A method for preparing core-shell structure ACR resin

Abstract

The present invention discloses a method for preparing a core-shell structure ACR resin, which belongs to the field of polymer compounds. The preparation method comprises preparing an ACR seed emulsion, preparing a core emulsion, preparing an emulsion containing a mantle layer, and preparing an ACR resin. The ACR resin prepared by the invention can effectively improve the resistance to wet heat aging of polycarbonate. The ACR resin of the present invention is blended with polycarbonate to prepare a sample, and a wet heat aging test is performed. The tensile strength after 504h wet heat aging is 67.9-68.8MPa, the tensile strength after 1008h wet heat aging is 53.2-53.6MPa, and the tensile strength after 1512h wet heat aging is 38.2-39.2MPa.

Description

Technical Field

[0001] The invention relates to a method for preparing a core-shell structured ACR resin, and belongs to the field of polymer compounds. Background Art

[0002] PC (polycarbonate) is a type of engineering plastic with excellent performance in all aspects. It has great advantages in heat resistance, molding dimensional stability and flame retardancy, so it is widely used in electronic appliances, automobiles, sports equipment and other fields. However, PC molecular chains contain a large number of benzene rings, which makes it difficult for the molecular chains to move, resulting in a high viscosity of PC melt. During the processing, PC molecular chains are oriented. After processing, some of the molecular chains that are not completely deoriented in the product tend to return to their natural state, which will cause a large amount of residual stress in the PC injection molded products, resulting in rupture during product use or storage. At the same time, PC is a notch-sensitive material. These shortcomings limit the further expansion of PC applications.

[0003] In view of the shortcomings of PC being notch-sensitive and prone to stress cracking, there are literature reports on the method of adding a small amount of acrylic copolymer (ACR) to improve the notch impact strength of PC. ACR is a core-shell structure particle. According to the silver-crawling-shear band toughening theory, the elastomer ACR plays a stress concentration role in PC products. When the material is subjected to impact force, the stress in the area around the equator of the elastomer particles is amplified. As the distance from the particles increases, the amplified stress quickly decreases to the original stress level. In addition, the stress concentration on the elastomer particles produces a large number of silver streaks, which in turn form shear bands, so that the impact force is absorbed and the molecular chains of the matrix resin are prevented from being destroyed. Another function of the elastomer ACR is to prevent the growth of silver streaks through its own deformation and cavitation, and prevent the silver streaks from further expanding into cracks, which will destroy the matrix material, thereby playing an impact toughening role.

[0004] Studies have shown that by introducing glycidyl methacrylate (GMA) monomer into the shell structure of the ACR core-shell structure, the interfacial adhesion between ACR and PC can be increased after the blending, thereby increasing the overall creep resistance of the material. However, as the adhesion between the elastomer and the interface increases, it is more likely to form cavities in the internal rubber part rather than the interface part during fracture. Therefore, the cavitation process in the PC / ACR system is hindered, which weakens the energy dissipation and inhibits the transition from cavitation to shear yield. This is not conducive to inducing the generation of shear yield and thus toughening. At the same time, the wet heat aging performance of the material will decrease, which is manifested as a decrease in tensile strength and elongation at break under wet heat conditions. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art. Chitosan is modified with vinyl and used as a component of the ACR resin shell layer. The structure of the ACR resin is designed as a three-layer structure of core layer-mantle layer-shell layer. While ensuring the toughening performance of the material, the material's resistance to aging in wet and hot conditions is improved.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for preparing a core-shell structured ACR resin comprises preparing an ACR seed emulsion, preparing a core emulsion, preparing an emulsion containing a mantle layer, and preparing an ACR resin.

[0008] The following are further improvements to the above technical solution:

[0009] The method for preparing the ACR seed emulsion is to mix butyl acrylate, methyl methacrylate, deionized water, an emulsifier, and a crosslinking agent uniformly, then heat the mixture to 70-75° C., add an initiator, mix the mixture uniformly, keep the temperature constant, and stir for 25-35 minutes, and obtain the ACR seed emulsion after stirring and emulsification;

[0010] The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 23-27:14-16:75-85:0.9-1.1:0.9-1.1:0.45-0.55;

[0011] The emulsifier is sodium lauryl sulfate;

[0012] The cross-linking agent is divinylbenzene;

[0013] The initiator is potassium persulfate.

[0014] The method for preparing the core emulsion is as follows: deionized water, an emulsifier, and an initiator are mixed and stirred evenly, and then butyl acrylate, methyl methacrylate, and a crosslinking agent are added thereto, and the temperature is controlled to be 72-78° C., and the stirring is performed for 20-30 minutes, and a core monomer pre-emulsion is obtained after stirring, and then the core monomer pre-emulsion is gradually added dropwise to the ACR seed emulsion, and the amount added per minute is controlled to be 8-12wt% of the total amount of the core monomer pre-emulsion, and after the addition is completed, the core monomer pre-emulsion is stirred at 78-82° C. for 55-65 minutes to obtain the core emulsion;

[0015] The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate and crosslinking agent is 70-80:0.9-1.1:0.25-0.35:18-22:18-22:0.9-1.1;

[0016] The emulsifier is sodium lauryl sulfate;

[0017] The cross-linking agent is divinylbenzene;

[0018] The initiator is potassium persulfate;

[0019] The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:0.9-1.1.

[0020] The method for preparing the emulsion containing the mantle layer comprises: uniformly mixing butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent to obtain a mantle layer emulsion; controlling the temperature to be 72-78° C.; slowly adding the core emulsion to the mantle layer emulsion; controlling the amount added per minute to be 8-12 wt % of the total amount of the core emulsion; and continuing stirring for 100-130 min after the addition is completed to obtain the emulsion containing the mantle layer;

[0021] The mass ratio of butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 14-16:9-11:23-27:80-90:0.9-1.1:0.55-0.65:0.9-1.1;

[0022] The emulsifier is sodium lauryl sulfate;

[0023] The cross-linking agent is divinylbenzene;

[0024] The initiator is potassium persulfate;

[0025] The mass ratio of the core emulsion to the mantle emulsion is 1:1.75-1.85.

[0026] The method for preparing the ACR resin comprises: uniformly mixing glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent to obtain a shell emulsion; controlling the temperature to be 77-82° C.; slowly adding the shell emulsion to an emulsion containing a mantle layer; controlling the amount added per minute to be 8-12 wt % of the total amount of the shell emulsion; and continuing stirring for 100-130 min after the addition is completed to obtain a final emulsion; spray drying the final emulsion to obtain the ACR resin;

[0027] The mass ratio of the glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 9-11:23-27:14-16:75-85:0.9-1.1:0.45-0.55:0.9-1.1;

[0028] The emulsifier is sodium lauryl sulfate;

[0029] The cross-linking agent is divinylbenzene;

[0030] The initiator is potassium persulfate;

[0031] The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:2.75-3.25;

[0032] The preparation method of the vinyl modified chitosan is:

[0033] Mixing chitosan with N,N-dimethylformamide, stirring to dissolve, obtaining a chitosan solution, adding 4-pyrrolidinopyridine as a catalyst to the chitosan solution, then adding allyl hydroxyethyl ether, controlling the temperature to 65-75° C., stirring to react, and reacting for 32-40 hours. After the reaction is completed, using anhydrous ethanol to precipitate the chitosan, filtering, washing, and drying to obtain vinyl-modified chitosan;

[0034] The mass ratio of chitosan to N,N-dimethylformamide is 1:20-30;

[0035] The amount of 4-pyrrolidinopyridine is 0.45-0.55wt% of the chitosan mass;

[0036] The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:3.75-4.25.

[0037] Compared with the prior art, the present invention achieves the following beneficial effects:

[0038] The ACR resin prepared by the present invention can effectively improve the bending properties of polycarbonate. The ACR resin of the present invention is blended with polycarbonate to prepare a sample. According to the method in GB / T9341-2008, the bending strength and bending modulus of the sample are tested. The bending strength is 103.7-105.1 MPa, and the bending modulus is 2734-2766 MPa.

[0039] The ACR resin prepared by the present invention can effectively improve the impact resistance of polycarbonate. The ACR resin of the present invention is blended with polycarbonate to prepare a sample. According to the method in GB / T1043.1-2008, the impact strength of the sample is tested, and the impact strength is 55.2-56.7 KJ / m 2 ;

[0040] The ACR resin prepared by the present invention can effectively improve the tensile properties of polycarbonate. The ACR resin of the present invention is blended with polycarbonate to prepare a sample. According to the method in GB / T1040.1-2018, the tensile strength and tensile modulus of the sample are tested. The tensile strength is 69.5-71.1 MPa, and the tensile modulus is 2378-2471 MPa.

[0041] The ACR resin prepared by the present invention can effectively improve the resistance of polycarbonate to wet heat aging. The ACR resin of the present invention is blended with polycarbonate to prepare a sample, and a wet heat aging test is performed. The tensile strength after 504h wet heat aging is 67.9-68.8MPa, the tensile strength after 1008h wet heat aging is 53.2-53.6MPa, and the tensile strength after 1512h wet heat aging is 38.2-39.2MPa; the elongation at break after 504h wet heat aging is 152-157%, the elongation at break after 1008h wet heat aging is 122-129%, and the elongation at break after 1512h wet heat aging is 87-91%; the impact strength after 504h wet heat aging is 48.8-49.5KJ / m 2 The impact strength after 1008h of wet heat aging is 41.3-42.2KJ / m 2 The impact strength after 1512h of wet heat aging is 34.9-35.6KJ / m 2 ;

[0042] The ACR resin prepared by the present invention can effectively improve the water boiling aging resistance of polycarbonate. The ACR resin of the present invention is blended with polycarbonate to prepare a sample, and a water boiling aging test is performed. The elongation at break after 21 days of water boiling aging is 158-164%, the elongation at break after 35 days of water boiling aging is 140-151%, and the elongation at break after 60 days of water boiling aging is 122-125%; the impact strength after 21 days of water boiling aging is 52.3-53.1 KJ / m 2 The impact strength after 35d water boiling aging is 50.7-51.4KJ / m 2 The impact strength after 60d water boiling aging is 48.6-49.1KJ / m 2 . DETAILED DESCRIPTION Example 1

[0043] (1) Preparation of ACR seed emulsion

[0044] Butyl acrylate, methyl methacrylate, deionized water, emulsifier and crosslinking agent were mixed evenly, then heated to 72°C, initiator was added and mixed evenly, the temperature was kept constant and stirred for 30 minutes, and ACR seed emulsion was obtained after stirring and emulsification;

[0045] The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 25:15:80:1:1:0.5;

[0046] The emulsifier is sodium lauryl sulfate;

[0047] The cross-linking agent is divinylbenzene;

[0048] The initiator is potassium persulfate.

[0049] (2) Preparation of nuclear emulsion

[0050] Deionized water, an emulsifier, and an initiator are mixed and stirred evenly, and then butyl acrylate, methyl methacrylate, and a crosslinking agent are added thereto, and the temperature is controlled to be 75° C. and stirred for 25 minutes to obtain a core monomer pre-emulsion. The core monomer pre-emulsion is then gradually added dropwise to the ACR seed emulsion, and the amount added per minute is controlled to be 10wt% of the total amount of the core monomer pre-emulsion. After the addition is completed, the mixture is stirred at 80° C. for 60 minutes to obtain a core emulsion.

[0051] The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate and crosslinking agent is 75:1:0.3:20:20:1;

[0052] The emulsifier is sodium lauryl sulfate;

[0053] The cross-linking agent is divinylbenzene;

[0054] The initiator is potassium persulfate;

[0055] The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:1.

[0056] (3) Preparation of emulsion containing mantle layer

[0057] Butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a mantle layer emulsion, and the temperature is controlled to be 75° C. The core emulsion is slowly added to the mantle layer emulsion, and the amount added per minute is controlled to be 10wt% of the total amount of the core emulsion. After the addition is completed, stirring is continued for 120 minutes to obtain an emulsion containing a mantle layer;

[0058] The mass ratio of butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 15:10:25:85:1:0.6:1;

[0059] The emulsifier is sodium lauryl sulfate;

[0060] The cross-linking agent is divinylbenzene;

[0061] The initiator is potassium persulfate;

[0062] The mass ratio of the core emulsion to the mantle emulsion is 1:1.8.

[0063] (4) Preparation of ACR resin

[0064] Glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a shell emulsion, the temperature is controlled to be 80° C., the shell emulsion is slowly added to the emulsion containing the mantle layer, and the amount added per minute is controlled to be 10wt% of the total amount of the shell emulsion. After the addition is completed, stirring is continued for 120 minutes to obtain a final emulsion, and the final emulsion is spray-dried to obtain an ACR resin;

[0065] The mass ratio of the glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and cross-linking agent is 10:25:15:80:1:0.5:1;

[0066] The emulsifier is sodium lauryl sulfate;

[0067] The cross-linking agent is divinylbenzene;

[0068] The initiator is potassium persulfate;

[0069] The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:3;

[0070] The preparation method of the vinyl modified chitosan is:

[0071] Chitosan and N,N-dimethylformamide are mixed and stirred to dissolve to obtain a chitosan solution, 4-pyrrolidinopyridine is added to the chitosan solution as a catalyst, and then allyl hydroxyethyl ether is added, the temperature is controlled to 70°C, and the reaction is stirred for 36 hours. After the reaction is completed, the chitosan is precipitated with anhydrous ethanol, and then filtered, washed, and dried to obtain vinyl-modified chitosan;

[0072] The mass ratio of chitosan to N,N-dimethylformamide is 1:25;

[0073] The amount of 4-pyrrolidinopyridine is 0.5wt% of the mass of chitosan;

[0074] The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:4.

[0075] Example 2

[0076] (1) Preparation of ACR seed emulsion

[0077] Butyl acrylate, methyl methacrylate, deionized water, emulsifier and crosslinking agent were mixed evenly, then heated to 70°C, initiator was added and mixed evenly, the temperature was kept constant and stirred for 35 minutes, and ACR seed emulsion was obtained after stirring and emulsification;

[0078] The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 23:14:75:0.9:0.9:0.45;

[0079] The emulsifier is sodium lauryl sulfate;

[0080] The cross-linking agent is divinylbenzene;

[0081] The initiator is potassium persulfate.

[0082] (2) Preparation of nuclear emulsion

[0083] Deionized water, an emulsifier, and an initiator are mixed and stirred evenly, and then butyl acrylate, methyl methacrylate, and a crosslinking agent are added thereto, and the temperature is controlled to be 72° C. and stirred for 30 minutes to obtain a core monomer pre-emulsion. The core monomer pre-emulsion is then gradually added dropwise to the ACR seed emulsion, and the amount added per minute is controlled to be 8wt% of the total amount of the core monomer pre-emulsion. After the addition is completed, the mixture is stirred at 82° C. for 55 minutes to obtain a core emulsion.

[0084] The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate and crosslinking agent is 70:0.9:0.25:18:18:0.9;

[0085] The emulsifier is sodium lauryl sulfate;

[0086] The cross-linking agent is divinylbenzene;

[0087] The initiator is potassium persulfate;

[0088] The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:0.9.

[0089] (3) Preparation of emulsion containing mantle layer

[0090] Butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a mantle layer emulsion, and the temperature is controlled to be 72° C. The core emulsion is slowly added to the mantle layer emulsion, and the amount added per minute is controlled to be 8wt% of the total amount of the core emulsion. After the addition is completed, stirring is continued for 130 minutes to obtain an emulsion containing a mantle layer;

[0091] The mass ratio of butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 14:9:23:80:0.9:0.55:0.9;

[0092] The emulsifier is sodium lauryl sulfate;

[0093] The cross-linking agent is divinylbenzene;

[0094] The initiator is potassium persulfate;

[0095] The mass ratio of the core emulsion to the mantle emulsion is 1:1.75.

[0096] (4) Preparation of ACR resin

[0097] Glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a shell emulsion, the temperature is controlled to be 77° C., the shell emulsion is slowly added to the emulsion containing the mantle layer, and the amount added per minute is controlled to be 8wt% of the total amount of the shell emulsion. After the addition is completed, stirring is continued for 130 minutes to obtain a final emulsion, and the final emulsion is spray-dried to obtain an ACR resin;

[0098] The mass ratio of glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and cross-linking agent is 9:23:14:75:0.9:0.45:0.9;

[0099] The emulsifier is sodium lauryl sulfate;

[0100] The cross-linking agent is divinylbenzene;

[0101] The initiator is potassium persulfate;

[0102] The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:2.75;

[0103] The preparation method of the vinyl modified chitosan is:

[0104] Chitosan and N,N-dimethylformamide are mixed and stirred to dissolve to obtain a chitosan solution, 4-pyrrolidinopyridine is added to the chitosan solution as a catalyst, and then allyl hydroxyethyl ether is added, the temperature is controlled to 65° C., and the reaction is stirred for 32 hours. After the reaction is completed, the chitosan is precipitated with anhydrous ethanol, and then filtered, washed, and dried to obtain vinyl-modified chitosan;

[0105] The mass ratio of chitosan to N,N-dimethylformamide is 1:20;

[0106] The amount of 4-pyrrolidinopyridine is 0.45wt% of the mass of chitosan;

[0107] The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:3.75.

[0108] Example 3

[0109] (1) Preparation of ACR seed emulsion

[0110] Butyl acrylate, methyl methacrylate, deionized water, emulsifier and crosslinking agent were mixed evenly, then heated to 75°C, initiator was added and mixed evenly, the temperature was kept constant and stirred for 25 minutes, and ACR seed emulsion was obtained after stirring and emulsification;

[0111] The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 27:16:85:1.1:1.1:0.55;

[0112] The emulsifier is sodium lauryl sulfate;

[0113] The cross-linking agent is divinylbenzene;

[0114] The initiator is potassium persulfate.

[0115] (2) Preparation of nuclear emulsion

[0116] Deionized water, an emulsifier, and an initiator are mixed and stirred evenly, and then butyl acrylate, methyl methacrylate, and a crosslinking agent are added thereto, and the temperature is controlled to be 78° C. and stirred for 20 minutes to obtain a core monomer pre-emulsion. The core monomer pre-emulsion is then gradually added dropwise to the ACR seed emulsion, and the amount added per minute is controlled to be 12wt% of the total amount of the core monomer pre-emulsion. After the addition is completed, the mixture is stirred at 78° C. for 65 minutes to obtain a core emulsion.

[0117] The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate, and crosslinking agent is 80:1.1:0.35:22:22:1.1;

[0118] The emulsifier is sodium lauryl sulfate;

[0119] The cross-linking agent is divinylbenzene;

[0120] The initiator is potassium persulfate;

[0121] The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:1.1.

[0122] (3) Preparation of emulsion containing mantle layer

[0123] Butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a mantle layer emulsion, and the temperature is controlled to be 78° C. The core emulsion is slowly added to the mantle layer emulsion, and the amount added per minute is controlled to be 12wt% of the total amount of the core emulsion. After the addition is completed, stirring is continued for 100 minutes to obtain an emulsion containing a mantle layer;

[0124] The mass ratio of butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 16:11:27:90:1.1:0.65:1.1;

[0125] The emulsifier is sodium lauryl sulfate;

[0126] The cross-linking agent is divinylbenzene;

[0127] The initiator is potassium persulfate;

[0128] The mass ratio of the core emulsion to the mantle emulsion is 1:1.85.

[0129] (4) Preparation of ACR resin

[0130] Glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a shell emulsion, the temperature is controlled to be 82° C., the shell emulsion is slowly added to the emulsion containing the mantle layer, and the amount added per minute is controlled to be 12wt% of the total amount of the shell emulsion. After the addition is completed, stirring is continued for 100 minutes to obtain a final emulsion, and the final emulsion is spray-dried to obtain an ACR resin;

[0131] The mass ratio of the glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and cross-linking agent is 11:27:16:85:1.1:0.55:1.1;

[0132] The emulsifier is sodium lauryl sulfate;

[0133] The cross-linking agent is divinylbenzene;

[0134] The initiator is potassium persulfate;

[0135] The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:3.25;

[0136] The preparation method of the vinyl modified chitosan is:

[0137] Chitosan and N,N-dimethylformamide are mixed and stirred to dissolve to obtain a chitosan solution, 4-pyrrolidinopyridine is added to the chitosan solution as a catalyst, and then allyl hydroxyethyl ether is added, the temperature is controlled to 75° C., and the reaction is stirred for 40 hours. After the reaction is completed, the chitosan is precipitated with anhydrous ethanol, and then filtered, washed, and dried to obtain vinyl-modified chitosan;

[0138] The mass ratio of chitosan to N,N-dimethylformamide is 1:30;

[0139] The amount of 4-pyrrolidinopyridine is 0.55wt% of the mass of chitosan;

[0140] The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:4.25.

[0141] Comparative Example 1

[0142] The difference from Example 1 is that the steps for preparing the ACR resin are changed to the following operations:

[0143] Glycidyl methacrylate, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a shell emulsion, the temperature is controlled to be 80° C., the shell emulsion is slowly added to the emulsion containing the mantle layer, and the amount added per minute is controlled to be 10wt% of the total amount of the shell emulsion. After the addition is completed, stirring is continued for 120 minutes to obtain a final emulsion, and the final emulsion is spray-dried to obtain an ACR resin;

[0144] The mass ratio of glycidyl methacrylate, methyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 25:25:80:1:0.5:1;

[0145] The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:3;

[0146] The remaining steps were the same to prepare ACR resin.

[0147] Comparative Example 2

[0148] The difference from Example 1 is that the step of preparing the emulsion containing the mantle layer is omitted, and the remaining steps are changed to the following operations:

[0149] (1) Preparation of ACR seed emulsion

[0150] Butyl acrylate, methyl methacrylate, deionized water, emulsifier and crosslinking agent were mixed evenly, then heated to 72°C, initiator was added and mixed evenly, the temperature was kept constant and stirred for 30 minutes, and ACR seed emulsion was obtained after stirring and emulsification;

[0151] The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 25:15:80:1:1:0.5;

[0152] The emulsifier is sodium lauryl sulfate;

[0153] The cross-linking agent is divinylbenzene;

[0154] The initiator is potassium persulfate.

[0155] (2) Preparation of nuclear emulsion

[0156] Deionized water, an emulsifier, and an initiator are mixed and stirred evenly, and then butyl acrylate, methyl methacrylate, and a crosslinking agent are added thereto, and the temperature is controlled to be 75° C. and stirred for 25 minutes to obtain a core monomer pre-emulsion. The core monomer pre-emulsion is then gradually added dropwise to the ACR seed emulsion, and the amount added per minute is controlled to be 10wt% of the total amount of the core monomer pre-emulsion. After the addition is completed, the mixture is stirred at 80° C. for 60 minutes to obtain a core emulsion.

[0157] The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate and crosslinking agent is 75:1:0.3:20:20:1;

[0158] The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:1.

[0159] (3) Preparation of ACR resin

[0160] Glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent are uniformly mixed to obtain a shell emulsion, the temperature is controlled to be 80° C., the shell emulsion is slowly added to the core emulsion, and the amount added per minute is controlled to be 10wt% of the total amount of the core emulsion. After the addition is completed, stirring is continued for 120 minutes to obtain a final emulsion, and the final emulsion is spray-dried to obtain an ACR resin;

[0161] The mass ratio of the glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and cross-linking agent is 10:25:15:80:1:0.5:1;

[0162] The mass ratio of the shell emulsion to the core emulsion is 1:1.8;

[0163] The preparation method of the vinyl modified chitosan is:

[0164] Chitosan and N,N-dimethylformamide are mixed and stirred to dissolve to obtain a chitosan solution, 4-pyrrolidinopyridine is added to the chitosan solution as a catalyst, and then allyl hydroxyethyl ether is added, the temperature is controlled to 70°C, and the reaction is stirred for 36 hours. After the reaction is completed, the chitosan is precipitated with anhydrous ethanol, and then filtered, washed, and dried to obtain vinyl-modified chitosan;

[0165] The mass ratio of chitosan to N,N-dimethylformamide is 1:25;

[0166] The amount of 4-pyrrolidinopyridine is 0.5wt% of the mass of chitosan;

[0167] The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:4.

[0168] Test Example 1 Test on the influence of bending properties of polycarbonate

[0169] The ACR resins prepared in Examples 1-3 and Comparative Examples 1-2 were blended with polycarbonate, respectively. The ratio of ACR resin added was 4.5 wt % of the total mass of polycarbonate. After the samples were prepared by blending, the flexural strength and flexural modulus of the samples were tested according to the method in GB / T9341-2008. The results are shown in Table 1.

[0170] Table 1

[0171]

[0172] In Example 1-3, chitosan is vinyl-modified and used as a component of the ACR resin shell layer. At the same time, the structure of the ACR resin is designed to be a three-layer structure of core layer-mantle layer-shell layer, which can improve the bending properties of the material, and the bending strength and bending modulus are both high;

[0173] In Comparative Example 1, the vinyl-modified chitosan component is omitted from the shell layer of the ACR resin, and the prepared ACR resin has poor improvement on the bending properties of polycarbonate, and the bending strength and bending modulus decrease to a certain extent;

[0174] In Comparative Example 2, the ACR resin was changed to a double-layer structure of a core layer and a shell layer. The prepared ACR resin had poor improvement on the bending properties of polycarbonate, and the bending strength and bending modulus decreased to a large extent.

[0175] Test Example 2: Test on the impact resistance of polycarbonate

[0176] The ACR resin prepared in Example 1-3 and Comparative Example 1-2 was blended with polycarbonate. The ratio of ACR resin added was 4.5wt% of the total mass of polycarbonate. After the samples were prepared by blending, the impact strength of the samples was tested according to the method in GB / T1043.1-2008. The results are shown in Table 2.

[0177] Table 2

[0178]

[0179] In Example 1-3, chitosan is vinyl-modified and used as a component of the ACR resin shell layer. At the same time, the structure of the ACR resin is designed to be a three-layer structure of core layer-mantle layer-shell layer, which can improve the impact resistance of the material and has a high impact strength;

[0180] In Comparative Example 1, the vinyl-modified chitosan component is omitted from the shell layer of the ACR resin, and the prepared ACR resin has poor improvement on the impact resistance of polycarbonate, and the impact strength decreases to a large extent;

[0181] In Comparative Example 2, the ACR resin was changed to a double-layer structure of a core layer and a shell layer. The prepared ACR resin had poor improvement on the impact resistance of polycarbonate, and the impact strength decreased to a certain extent.

[0182] Test Example 3: Test on the influence of tensile properties of polycarbonate

[0183] The ACR resin prepared in Example 1-3 and Comparative Example 1-2 was blended with polycarbonate. The ratio of ACR resin added was 4.5wt% of the total mass of polycarbonate. After the samples were prepared by blending, the tensile strength and tensile modulus of the samples were tested according to the method in GB / T1040.1-2018. The results are shown in Table 3.

[0184] Table 3

[0185]

[0186] In Example 1-3, chitosan is vinyl-modified and used as a component of the ACR resin shell layer. At the same time, the structure of the ACR resin is designed to be a three-layer structure of core layer-mantle layer-shell layer, which can improve the tensile properties of the material, and the tensile strength and tensile modulus are both high;

[0187] In Comparative Example 1, the vinyl-modified chitosan component is omitted from the shell layer of the ACR resin, and the prepared ACR resin has poor improvement on the tensile properties of polycarbonate, and the tensile strength and tensile modulus decrease to a certain extent;

[0188] In Comparative Example 2, the ACR resin was changed to a double-layer structure of a core layer and a shell layer. The prepared ACR resin had poor improvement on the tensile properties of polycarbonate, and the tensile strength and tensile modulus decreased to a large extent.

[0189] Test Example 4: Test on the performance change of polycarbonate under wet heat state

[0190] The ACR resin prepared in Example 1-3 and Comparative Example 1-2 was blended with polycarbonate, and the ratio of ACR resin added was 4.5wt% of the total mass of polycarbonate. After the samples were prepared by blending, the samples were placed in a constant temperature and humidity environment at a temperature of 85°C and a relative humidity of 85%. The placement time was 504h, 1008h, and 1512h, respectively. The performance changes of different samples after different placement time were tested, including the tests of tensile strength, elongation at break, and impact strength. The results are shown in Table 4.

[0191] Table 4

[0192]

[0193] In Example 1-3, chitosan is vinyl-modified and used as a component of the ACR resin shell layer. At the same time, the structure of the ACR resin is designed to be a three-layer structure of core layer-mantle layer-shell layer, which can improve the material's resistance to wet heat aging. After wet heat aging, it can still maintain high tensile strength, elongation at break and impact strength;

[0194] In Comparative Example 1, the vinyl-modified chitosan component is omitted from the shell layer of the ACR resin, and the prepared ACR resin has poor improvement on the wet heat aging resistance of polycarbonate. After wet heat aging, the tensile strength, elongation at break and impact strength all show a relatively serious decrease;

[0195] In comparative example 2, the ACR resin was changed to a double-layer structure of a core layer and a shell layer. The prepared ACR resin had poor improvement on the resistance to moist heat aging of polycarbonate. After moist heat aging, the tensile strength, elongation at break and impact strength all decreased to a large extent.

[0196] Test Example 5: Test on the Effect of Water Boiling Aging Performance of Polycarbonate

[0197] The ACR resin prepared in Example 1-3 and Comparative Example 1-2 was blended with polycarbonate, and the ratio of ACR resin added was 4.5wt% of the total mass of polycarbonate. After the samples were prepared by blending, the samples were subjected to a water boiling aging test in constant temperature water at a temperature of 70°C. The water boiling aging times were 21d, 35d, and 60d, respectively. The changes in the performance of different samples after different water boiling aging times were tested, including the tests of elongation at break and impact strength. The results are shown in Table 5.

[0198] Table 5

[0199]

[0200] In Example 1-3, chitosan is vinyl-modified and used as a component of the ACR resin shell layer. At the same time, the structure of the ACR resin is designed to be a three-layer structure of core layer-mantle layer-shell layer, which can improve the water boiling aging resistance of the material. After water boiling aging, it can still maintain a high elongation at break and impact strength;

[0201] In Comparative Example 1, the vinyl-modified chitosan component is omitted from the shell layer of the ACR resin, and the prepared ACR resin has poor improvement on the water boiling aging resistance of polycarbonate. After water boiling aging, the elongation at break and the impact strength both drop significantly.

[0202] In comparative example 2, the ACR resin was changed to a double-layer structure of a core layer and a shell layer. The prepared ACR resin had poor improvement on the water boiling aging resistance of polycarbonate. After water boiling aging, the elongation at break and the impact strength both decreased to a large extent.

Claims

1. A method for preparing a core-shell structure ACR resin, characterized in that: The preparation method comprises preparing an ACR seed emulsion, preparing a core emulsion, preparing an emulsion containing a mantle layer, and preparing an ACR resin; The method for preparing the ACR seed emulsion is to mix butyl acrylate, methyl methacrylate, deionized water, an emulsifier, and a crosslinking agent, raise the temperature, then add an initiator, and stir while keeping the temperature constant to obtain the ACR seed emulsion; The method for preparing the core emulsion is to mix deionized water, an emulsifier, and an initiator and stir them evenly, then add butyl acrylate, methyl methacrylate, and a crosslinking agent thereto and stir them, to obtain a core monomer pre-emulsion after stirring, and then gradually drop the core monomer pre-emulsion into the ACR seed emulsion to obtain the core emulsion after stirring; The method for preparing the emulsion containing the mantle layer comprises: uniformly mixing butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent to obtain a mantle layer emulsion, slowly adding the core emulsion into the mantle layer emulsion, and then stirring to obtain the emulsion containing the mantle layer; The method for preparing the ACR resin comprises: uniformly mixing glycidyl methacrylate, vinyl-modified chitosan, methyl methacrylate, deionized water, an emulsifier, an initiator, and a crosslinking agent to obtain a shell layer emulsion; slowly adding the shell layer emulsion to an emulsion containing a mantle layer; stirring to obtain a final emulsion; and spray drying the final emulsion to obtain the ACR resin; The preparation method of the vinyl modified chitosan is: Chitosan is mixed with N,N-dimethylformamide to obtain a chitosan solution, 4-pyrrolidinopyridine is added as a catalyst, and then allyl hydroxyethyl ether is added to carry out stirring reaction. After the reaction is completed, the chitosan is precipitated with anhydrous ethanol, and then filtered, washed, and dried to obtain vinyl-modified chitosan.

2. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the method for preparing the ACR seed emulsion, the temperature is raised to 70-75° C., and the stirring time after adding the initiator is 25-35 min; The mass ratio of butyl acrylate, methyl methacrylate, deionized water, emulsifier, crosslinking agent and initiator is 23-27:14-16:75-85: 0.9-1.1:0.9-1.1:0.45-0.55。 3. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the method for preparing the core emulsion, after adding butyl acrylate, methyl methacrylate and a crosslinking agent, the stirring method is to control the temperature to 72-78° C. and stir for 20-30 minutes; after gradually dropping the core monomer pre-emulsion into the ACR seed emulsion, the stirring method is to stir at 78-82° C. for 55-65 minutes; The mass ratio of the deionized water, emulsifier, initiator, butyl acrylate, methyl methacrylate and crosslinking agent is 70-80: 0.9-1.1:0.25-0.35:18-22:18-22:0.9-1.1； When gradually adding the core monomer pre-emulsion to the ACR seed emulsion, the amount added per minute should be controlled to be 8-12wt% of the total amount of the core monomer pre-emulsion; The mass ratio of the ACR seed emulsion to the core monomer pre-emulsion is 1:0.9-1.

1.

4. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the method for preparing an emulsion containing a mantle layer, when the core emulsion is slowly added to the mantle layer emulsion, the temperature needs to be controlled at 72-78° C., and after the core emulsion is slowly added to the mantle layer emulsion, the stirring time is 100-130 minutes; The mass ratio of butyl acrylate, methyl methacrylate, glycidyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 14-16:9-11:23-27:80-90:0.9-1.1:0.55-0.65:0.9-1.1; When the core emulsion is slowly added to the mantle layer emulsion, the amount added per minute needs to be controlled to be 8-12wt% of the total amount of the core emulsion; The mass ratio of the core emulsion to the mantle emulsion is 1:1.75-1.

85.

5. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the method for preparing the ACR resin, when the shell layer emulsion is slowly added to the emulsion containing the mantle layer, the temperature needs to be controlled at 77-82° C., and after the shell layer emulsion is slowly added to the emulsion containing the mantle layer, the stirring time is 100-130 minutes; The mass ratio of the glycidyl methacrylate, vinyl modified chitosan, methyl methacrylate, deionized water, emulsifier, initiator and crosslinking agent is 9-11:23-27:14-16:75-85: 0.9-1.1:0.45-0.55:0.9-1.1； When the shell layer emulsion is slowly added to the emulsion containing the mantle layer, the amount added per minute needs to be controlled to be 8-12wt% of the total amount of the shell layer emulsion; The mass ratio of the shell layer emulsion to the emulsion containing the mantle layer is 1:2.75-3.

25.

6. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the method for preparing ACR seed emulsion, the method for preparing core emulsion, the method for preparing emulsion containing mantle layer and the method for preparing ACR resin, the emulsifier is sodium dodecyl sulfate, the crosslinking agent is divinylbenzene and the initiator is potassium persulfate.

7. The method for preparing a core-shell structure ACR resin according to claim 1, characterized in that: In the preparation method of the vinyl-modified chitosan, the stirring reaction method is to control the temperature to 65-75° C., carry out the stirring reaction, and the reaction time is 32-40 hours; The mass ratio of chitosan to N,N-dimethylformamide is 1:20-30; The amount of 4-pyrrolidinopyridine is 0.45-0.55wt% of the chitosan mass; The mass ratio of the allyl hydroxyethyl ether to chitosan is 1:3.75-4.25.

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