material performance.

[0010] The beneficial effects of this invention are as follows: This invention utilizes a core-shell structured acrylate copolymer (ACR) directly dissolved in methyl methacrylate (MMA) to form a resin solution with a predetermined viscosity. This facilitates the dispersion and stability of various functional fillers in the resin solution, forming a stable solution or suspension. It also meets the resin viscosity requirements of various composite material molding processes, which is beneficial for composites with reinforcing materials. The method replaces chemical prepolymerization with physical thickening, offering significant advantages in simplifying the process, improving controllability, enhancing dispersion, and reducing production costs. It provides a more reliable and efficient route for the preparation of high-performance PMMA-based composite materials. By combining the resin solution with functional fillers and reinforcing materials to form a composite material, PMMA undergoes in-situ bulk polymerization. The resulting composite material possesses excellent mechanical properties while also exhibiting functionality, ultimately forming a structurally and functionally integrated PMMA thermoplastic composite material. This material possesses recyclability and reprocessability not found in thermosetting composites, and has broad application prospects in various sectors of the national economy, including transportation and wind power generation. Detailed Implementation

[0011] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0012] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0013] A specific embodiment of the present invention provides a method for preparing a structurally and functionally integrated PMMA composite material, comprising the following steps: S1. Mix acrylate core-shell copolymers with a weight average molecular weight of 500,000 to 2,500,000 g / mol and methyl methacrylate in a mass ratio of (1 to 20): 100 to obtain a resin solution. S2. Add functional fillers and initiators, accounting for 0.1~10% by mass of the resin solution, to the above resin solution respectively, and mix to obtain a stable resin solution; S3. After the reinforcing fiber material is combined with the stabilized resin liquid, an in-situ bulk polymerization reaction is initiated to prepare the structure-functional integrated PMMA composite material.

[0014] In the above method, acrylate core-shell copolymer (ACR) is added to methyl methacrylate to dissolve and obtain a resin solution with a set viscosity. Then, fillers and initiators are added, and after being compounded with reinforcing fibers, in-situ bulk polymerization is carried out to obtain a dense composite material with good wettability between the resin and the reinforcing fibers.

[0015] Compared to the method of partial polymerization of MMA monomers first, the above scheme directly uses existing copolymers dissolved in MMA monomers. The viscosity of the system can be precisely controlled by adjusting the molecular weight and concentration of the copolymers, which meets the requirements of filler dispersion and composite with reinforcing materials. The process is simple and controllable. At the same time, the copolymer dissolution process is a physical mixing process, which is not easily affected by the fluctuation of reaction conditions and is easy to achieve batch-to-batch consistency. There is no need to perform in-situ prepolymerization to obtain a certain viscosity, which eliminates the prepolymerization reaction and monitoring links and avoids the risks of living polymerization. It can be carried out at room temperature or low temperature without strict temperature control and reaction termination operations. It also has the characteristics of simplified process, shortened production time, and suitable for large-scale preparation.

[0016] Optionally, in S1, the acrylate core-shell copolymer (ACR) has a weight-average molecular weight of 500,000 to 2,500,000 g / mol and is soluble in MMA.

[0017] Optionally, in S1, the viscosity of the resin solution is 50~1000 mPa•s at 25℃; the viscosity of the resin solution is controlled by adjusting the content of the copolymer.

[0018] Optionally, in S2, the functional filler includes one or more of photochromic fillers, thermochromic fillers, electromagnetic wave shielding fillers, radiation shielding fillers, and conductive fillers; used to realize the functionality of the composite material.

[0019] Optionally, in S1, the initiator is a free radical initiator, including one or more of azo initiators, organic peroxide initiators, and redox system initiators.

[0020] Optionally, in S2, the functional filler undergoes surface treatment, and the surface treatment method includes coupling agent modification, polymer coating modification, or surfactant modification; this is used to promote the uniform dispersion of the functional filler in the resin solution and prevent uneven distribution caused by sedimentation.

[0021] Optionally, in S3, the type of reinforcing fiber material includes one or more of glass fiber, carbon fiber, basalt fiber, and plant fiber; used to improve the mechanical properties of the composite material and realize its structural function.

[0022] Optionally, in S3, the reinforcing fiber material is either chopped fiber or continuous fiber cloth; when chopped fiber is used, the reinforcing fiber material is uniformly dispersed in the stabilizing resin liquid; when continuous fiber cloth is used, the continuous fiber cloth is distributed according to a set layup method, and the stabilizing resin liquid impregnates the continuous fiber cloth and is distributed between adjacent continuous fiber cloth layers.

[0023] Optionally, the continuous fiber fabric is one or more of a unidirectional continuous fiber fabric, a two-dimensional laminated structure fabric, or a three-dimensional woven structure fabric; the single layer of the two-dimensional laminated structure fabric is one of plain weave, twill weave, or satin weave; the three-dimensional woven structure fabric is one of three-dimensional four-way, three-dimensional five-way, three-dimensional six-way, or three-dimensional seven-way.

[0024] Optionally, in S3, the composite method includes one of the following: casting, vacuum injection molding, hand lay-up molding, filament winding, or pultrusion molding.

[0025] Optionally, in S3, the initiation method for the in-situ bulk polymerization reaction includes thermal initiation.

[0026] The present invention provides a method for preparing the above-mentioned structurally and functionally integrated PMMA composite material.

[0027] The specific embodiments of the present invention provide an application of the above-mentioned integrated structural and functional PMMA composite material, including the next generation of high-end industrial and consumer product fields such as transportation, equipment, new energy, and consumer products, which have extreme, composite and intelligent requirements for material performance.

[0028] The present invention will be further described below with reference to specific embodiments.

[0029] Example 1 A method for preparing a structurally and functionally integrated PMMA composite material includes the following steps: S1. Take an acrylate core-shell copolymer (ACR) with a weight average molecular weight of 500,000 g / mol, mix it with methyl methacrylate (MMA) at a weight ratio of 15:100, stir at 25°C until completely dissolved to obtain a resin solution, and measure the viscosity of the resin solution to be 411 mPa•s.

[0030] S2. Add photochromic filler to the resin solution at a mass ratio of 5%, and stir for 30 minutes to ensure uniform dispersion of the filler. Add benzoyl peroxide (BPO) and N,N-dimethyl-p-toluidine (DMPT) redox initiation system as initiators at a mass ratio of 1.0% of the resin solution. Stir until homogeneous to form a mixed resin solution. The photochromic filler is surface modified with a silane coupling agent to ensure that the filler forms a stable suspension in the mixed resin solution.

[0031] S3. A unidirectional continuous basalt fiber fabric was selected as the reinforcing fiber material. The reinforcing fiber material was then compounded with a mixed resin solution using a hand lay-up molding method: first, the resin solution was brushed onto the mold, then the basalt fiber fabric was laid down, air bubbles were removed using rollers, and the layers were stacked to the required thickness. The mixture was cured at room temperature for 12 hours, and then cured at 80°C for 1 hour to obtain a structurally and functionally integrated PMMA composite material.

[0032] Tests have shown that the photochromic filler can be uniformly dispersed in the resin solution and the final photochromic PMMA composite material. This material is suitable for high-end applications that require both load-bearing capacity and adaptive functions (dimming, warning, interaction) based on ambient light, such as outdoor applications or applications with variable lighting conditions.

[0033] Example 2 A method for preparing a structurally and functionally integrated PMMA composite material includes the following steps: S1. Take an acrylate core-shell copolymer (ACR) with a weight average molecular weight of 1,000,000 g / mol, mix it with methyl methacrylate (MMA) at a weight ratio of 10:100, stir at 25°C until completely dissolved to obtain a resin solution, and measure the viscosity of the resin solution to be 823 mPa•s.

[0034] S2. Add nano-silica filler to the resin solution at a mass ratio of 2%, stir for 30 minutes to ensure uniform dispersion of the filler. The nano-silica used is surface modified with silane coupling agent to ensure that the filler forms a stable suspension in the mixed resin solution. Add a mixture of azobisisobutyronitrile (ABVN) and dilauryl peroxide (LPO) as an initiator at a mass ratio of 2.0% of the resin solution. Stir evenly to form a mixed resin solution.

[0035] S3. Carbon fiber is selected as the reinforcing fiber material, and the reinforcing fiber material is compounded with the mixed resin liquid by pultrusion molding: First, the mixed resin liquid and fiber material are mixed in the impregnation tank, and then pultruded by heating the mold. The mold temperature is controlled at 100-130℃. Curing is achieved at the same time as pultrusion to obtain a PMMA composite material with integrated structure and function.

[0036] Tests have shown that nano-silica filler can be uniformly dispersed in resin solution and in the final PMMA composite pultrusion bar. This material is suitable for applications requiring high dimensional stability, high mechanical properties, and excellent weather resistance.

[0037] Example 3 A method for preparing a structurally and functionally integrated PMMA composite material includes the following steps: S1. Take an acrylate core-shell copolymer (ACR) with a weight average molecular weight of 2,000,000 g / mol, mix it with methyl methacrylate (MMA) at a weight ratio of 2:100, stir at 25°C until completely dissolved to obtain a resin solution, and measure the viscosity of the resin solution to be 169 mPa•s.

[0038] S2. Add thermochromic filler to the resin solution at a mass ratio of 0.5%, stir for 30 minutes to ensure uniform dispersion of the filler; add benzoyl peroxide (BPO) as an initiator at a mass ratio of 1.0%, and stir until uniform to form a mixed resin solution.

[0039] S3. Glass fiber three-dimensional woven fabric is selected as the reinforcing fiber material. The reinforcing fiber material is combined with the mixed resin liquid by vacuum injection molding: first, the glass fiber three-dimensional woven fabric is laid in the mold, then the resin liquid is injected, the air bubbles are removed by vacuuming, and finally it is cured at 60°C for 6 hours to obtain a structural and functional integrated PMMA composite material.

[0040] Tests have shown that the thermochromic filler can be uniformly dispersed in the resin solution and in the final thermochromic PMMA composite material. This material is suitable for applications that require lightweight, high strength, and visualization of temperature changes.

[0041] Example 4 A method for preparing a structurally and functionally integrated PMMA composite material includes the following steps: S1. Take an acrylate core-shell copolymer (ACR) with a weight average molecular weight of 1,000,000 g / mol, mix it with methyl methacrylate (MMA) at a weight ratio of 7.5:100, stir at 25°C until completely dissolved to obtain a resin solution, and measure the viscosity of the resin solution to be 480 mPa•s.

[0042] S2. Add multi-walled carbon nanotubes to the resin solution at a mass ratio of 1.0% as a conductive filler, and stir at high speed for 60 minutes to ensure uniform dispersion of the filler. The multi-walled carbon nanotubes used have undergone carboxylation surface treatment. Add methyl ethyl ketone peroxide (MEKP) as an initiator at a mass ratio of 1.0% of the resin solution. Stir evenly to form a mixed resin solution.

[0043] S3. Select short-cut flax fibers with a length of 2~5mm as reinforcing fiber materials, and combine the reinforcing fiber materials with the mixed resin liquid by casting molding: after mixing the resin liquid and reinforcing fiber materials, pour it into the mold, vibrate to remove air bubbles, and cure at 60℃ for 3 hours to obtain a PMMA composite material with integrated structure and function.

[0044] Tests have shown that multi-walled carbon nanotubes can be uniformly dispersed in resin solutions and in the final conductive PMMA composite material. This material is suitable for cutting-edge fields that require a combination of conductivity, electromagnetic properties, structural strength, and lightweight properties.

[0045] Example 5 A method for preparing a structurally and functionally integrated PMMA composite material includes the following steps: S1. Take an acrylate core-shell copolymer (ACR) with a weight average molecular weight of 500,000 g / mol, mix it with methyl methacrylate (MMA) at a weight ratio of 10:100, stir at 25°C until completely dissolved to obtain a resin solution, and measure the viscosity of the resin solution to be 210 mPa•s.

[0046] S2. Add fluorescent filler to the resin solution at a mass ratio of 3.0%, and stir at high speed for 60 minutes to ensure uniform dispersion of the filler. The fluorescent filler used has undergone PMMA suspension polymerization surface coating treatment. Add tert-butyl peroxide (TBPO) as an initiator at a mass ratio of 1.0% of the resin solution. Stir evenly to form a mixed resin solution.

[0047] S3. Two-dimensional woven glass fiber fabric is selected as the reinforcing fiber material. The reinforcing fiber material is combined with the mixed resin liquid by hand lay-up molding: first, the resin liquid is brushed onto the mold, then the glass fiber cloth is laid, air bubbles are removed with rollers, and the layers are stacked to the required thickness; the composite material is cured at 70°C for 5 hours to obtain a structural and functional PMMA composite material.

[0048] The fluorescent filler was tested and found to be uniformly dispersed in the resin solution and the final fluorescent PMMA composite material. This material is suitable for fields with special requirements for visualization, safety, aesthetics and light management.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a structurally and functionally integrated PMMA composite material, characterized in that, Includes the following steps: S1. Mix acrylate core-shell copolymers with a weight average molecular weight of 500,000 to 2,500,000 g / mol and methyl methacrylate in a mass ratio of (1 to 20): 100 to obtain a resin solution. S2. Add functional fillers and initiators, accounting for 0.1~10% by mass of the resin solution, to the above resin solution respectively, and mix to obtain a stable resin solution; S3. After the reinforcing fiber material is combined with the stabilized resin liquid, an in-situ bulk polymerization reaction is initiated to prepare the structure-functional integrated PMMA composite material.

2. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, In S1, the weight-average molecular weight of the acrylate core-shell copolymer is 500,000~2,500,000 g / mol.

3. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, In S1, the viscosity of the resin solution is 50~1000 mPa•s at 25℃.

4. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, In S2, the functional filler includes one or more of photochromic fillers, thermochromic fillers, electromagnetic wave shielding fillers, radiation shielding fillers, and conductive fillers; Alternatively, the functional filler may undergo surface treatment, and the surface treatment method may include coupling agent modification, polymer coating modification, or surfactant modification. Alternatively, the initiator may be a free radical initiator, including one or more of azo initiators, organic peroxide initiators, and redox system initiators.

5. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, The types of reinforcing fiber materials include one or more of glass fiber, carbon fiber, basalt fiber, and plant fiber.

6. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, In S3, the reinforcing fiber material is chopped fiber or continuous fiber cloth; Alternatively, the continuous fiber fabric may be one or more of a unidirectional continuous fiber fabric, a two-dimensional laminated structure fabric, or a three-dimensional woven structure fabric; the single layer of the two-dimensional laminated structure fabric may be one of a plain weave, a twill weave, or a satin weave; the three-dimensional woven structure fabric may be one of a three-dimensional four-directional, a three-dimensional five-directional, a three-dimensional six-directional, or a three-dimensional seven-directional fabric.

7. The method for preparing the structurally and functionally integrated PMMA composite material according to claim 1, characterized in that, In S3, the composite method includes one of the following: casting molding, vacuum injection molding, hand lay-up molding, filament winding molding, or pultrusion molding.

8. The method for preparing the structurally and functionally integrated PMMA composite material as described in claim 1, characterized in that, In S3, the initiation method for the in-situ bulk polymerization reaction includes thermal initiation.

9. A method for preparing a structurally and functionally integrated PMMA composite material as described in any one of claims 1-8.

10. An application of the structurally functional PMMA composite material as described in claim 9.