Liquid acrylic resin based on multi-layer core-shell structure as well as preparation method and application of liquid acrylic resin

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to liquid acrylic resin based on a multi-layer core-shell structure as well as a preparation method and application of the liquid acrylic resin. The preparation method comprises the following steps: equally dividing a multi-layer core-shell modifier into two parts, and adding the two parts 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 of butyl acrylate, butadiene or acrylic acid-2-phenoxyethyl ester; the shell layer of the multi-layer core-shell modifier is prepared from at least one shell layer monomer of methyl methacrylate, styrene, butyl acrylate, butadiene or acrylic acid-2-phenoxyethyl ester. The core-shell modifier disclosed by the invention can be dissolved in methacrylic resin to prepare a resin product with certain viscosity. The polymerized product has excellent toughness and impact resistance, and the brittleness problem of PMMA is solved while the good optical performance is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a liquid acrylic resin based on a multi-layer core-shell structure and a preparation method and application thereof. Background Art

[0002] Liquid acrylic resin is a new type of material that has received widespread attention in recent years. Compared with traditional solid resin or prepolymer systems, it has significant advantages: liquid acrylic resin can be processed at room temperature without solvent, has good fluidity and easy processing, and can still maintain high transparency, weather resistance and excellent mechanical properties after curing. These characteristics make liquid acrylic resin show great potential in the fields of environmentally friendly high-performance composite materials, optical materials, architectural coatings and 3D printing. In the existing market, representative products of commercial applications of liquid acrylic resin are extremely scarce. At present, liquid acrylic resins with good use effects are monopolized by foreign companies, such as Arkema's Elium resin. However, similar to other traditional resin systems, liquid acrylic resins show certain brittleness after curing, and their impact resistance needs to be further improved, especially in applications in the fields of high toughness and high reliability. This problem has become a key bottleneck restricting its development.

[0003] As a highly efficient toughness-modifying additive, core-shell modifiers can significantly improve the impact resistance of the base material through their unique core-shell structure. The core layer of the core-shell modifier is usually composed of a soft material with high elasticity (such as polybutadiene or polyacrylate rubber, etc.), which provides good stress absorption capacity; the shell layer is composed of a hard material with high strength (such as polymethyl methacrylate or polystyrene, etc.), which gives it good interface compatibility and dispersibility. After the core-shell modifier is added to the liquid acrylic resin, its core-shell structure can not only absorb and disperse the impact energy, but also improve the compatibility between the modifier and the matrix through interfacial bonding, thereby achieving a significant improvement in impact resistance.

[0004] However, there are still multiple technical challenges in the use of core-shell modifiers to modify liquid acrylic resins: the unique processing environment of liquid acrylic resin systems; the design parameters of modifiers, etc. Based on the above background, 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 core-shell modifiers in response to the unique performance requirements of liquid acrylic resins, provides technical support for the widespread application of liquid acrylic resins in high-performance composite materials and structural components, and also brings some solutions to the development of this emerging field of liquid acrylic resins. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for preparing a liquid acrylic resin based on a multilayer core-shell structure. By introducing a core-shell structure modifier, a thermoplastic liquid acrylic resin with good toughness and impact resistance is prepared.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A preparation method of a liquid acrylic resin based on a multi-layer core-shell structure comprises the following steps: dividing a multi-layer core-shell modifier into two parts and adding the parts into methyl methacrylate in batches to obtain a core-shell modifier / liquid acrylic resin; a core layer of the multi-layer core-shell modifier is made of at least one core layer monomer selected from butyl acrylate, butadiene or 2-phenoxyethyl acrylate; and a shell layer of the multi-layer core-shell modifier is made of at least one shell layer monomer selected from methyl methacrylate, styrene, butyl acrylate, butadiene or 2-phenoxyethyl acrylate.

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

[0009] Furthermore, the preparation method of the multilayer core-shell modifier is as follows: (1) polymerizing the core layer monomer under emulsion polymerization conditions to form a rubber core solution, (2) adding the shell layer monomer and the second initiator thereto, initiating a copolymerization reaction of the shell layer monomer on the surface of the rubber shell, or repeating the operation of step (2) to obtain the multilayer core-shell modifier.

[0010] Furthermore, the particle size of the multi-layer 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: adding an emulsifier into water, adding a core layer monomer and a first initiator after heating, and polymerizing to form a rubber core solution.

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

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

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

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

[0016] The second object of the present invention is to provide a liquid acrylic resin based on a multi-layer core-shell structure, which is prepared according to the above-mentioned preparation method.

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

[0018] To achieve the above object, the present invention adopts the following technical solutions:

[0019] The application of liquid acrylic resin based on multi-layer core-shell structure in preparing PMMA comprises the following steps: uniformly mixing the liquid acrylic resin prepared above with an initiator to obtain a mixture, and subjecting the mixture to polymerization reaction to obtain the mixture.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a liquid acrylic resin based on a multi-layer core-shell structure, and a preparation method and application thereof. The present invention uses any one of butadiene, butyl acrylate or 2-phenoxyethyl acrylate as a core or an intermediate layer, and uses at least one of methyl methacrylate (MMA), styrene, butyl acrylate, butadiene or 2-phenoxyethyl acrylate as a shell or an intermediate layer to prepare a core-shell modifier, and the prepared multi-layer core-shell modifier has a uniform particle size distribution. This type of core-shell modifier can be prepared into a liquid acrylic resin with MMA, and the liquid acrylic resin is a thermoplastic resin with good toughness and impact resistance. In addition, compared with traditional acrylic liquid acrylic resins, the present invention can effectively regulate the viscosity of the resin prepolymer and the impact resistance of the product by adjusting the type and amount of the core-shell modifier, so as to meet the requirements of different composite material processing techniques. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The particle size distribution diagram of the core-shell modifier obtained in Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further explained below in conjunction with specific embodiments, comparative examples, test examples and drawings.

[0024] In the following examples, comparative examples and test examples, the raw materials and preparation methods used are conventional materials and techniques in the art unless otherwise specified.

[0025] Example 1

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

[0027] (1) 1 g of sodium dodecyl sulfate was added to 157 mL of water, heated to 70° C. and stirred uniformly, 24 g of butyl acrylate was added thereto, and then 1.2 g of ammonium persulfate (APS) was added thereto, and the mixture was reacted for 15 min to form a rubber core solution;

[0028] (2) adding 16 g of methyl methacrylate and 0.8 g of ammonium persulfate to the rubber core solution; heating to 80° C., stirring at a speed of 300 r / min for 45 min, centrifuging and separating the core-shell particles after the reaction, washing with deionized water and drying to obtain a purified two-layer core-shell modifier;

[0029] (3) The two-layer core-shell modifier (accounting for 9% of the mass of MMA) obtained in step (2) was divided into two parts, and one of them was first added to MMA; then, it was stirred at a rate of 300 r / min for 1 hour, and then the remaining half of the two-layer core-shell modifier was added to the above mixture, and the stirring was continued at a rate of 300 r / min for 1 hour to obtain, which was recorded as core-shell modifier / liquid acrylic resin.

[0030] Example 2

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

[0032] (1) 2 g of sodium dodecyl sulfate was added to 275 g of water, heated to 60° C. and stirred evenly, 26 g of butyl acrylate and 1.8 g of ammonium persulfate (APS) were added thereto, and the mixture was reacted for 15 min and polymerized to form a rubber core solution;

[0033] (2) adding 16 g of butyl acrylate, 8 g of methyl methacrylate, and 1.2 g of ammonium persulfate to the rubber core solution; heating to 70° C., stirring at a speed of 300 r / min for 60 min, and after the reaction, adding 20 g of methyl methacrylate and 1 g of ammonium persulfate to carry out polymerization reaction again under the same conditions, and centrifuging, washing and drying after the polymerization reaction to obtain a purified three-layer core-shell modifier;

[0034] (3) The three-layer core-shell modifier obtained in step (2) (accounting for 10% of the mass of MMA) is divided into two parts, and one of them is first added to MMA; then, it is stirred at a rate of 300 r / min for 1 hour, and then, the remaining half of the three-layer core-shell modifier is added to the above mixture, and the stirring is continued at a rate of 300 r / min for 1 hour, and the mixture is obtained, which is recorded as core-shell modifier / liquid acrylic resin.

[0035] Example 3

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

[0037] (1) 2 g of sodium dodecyl sulfate was added to 275 mL of water, heated to 80° C. and stirred evenly, 13 g of butyl acrylate and 13 g of 2-phenoxyethyl acrylate were added thereto, and then 1.8 g of ammonium persulfate (APS) was added, and the mixture was reacted for 10 min and polymerized to form a rubber core solution;

[0038] (2) adding 8 g of butyl acrylate, 8 g of 2-phenoxyethyl acrylate, 8 g of methyl methacrylate and 1.2 g of ammonium persulfate to the rubber core solution; heating to 90° C., stirring at a speed of 300 r / min for 30 min, and after the reaction, adding 20 g of methyl methacrylate and 1 g of ammonium persulfate to carry out polymerization reaction again under the same conditions, and centrifuging, washing and drying after the polymerization reaction to obtain a purified three-layer core-shell modifier;

[0039] (3) The three-layer core-shell modifier obtained in step (2) (accounting for 10% of the mass of MMA) is divided into two parts, and one of them is first added to MMA; then, it is stirred at a rate of 300 r / min for 1 hour, and then, the remaining half of the three-layer core-shell modifier is added to the above mixture, and the stirring is continued at a rate of 300 r / min for 1 hour, and the mixture is obtained, which is recorded as core-shell modifier / liquid acrylic resin.

[0040] Example 4

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

[0042] (1) 1 g of sodium dodecyl sulfate was added to 157 mL of water, heated to 80° C. and stirred uniformly, 16 g of butyl acrylate and 8 g of 2-phenoxyethyl acrylate were added thereto, and then 1.2 g of ammonium persulfate (APS) was added, and the mixture was reacted for 10 min and polymerized to form a rubber core solution;

[0043] (2) adding 16 g of methyl methacrylate and 0.8 g of ammonium persulfate to the rubber core solution; heating to 80° C., stirring at a speed of 300 r / min for 45 min, centrifuging and separating the core-shell particles after the reaction, washing with deionized water, and then drying to obtain a purified two-layer core-shell modifier;

[0044] (3) The two-layer core-shell modifier (accounting for 11% of the mass of MMA) obtained in step (2) was divided into two parts, and one of them was first added to MMA; then, it was stirred at a rate of 300 r / min for 1 hour, and then the remaining half of the two-layer core-shell modifier was added to the above mixture, and the stirring was continued at a rate of 300 r / min for 1 hour to obtain, which was recorded as core-shell modifier / liquid acrylic resin.

[0045] Comparative Example 1

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

[0047] Comparative Example 2

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

[0049] Test Example 1

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

[0051] Figure 1 is the particle size distribution diagram of the core-shell modifier, where Figure 1 (a) to (d) correspond to the particle size distribution diagrams of the core-shell modifiers obtained in Examples 1 to 4. It can be seen from the figure that the particle sizes of the samples of Examples 1 to 4 prepared by this method are uniformly distributed in the range of 200-300 nm, which is a good idea 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] Test 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, and the mixture was added to a 120mm*70mm*8mm polytetrafluoroethylene mold, in which a 46.88mm*7.81mm*2mm dumbbell-shaped specimen was provided, and the polymerization reaction was carried out at 80°C for 6h, and the sample to be tested was obtained by cooling and demolding. The mechanical properties of the liquid acrylic resin material based on the multilayer core-shell structure obtained in Examples 1-4 and Comparative Examples 1-2 of the present invention were tested according to the test standard of ISO 527-2, and 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 can be seen from 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. The tensile strength and flexural strength of the liquid acrylic resin based on the multi-layer core-shell structure of Examples 2 and 3 are relatively high. The tensile strength and flexural strength of the liquid acrylic resin based on the multi-layer core-shell structure obtained in Example 3 are 73.90 MPa and 142.59 MPa, respectively. The tensile strength and flexural strength of the liquid acrylic resin based on the multi-layer core-shell structure obtained in Example 2 are 69.78 MPa and 135.66 MPa, respectively. It can be seen that the multi-layer core-shell modifier of the present invention can effectively improve the mechanical properties of the liquid acrylic resin.

[0057] In summary, the present invention provides a liquid acrylic resin based on a multi-layer core-shell structure modifier, and a preparation method and application thereof. The method is to mix the synthesized multi-layer core-shell modifier with MMA in a certain proportion, and the core-shell modifier will dissolve in the MMA to prepare a resin product with a certain viscosity. The liquid acrylic resin will have a wider range of applications, and the product after polymerization of the present invention has high impact resistance, and while ensuring good optical properties, it also solves the brittleness of the PMMA product itself.

[0058] The above are only preferred embodiments of the present invention, and are not limited to the above examples. For those skilled in the art, various changes and variations are possible under the principle of the present invention. Any modifications and improvements made should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a liquid acrylic resin based on a multi-layer core-shell structure, characterized in that: The steps include: The 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 made of at least one core layer monomer selected from butyl acrylate, butadiene or 2-phenoxyethyl acrylate; the shell layer of the multi-layer core-shell modifier is made of at least one shell layer monomer selected from methyl methacrylate, styrene, butyl acrylate, butadiene or 2-phenoxyethyl acrylate.

2. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 1, characterized in that: The multi-layer core-shell modifier accounts for 9-11 wt % of methyl methacrylate.

3. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 1 or 2, characterized in that: The preparation method of the multilayer core-shell modifier is as follows: (1) polymerizing the core layer monomer under emulsion polymerization conditions to form a rubber core solution, (2) adding the shell layer monomer and the second initiator thereto, initiating a copolymerization reaction of the shell layer monomer on the surface of the rubber shell, or repeating the operation of step (2) to obtain the multilayer core-shell modifier.

4. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 3, characterized in that: The specific preparation steps of the rubber core solution are as follows: adding an emulsifier into water, adding a core layer monomer and a first initiator after heating, and polymerizing to form a rubber core solution.

5. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 4, characterized in that: When preparing the rubber core solution, the mass ratio of the emulsifier, the core layer monomer, the first initiator and water is 1:13-24:0.9-1.2:137.5-157.

6. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 3, characterized in that: The mass ratio of the core layer monomer, the shell layer monomer and the second initiator is 11.8-30:20:

1.

7. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 3, characterized in that: The first initiator and the second initiator are any one of sodium persulfate, ammonium persulfate or potassium persulfate.

8. The method for preparing a liquid acrylic resin based on a multi-layer core-shell structure according to claim 3, characterized in that: The temperature of the emulsion polymerization in step (1) is 60-80°C and the time is 15-30 minutes; the temperature of the polymerization reaction in step (2) is 70-90°C and the time is 30-60 minutes.

9. A liquid acrylic resin based on a multi-layer core-shell structure, characterized in that: Prepared according to the preparation method according to claim 1.

10. Use of the liquid acrylic resin based on the multi-layer core-shell structure according to claim 9 in the preparation of PMMA, characterized in that: The method comprises the following steps: uniformly mixing the liquid acrylic resin prepared above with an initiator to obtain a mixture, and subjecting the mixture to a polymerization reaction to obtain the mixture.

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