Liquid acrylic resin based on multi-layer core-shell structure, and preparation method and application thereof

Abstract

The application belongs to the technical field of high polymer materials, and particularly relates to a liquid acrylic resin based on a multi-layer core-shell structure and a preparation method and application thereof. The preparation steps are as follows: a multi-layer core-shell modifier is divided into two parts and added into methyl methacrylate in batches to obtain a core-shell modifier / liquid acrylic resin; the core layer of the multi-layer core-shell modifier is prepared from at least one core layer monomer selected from butyl acrylate, butadiene or 2-phenoxyethyl acrylate; and the shell layer of the multi-layer core-shell modifier is prepared from at least one shell layer monomer selected from methyl methacrylate, styrene, butyl acrylate, butadiene or 2-phenoxyethyl acrylate. The core-shell modifier of the application can be dissolved in the methyl methacrylate to prepare a resin product with a certain viscosity. The polymerized product of the application has excellent toughness and impact resistance, and can ensure good optical performance while solving the brittleness problem of PMMA itself.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a liquid acrylic resin based on a multilayer core-shell structure, its preparation method, and its application. Background Technology

[0002] Liquid acrylic resins are a new type of material that has attracted widespread attention in recent years. Compared with traditional solid resins or prepolymer systems, they have significant advantages: liquid acrylic resins can be processed at room temperature without solvents, have good fluidity and easy processing, and maintain high transparency, weather resistance, and excellent mechanical properties after curing. These characteristics make liquid acrylic resins show great potential in environmentally friendly high-performance composite materials, optical materials, architectural coatings, and 3D printing. In the current market, commercially available representative products of liquid acrylic resins are extremely scarce. Currently, the liquid acrylic resins with good performance are monopolized by foreign companies, such as Arkema's Elium resin. However, similar to other traditional resin systems, liquid acrylic resins exhibit a certain degree of brittleness after curing, and their impact resistance needs further improvement, especially in applications requiring high toughness and high reliability. This issue has become a key bottleneck restricting their development.

[0003] Core-shell modifiers, as highly efficient toughness modifiers, significantly enhance the impact resistance of matrix materials through their unique core-shell structure. The core layer of a core-shell modifier is typically composed of a highly elastic soft material (such as polybutadiene or polyacrylate rubber), providing excellent stress absorption; the shell layer is composed of a high-strength hard material (such as polymethyl methacrylate or polystyrene), imparting good interfacial compatibility and dispersibility. When added to liquid acrylic resin, the core-shell structure not only absorbs and disperses impact energy but also improves the compatibility between the modifier and the matrix through interfacial bonding, thereby achieving a significant improvement in impact resistance.

[0004] However, several technical challenges remain in using core-shell modifiers to modify liquid acrylic resins: the unique processing environment of liquid acrylic resin systems and the design parameters of the modifiers. Against this backdrop, this technology provides a method for modifying liquid acrylic resins using core-shell modifiers, which can significantly improve their impact resistance after curing. This method optimizes the structure and preparation process of the core-shell modifier to address the unique performance requirements of liquid acrylic resins, providing technical support for the widespread application of liquid acrylic resins in high-performance composite materials and structural components, and also offering some solutions for the development of this emerging field. Summary of the Invention

[0005] One objective of this invention is to provide a method for preparing a liquid acrylic resin based on a multi-layered core-shell structure. By introducing a core-shell structure modifier, a thermoplastic liquid acrylic resin with good toughness and impact resistance is obtained.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing a liquid acrylic resin based on a multilayer core-shell structure includes the following steps: dividing a multilayer core-shell modifier into two equal parts and adding them to methyl methacrylate in several batches to obtain a core-shell modifier / liquid acrylic resin; wherein the core layer of the multilayer core-shell modifier is prepared by refining at least one core layer monomer selected from butyl acrylate, butadiene, or 2-phenoxyethyl acrylate; and the shell layer of the multilayer core-shell modifier is prepared by refining at least one shell layer monomer selected from methyl methacrylate, styrene, butyl acrylate, butadiene, or 2-phenoxyethyl acrylate.

[0008] Furthermore, the multilayer core-shell modifier accounts for 9-11 wt% of methyl methacrylate.

[0009] Further, the preparation method of the multilayer core-shell modifier is as follows: (1) polymerize the core layer monomer under emulsion polymerization conditions to form a rubber core solution, (2) add the shell layer monomer and the second initiator to it, and initiate the copolymerization reaction of the shell layer monomer on the surface of the rubber shell to obtain the core solution, or repeat the operation of step (2) to obtain the core solution.

[0010] Furthermore, the particle size of the multilayer core-shell modifier is uniformly distributed in the range of 200-300 nm.

[0011] Furthermore, the specific preparation steps of the rubber core solution are as follows: add emulsifier to water, heat, then add core layer monomer and first initiator, and polymerize to form rubber core solution.

[0012] Furthermore, in preparing the rubber core solution, the mass ratio of the emulsifier, core layer monomer, first initiator, and water is 1:13-24:0.9-1.2:137.5-157.

[0013] Furthermore, the mass ratio of the core monomer, the shell monomer, and the second initiator is 11.8-30:20:1.

[0014] Furthermore, both the first initiator and the second initiator are any one of sodium persulfate, ammonium persulfate, or potassium persulfate.

[0015] Further, the temperature of the emulsion polymerization in step (1) is 60-80℃ and the time is 5-30 min; the temperature of the polymerization reaction in step (2) is 70-90℃ and the time is 30-60 min.

[0016] The second objective of this invention is to provide a liquid acrylic resin based on a multilayer core-shell structure, prepared according to the above-described preparation method.

[0017] The third objective of this invention is to provide the application of liquid acrylic resin based on a multi-layer core-shell structure in the preparation of PMMA. Compared with traditional acrylic resins, this invention can effectively control the viscosity of the resin prepolymer and the impact resistance of the product by adjusting the type and amount of core-shell modifier, thus meeting the requirements of different composite material processing technologies.

[0018] To achieve the above objectives, the present invention adopts the following technical solution:

[0019] The application of liquid acrylic resin with a multi-layer core-shell structure in the preparation of PMMA includes the following steps: mixing the liquid acrylic resin obtained above with an initiator to obtain a mixture, and then carrying out a polymerization reaction on the mixture.

[0020] Compared with the prior art, the beneficial effects of this invention are as follows:

[0021] This invention provides a liquid acrylic resin based on a multi-layer core-shell structure, its preparation method, and its applications. The invention uses any one of butadiene, butyl acrylate, or 2-phenoxyethyl acrylate as the core or intermediate layer, and at least one of methyl methacrylate (MMA), styrene, butyl acrylate, butadiene, or 2-phenoxyethyl acrylate as the shell or intermediate layer to prepare a core-shell modifier. The resulting multi-layer core-shell modifier has a uniform particle size distribution. This type of core-shell modifier can be combined with MMA to prepare a liquid acrylic resin, which is a thermoplastic resin with good toughness and impact resistance. Furthermore, compared with traditional liquid acrylic resins, this invention can effectively control the viscosity of the resin prepolymer and the impact resistance of the finished product by adjusting the type and amount of the core-shell modifier, meeting the requirements of different composite material processing techniques. Attached Figure Description

[0022] Figure 1 This is a particle size distribution diagram of the core-shell modifiers obtained in Examples 1-4 of the present invention. Detailed Implementation

[0023] The technical solution of the present invention will be further explained below with reference to specific embodiments, comparative examples, experimental examples and accompanying drawings.

[0024] Unless otherwise specified, the raw materials and preparation methods used in the following examples, comparative examples, and experimental cases are all conventional materials and techniques in the art.

[0025] Example 1

[0026] A method for preparing a liquid acrylic resin based on a multilayer core-shell structure includes the following steps:

[0027] (1) Add 1g sodium dodecyl sulfate to 157mL water, heat to 70℃ and stir evenly, add 24g butyl acrylate, then add 1.2g ammonium persulfate (APS), and polymerize to form a rubber core solution after reacting for 15min.

[0028] (2) Add 16g of methyl methacrylate and 0.8g of ammonium persulfate to the rubber core solution; heat to 80℃ and stir at 300r / min for 45min. After the reaction is completed, centrifuge to separate the core and shell particles, wash with deionized water and dry to obtain the purified two-layer core and shell modifier.

[0029] (3) Divide the two-layer core-shell modifier (accounting for 9% of the mass of MMA) obtained in step (2) into two equal parts, and first add one part to the MMA; then stir at a rate of 300 r / min for 1 h, and then add the remaining half of the two-layer core-shell modifier to the above mixture, and continue stirring at a rate of 300 r / min for 1 h, which is the result, denoted as core-shell modifier / liquid acrylic resin.

[0030] Example 2

[0031] A method for preparing a liquid acrylic resin based on a multilayer core-shell structure includes the following steps:

[0032] (1) Add 2g sodium dodecyl sulfate to 275g water, heat to 60℃ and stir evenly, add 26g butyl acrylate and 1.8g ammonium persulfate (APS), react for 15min and polymerize to form a rubber core solution;

[0033] (2) Add 16g butyl acrylate, 8g methyl methacrylate and 1.2g ammonium persulfate to the rubber core solution; heat to 70℃ and stir at 300r / min for 60min. After the reaction is completed, add 20g methyl methacrylate and 1g ammonium persulfate under the same conditions to carry out the polymerization reaction again. After the polymerization reaction is completed, centrifuge, wash and dry to obtain the purified three-layer core-shell modifier.

[0034] (3) Divide the three-layer core-shell modifier (accounting for 10% of the mass of MMA) obtained in step (2) into two equal parts, and add one part to the MMA first; then stir at a rate of 300 r / min for 1 h, and then add the remaining half of the three-layer core-shell modifier to the above mixture, and continue stirring at a rate of 300 r / min for 1 h, which is the result, denoted as core-shell modifier / liquid acrylic resin.

[0035] Example 3

[0036] A method for preparing a liquid acrylic resin based on a multilayer core-shell structure includes the following steps:

[0037] (1) Add 2g sodium dodecyl sulfate to 275mL of water, heat to 80℃ and stir evenly. Add 13g butyl acrylate and 13g 2-phenoxyethyl acrylate to the mixture, and then add 1.8g ammonium persulfate (APS). After reacting for 10min, polymerize to form a rubber core solution.

[0038] (2) Add 8g butyl acrylate, 8g 2-phenoxyethyl acrylate, 8g methyl methacrylate and 1.2g ammonium persulfate to the rubber core solution; heat to 90℃ and stir at 300r / min for 30min. After the reaction is completed, add 20g methyl methacrylate and 1g ammonium persulfate under the same conditions to carry out the polymerization reaction again. After the polymerization reaction is completed, centrifuge, wash and dry to obtain the purified three-layer core-shell modifier.

[0039] (3) Divide the three-layer core-shell modifier (accounting for 10% of the mass of MMA) obtained in step (2) into two equal parts, and add one part to the MMA first; then stir at a rate of 300 r / min for 1 h, and then add the remaining half of the three-layer core-shell modifier to the above mixture, and continue stirring at a rate of 300 r / min for 1 h, which is the result, denoted as core-shell modifier / liquid acrylic resin.

[0040] Example 4

[0041] A method for preparing a multi-layered core-shell liquid acrylic resin includes the following steps:

[0042] (1) Add 1g sodium dodecyl sulfate to 157mL water, heat to 80℃ and stir evenly, add 16g butyl acrylate and 8g 2-phenoxyethyl acrylate, then add 1.2g ammonium persulfate (APS), and polymerize to form a rubber core solution after reacting for 10min.

[0043] (2) Add 16g of methyl methacrylate and 0.8g of ammonium persulfate to the rubber core solution; heat to 80℃ and stir at 300r / min for 45min. After the reaction is completed, centrifuge to separate the core and shell particles, wash with deionized water, and then dry to obtain the purified two-layer core and shell modifier.

[0044] (3) Divide the two-layer core-shell modifier (accounting for 11% of the mass of MMA) obtained in step (2) into two equal parts, and first add one part to the MMA; then stir at a rate of 300 r / min for 1 h, and then add the remaining half of the two-layer core-shell modifier to the above mixture, and continue stirring at a rate of 300 r / min for 1 h, which is the result, denoted as core-shell modifier / liquid acrylic resin.

[0045] Comparative Example 1

[0046] Comparative Example 1 and Example 4 are basically the same, except that: when preparing the modifier, 1g of sodium dodecyl sulfate was added to 157mL of water, heated to 80°C and stirred evenly, 16g of butyl acrylate, 8g of 2-phenoxyethyl acrylate, 16g of methyl methacrylate and 2.0g of ammonium persulfate (APS) were added, heated to 80°C and stirred at 300r / min for 45min. After the reaction was completed, the mixture was centrifuged and washed with deionized water to obtain the modifier.

[0047] Comparative Example 2

[0048] Comparative Example 2 and Example 3 are basically the same, except that: when preparing acrylic resin, step (3) is: the three-layer core-shell modifier (accounting for 10% of the mass of MMA) obtained in step (2) is directly added to MMA and stirred for 2 hours to obtain the product.

[0049] Experimental Example 1

[0050] The particle size of the core-shell modifiers obtained in Examples 1-4 of this invention was tested, and the experimental results are as follows: Figure 1 As shown.

[0051] Figure 1 This is a particle size distribution diagram of the core-shell modifier, where... Figure 1 Figures (a) to (d) correspond to the particle size distribution diagrams of the core-shell modifiers obtained in Examples 1-4, respectively. As can be seen from the figures, the particle sizes of the samples obtained by this method in Examples 1-4 are uniformly distributed between 200-300 nm. This provides a good approach for controlling the particle size of the core-shell modifier and helps to further improve the performance of the core-shell modifier / liquid acrylic resin material.

[0052] Experimental Example 2

[0053] The core-shell modifier / liquid acrylic resin prepared in Examples 1-4 and Comparative Examples 1-2 was mixed with benzoyl peroxide at a mass ratio of 198:2. The mixture was then added to a 120mm*70mm*8mm polytetrafluoroethylene mold containing a dumbbell-shaped sample measuring 46.88mm*7.81mm*2mm. The polymerization reaction was carried out at 80℃ for 6 hours. After cooling and demolding, the sample was obtained for testing. The mechanical properties of the liquid acrylic resin materials based on the multilayer core-shell structure obtained in Examples 1-4 and Comparative Examples 1-2 were tested according to ISO 527-2. The experimental results are shown in Table 1.

[0054] Table 1

[0055] Group Tensile strength (MPa) Tensile modulus (MPa) Bending strength (MPa) Flexural modulus (MPa) Example 1 54.07 3555.56 84.56 3128.13 Example 2 69.78 4017.78 135.66 3992.78 Example 3 73.90 4235.18 142.59 4262.38 Example 4 65.89 3968.26 130.63 3759.26 Comparative Example 1 39.27 2586.32 75.29 2853.94 Comparative Example 2 63.54 3786.28 103.36 3568.29

[0056] As shown in Table 1, the tensile strength of Examples 1-4 of the present invention is maintained above 54 MPa, and the flexural strength is maintained above 84.56 MPa. Among them, the liquid acrylic resin based on the multilayer core-shell structure in Examples 2 and 3 has higher tensile and flexural strengths. The tensile and flexural strengths of the liquid acrylic resin based on the multilayer core-shell structure obtained in Example 3 are 73.90 MPa and 142.59 MPa, respectively, and the tensile and flexural strengths of the liquid acrylic resin based on the multilayer core-shell structure obtained in Example 2 are 69.78 MPa and 135.66 MPa, respectively. It can be seen that the multilayer core-shell modifier of the present invention can effectively improve the mechanical properties of liquid acrylic resin.

[0057] In summary, this invention provides a liquid acrylic resin based on a multilayer core-shell structure modifier, its preparation method, and its applications. This method involves mixing the synthesized multilayer core-shell modifier with MMA in a specific ratio. The core-shell modifier dissolves in the MMA, resulting in a resin product with a certain viscosity. This liquid acrylic resin has a wider range of applications. The polymerized product of this invention exhibits high impact resistance and addresses the brittleness of PMMA products while maintaining excellent optical properties.

[0058] The above are merely preferred embodiments of the present invention and are not limited to the examples described above. Those skilled in the art will recognize that various modifications and variations can be made based on the principles of the present invention. Any modifications or improvements made should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing liquid acrylic resin based on a multilayer core-shell structure, characterized in that, Includes the following steps: The multilayer core-shell modifier was divided into two equal parts and added to methyl methacrylate in several batches to obtain a core-shell modifier / liquid acrylic resin; the core layer of the multilayer core-shell modifier was prepared by selecting at least one core layer monomer selected from butyl acrylate, butadiene, or 2-phenoxyethyl acrylate; the shell layer of the multilayer core-shell modifier was prepared by selecting at least one shell layer monomer selected from methyl methacrylate, styrene, butyl acrylate, butadiene, or 2-phenoxyethyl acrylate. The specific steps for adding the multilayer core-shell modifier to methyl methacrylate in two parts are as follows: First, add one part to methyl methacrylate and stir at a rate of 300 r / min for 1 hour. Then, add the remaining half of the multilayer core-shell modifier to the above mixture and continue stirring at a rate of 300 r / min for 1 hour. The multilayer core-shell modifier accounts for 9-11 wt% of methyl methacrylate; The preparation method of the multilayer core-shell modifier is as follows: (1) polymerize the core layer monomer under emulsion polymerization conditions to form a rubber core solution; (2) add the shell layer monomer and the second initiator to it, and initiate the copolymerization reaction of the shell layer monomer on the surface of the rubber shell to obtain the solution; or repeat the operation of step (2) to obtain the solution. The mass ratio of the core monomer, the shell monomer, and the second initiator is (11.8-30):20:

1.

2. The method for preparing liquid acrylic resin based on a multi-layered core-shell structure according to claim 1, characterized in that, The specific preparation steps of the rubber core solution are as follows: add emulsifier to water, heat, add core layer monomer and first initiator, and polymerize to form rubber core solution.

3. The method for preparing liquid acrylic resin based on a multi-layered core-shell structure according to claim 2, characterized in that, When preparing the rubber core solution, the mass ratio of the emulsifier, core layer monomer, first initiator and water is 1:(13-24):(0.9-1.2):(137.5-157); the first initiator is any one of sodium persulfate, ammonium persulfate or potassium persulfate.

4. The method for preparing liquid acrylic resin based on a multi-layered core-shell structure according to claim 1, characterized in that, The second initiator is any one of sodium persulfate, ammonium persulfate, or potassium persulfate.

5. The method for preparing liquid acrylic resin based on a multi-layered core-shell structure according to claim 1, characterized in that, The emulsion polymerization in step (1) is carried out at a temperature of 60-80℃ for 15-30 min; the copolymerization reaction in step (2) is carried out at a temperature of 70-90℃ for 30-60 min.

6. A liquid acrylic resin based on a multi-layered core-shell structure, characterized in that, Prepared by the preparation method according to any one of claims 1-5.

7. The application of the liquid acrylic resin based on a multi-layered core-shell structure as described in claim 6 in the preparation of PMMA, characterized in that, The process includes the following steps: mixing the liquid acrylic resin obtained above with an initiator to obtain a mixture, and then subjecting the mixture to a polymerization reaction.

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