High-strength heat-resistant polycarbonate film and method for manufacturing the same

Abstract

The application discloses a preparation method of high-strength heat-resistant polycarbonate film, and the preparation steps comprise the following steps: (1) preparing a graphene-cellulose compound; (2) alkylating the graphene-cellulose compound, and then adding tea polyphenol modification treatment to obtain a modified compound; (3) performing activation treatment on the modified compound, and then adding glycidyl methacrylate to obtain a filler powder; (4) mixing the filler powder, ABS high-gum powder and dried polycarbonate to form a mixture, melting and granulating the mixture to obtain granules, and blow molding the granules after drying to obtain the high-strength heat-resistant polycarbonate film. The polycarbonate film prepared by the method has good strength and heat resistance, and has relatively high tensile strength and heat distortion temperature, thereby improving the durability of the polycarbonate film.

Description

Technical Field

[0001] This invention relates to the field of polycarbonate film materials technology, and in particular to a high-strength heat-resistant polycarbonate film and its preparation method. Background Technology

[0002] Polycarbonate (PC) possesses advantages such as high melting point, low-temperature resistance, aging resistance, low water absorption, and resistance to inorganic and dilute organic acids, making it widely used in automotive, pharmaceutical, packaging, construction, and electronics industries. However, polycarbonate also suffers from drawbacks such as poor environmental resistance and relatively low mechanical properties. With the increasing application of polycarbonate in the construction and chemical industries, the requirements for its mechanical and heat resistance properties are becoming increasingly stringent, necessitating modification to improve its overall performance. Therefore, overcoming these performance defects of polycarbonate through effective modification methods has significant theoretical and practical implications. Among various modification methods, modification using nanoparticles has attracted widespread attention due to its low cost, ease of operation, and high versatility. Summary of the Invention

[0003] Therefore, the present invention provides a method for preparing a high-strength, heat-resistant polycarbonate film, the preparation steps of which include:

[0004] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the dispersion is heated in a water bath to 75±10℃ and kept warm, then triethylenetetramine and alkali are added, and the mixture is stirred and kept warm after the addition. Then carboxymethyl cellulose is added and mixed evenly. 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, and the mixture is kept warm at 75±10℃ for another reaction. After the reaction, the solid and liquid are separated, the solid phase is washed, and the mixture is dried to obtain a graphene-cellulose composite.

[0005] (2) The graphene-cellulose composite is dispersed in anhydrous ethanol to form an alcohol suspension; the alcohol suspension is heated in a water bath and kept warm, and then γ-aminopropyltriethoxysilane is added to the alcohol suspension to alkylate the surface of the graphene-cellulose composite. After alkylation, tea polyphenols are added, and the mixture is stirred in a water bath at a constant temperature for further modification. After the modification, the solid and liquid phases are separated, the solid phase is washed, and the mixture is dried to obtain the modified composite.

[0006] (3) The modified compound was added to deionized water and stirred to disperse it to obtain an aqueous suspension; then potassium permanganate and citric acid were added to the aqueous suspension, and the mixture was activated in a water bath at a constant temperature after the addition. After the activation treatment, glycidyl methacrylate was added and the mixture was stirred in a water bath at a constant temperature. After stirring, the solid and liquid were separated, the solid phase was washed and dried to obtain filler powder.

[0007] (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture, the mixture is melted and granulated to obtain granules, and the granules are dried and blow-molded to obtain the high-strength heat-resistant polycarbonate film.

[0008] Further, in step (1), the mass ratio of the graphene oxide dispersed in deionized water is graphene oxide:deionized water = 1g:20-30g; the ratio of the amount of triethylenetetramine, alkali, carboxymethyl cellulose, 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide added to the amount of graphene oxide added to prepare the dispersion is triethylenetetramine:alkali:carboxymethyl cellulose:1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride:N-hydroxysuccinimide:graphene oxide = 6-10g:1-2g:1-1.5g:0.1-0.15g:0.1-0.15g:1g; the alkali is sodium hydroxide.

[0009] Further, in step (2), the ratio of the graphene-cellulose complex dispersed in anhydrous ethanol is graphene-cellulose complex: anhydrous ethanol = 1g: 50-100mL, and the ratio of the mass of γ-aminopropyltriethoxysilane and tea polyphenols added to the alcohol suspension to the mass of graphene-cellulose complex added to prepare the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 2-3mL: 0.6-0.8g: 1g.

[0010] Furthermore, in step (2), the water bath is heated to 65±3℃ and kept at that temperature, during which condensation and reflux occur.

[0011] Further, in step (3), the ratio of the modified complex to deionized water and stirred to obtain an aqueous suspension is modified complex: deionized water = 1g: 50-100mL; the ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of modified complex added to prepare the aqueous suspension is potassium permanganate: citric acid: glycidyl methacrylate: modified complex = 0.8-0.9g: 0.2-0.4g: 4-5g: 1g.

[0012] Furthermore, in step (3), the activation treatment temperature is 60±5℃ and the treatment time is 1~2h.

[0013] Furthermore, in step (4), each raw material is 3-5 parts by weight of filler powder; 30 parts of ABS high-adhesion powder; and 70 parts of polycarbonate.

[0014] The beneficial effects of this invention are as follows: the polycarbonate film prepared by the method described in this invention has good strength and heat resistance, exhibiting relatively high tensile strength and heat distortion temperature, thus improving the durability of the polycarbonate film. This invention first uses an amidation reaction to connect the amino groups in triethylenetetramine to the carboxyl groups on the surfaces of graphene oxide and carboxymethyl cellulose, forming a graphene-cellulose composite. After alkylation, it is modified with tea polyphenols. The introduced phenolic hydroxyl groups can form a hydrogen bond network with the ester bonds in the polycarbonate matrix molecules, improving the compatibility between the filler particles and the polycarbonate matrix, enhancing the interfacial bonding force, and improving the overall stability and strength of the polycarbonate film. Subsequently, free radicals are formed through activation with potassium permanganate and citric acid, followed by grafting glycidyl methacrylate to introduce epoxy groups. During melt mixing, these epoxy groups can interact with the carboxyl and hydroxyl groups in the polycarbonate molecules, further improving the compatibility between the filler and the matrix. Furthermore, the modified filler has improved dispersibility, allowing it to act as a crosslinking node in the polycarbonate matrix, resulting in a more uniform stress distribution during stress, which is beneficial for improving strength. Attached Figure Description

[0015] Figure 1 Photograph of the polycarbonate film prepared by the method described in Example 3. Detailed Implementation

[0016] The present invention will be further described below with reference to the embodiments.

[0017] Example 1

[0018] A method for preparing a high-strength, heat-resistant polycarbonate film, comprising the following steps:

[0019] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour until homogeneous. 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3- The ratio of the amounts of dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 6 g: 1 g: 1 g: 0.1 g: 0.1 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0020] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite to anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, with reflux during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and after addition, the mixture was stirred at 65°C for 2 hours to alkylate the surface of the graphene-cellulose composite; after alkylation, γ-aminopropyltriethoxysilane was added. Add tea polyphenols, and add γ-aminopropyltriethoxysilane to the alcohol suspension. The mass ratio of tea polyphenols to the amount of graphene-cellulose complex added to the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 2 mL: 0.6 g: 1 g. After adding the materials, continue stirring at a constant temperature of 65°C in a water bath for 10 h for modification treatment. After treatment, separate the solid and liquid phases. Wash the solid phase twice with ethanol and then twice with deionized water. Dry it at 80°C for 4 h to obtain the modified complex.

[0021] (3) The modified complex was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified complex to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the mixture was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to the aqueous suspension was 0.8 g: 0.2 g: 4 g: 1 g. After the addition, the mixture was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0022] (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 3 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the high-strength heat-resistant polycarbonate film.

[0023] Example 2

[0024] A method for preparing a high-strength, heat-resistant polycarbonate film, comprising the following steps:

[0025] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour to achieve uniform mixing. 1-Ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride. The ratio of the amounts of 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 8 g: 1 g: 1.2 g: 0.12 g: 0.12 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0026] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite to anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, with reflux during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and after addition, the mixture was stirred at 65°C for 2 hours to alkylate the surface of the graphene-cellulose composite; after alkylation, γ-aminopropyltriethoxysilane was added. Add tea polyphenols, and add γ-aminopropyltriethoxysilane to the alcohol suspension. The mass ratio of tea polyphenols to the amount of graphene-cellulose complex added to the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 2 mL: 0.7 g: 1 g. After adding the materials, continue stirring at a constant temperature of 65°C in a water bath for 10 h for modification treatment. After treatment, separate the solid and liquid phases. Wash the solid phase twice with ethanol and then twice with deionized water. Dry it at 80°C for 4 h to obtain the modified complex.

[0027] (3) The modified complex was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified complex to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the mixture was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to the aqueous suspension was 0.8 g: 0.3 g: 4 g: 1 g. After the addition, the mixture was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0028] (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 4 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the high-strength heat-resistant polycarbonate film.

[0029] Example 3

[0030] A method for preparing a high-strength, heat-resistant polycarbonate film, comprising the following steps:

[0031] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour to achieve uniform mixing. 1-Ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride. The ratio of the amounts of 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 8 g: 2 g: 1.4 g: 0.13 g: 0.13 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0032] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite to anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, with reflux during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and after addition, the mixture was stirred at 65°C for 2 hours to alkylate the surface of the graphene-cellulose composite; after alkylation, γ-aminopropyltriethoxysilane was added. Add tea polyphenols, and add γ-aminopropyltriethoxysilane to the alcohol suspension. The mass ratio of tea polyphenols to the amount of graphene-cellulose complex added to the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 3 mL: 0.7 g: 1 g. After adding the materials, continue stirring at a constant temperature of 65°C in a water bath for 10 h for modification treatment. After treatment, separate the solid and liquid phases. Wash the solid phase twice with ethanol and then twice with deionized water. Dry it at 80°C for 4 h to obtain the modified complex.

[0033] (3) The modified complex was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified complex to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the mixture was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to the aqueous suspension was 0.9 g: 0.3 g: 5 g: 1 g. After the addition, the mixture was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0034] (4) The filler powder, ABS high-rubber powder, and dried polycarbonate are mixed to form a mixture. The raw materials are, by weight, 4 parts filler powder, 30 parts ABS high-rubber powder, and 70 parts polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240, and 250°C, respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours, and then blow-molded to obtain the high-strength, heat-resistant polycarbonate film, such as... Figure 1 As shown.

[0035] Example 4

[0036] A method for preparing a high-strength, heat-resistant polycarbonate film, comprising the following steps:

[0037] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour to achieve uniform mixing. 1-Ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride. The ratio of the amounts of 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 10 g: 2 g: 1.5 g: 0.15 g: 0.15 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0038] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite to anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, with reflux during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and after addition, the mixture was stirred at 65°C for 2 hours to alkylate the surface of the graphene-cellulose composite; after alkylation, γ-aminopropyltriethoxysilane was added. Add tea polyphenols, and add γ-aminopropyltriethoxysilane to the alcohol suspension. The mass ratio of tea polyphenols to the amount of graphene-cellulose complex added to the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 3 mL: 0.8 g: 1 g. After adding the materials, continue stirring at a constant temperature of 65°C in a water bath for 10 h for modification treatment. After treatment, separate the solid and liquid phases. Wash the solid phase twice with ethanol and then twice with deionized water. Dry it at 80°C for 4 h to obtain the modified complex.

[0039] (3) The modified complex was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified complex to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the mixture was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to the aqueous suspension was 0.9 g: 0.4 g: 5 g: 1 g. After the addition, the mixture was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0040] (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 5 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the high-strength heat-resistant polycarbonate film.

[0041] Comparative Example 1

[0042] A comparative method for preparing a polycarbonate film includes the following steps:

[0043] (1) Graphene oxide was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the amount of graphene oxide dispersed in anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, and refluxed during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and the mixture was stirred at 65°C for 2 h after the addition to alkylate the surface of the graphene oxide; after alkylation, tea polyphenols were added; the mass ratio of the amount of γ-aminopropyltriethoxysilane and tea polyphenols added to the alcohol suspension to the amount of graphene oxide added to the prepared alcohol suspension was γ-aminopropyltriethoxysilane: tea polyphenols: graphene oxide = 3 mL: 0.7 g: 1 g; after the addition, the mixture was stirred at 65°C in a water bath for 10 h to carry out the modification treatment; after the treatment, the solid and liquid phases were separated, the solid phase was washed twice with ethanol and then twice with deionized water, and dried at 80°C for 4 h to obtain the modified product.

[0044] (2) The modified material was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified material to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the suspension was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified material added to prepare the aqueous suspension was 0.9 g: 0.3 g: 5 g: 1 g. After the addition, the suspension was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0045] (3) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 4 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the polycarbonate film of this comparative example.

[0046] Comparative Example 2

[0047] A comparative method for preparing a polycarbonate film includes the following steps:

[0048] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour to achieve uniform mixing. 1-Ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride. The ratio of the amounts of 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 8 g: 2 g: 1.4 g: 0.13 g: 0.13 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0049] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite dispersed in anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, and refluxed during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and the mixture was stirred at 65°C for 2 h after the addition to alkylate the surface of the graphene-cellulose composite; the ratio of the mass of γ-aminopropyltriethoxysilane added to the alcohol suspension to the mass of the graphene-cellulose composite added to the preparation of the alcohol suspension was 3 mL: 1 g; after alkylation, the solid and liquid phases were separated, the solid phase was washed twice with ethanol and then twice with deionized water, and dried at 80°C for 4 h to obtain the modified composite.

[0050] (3) The modified complex was added to deionized water and stirred to disperse it to obtain an aqueous suspension. The ratio of the modified complex to deionized water was 1 g: 50 mL. Potassium permanganate and citric acid were then added to the aqueous suspension. After the addition, the mixture was heated to 60°C in a water bath and stirred for 1 hour for activation treatment. After activation treatment, glycidyl methacrylate was added. The ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to the aqueous suspension was 0.9 g: 0.3 g: 5 g: 1 g. After the addition, the mixture was stirred at 60°C in a water bath for 1 hour. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with acetone and then twice with deionized water. It was dried at 80°C for 4 hours to obtain filler powder.

[0051] (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 4 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the polycarbonate film of this comparative example.

[0052] Comparative Example 3

[0053] A comparative method for preparing a polycarbonate film includes the following steps:

[0054] (1) Graphene oxide is dispersed in deionized water to form a dispersion; the mass ratio of graphene oxide to deionized water is 1g:20g; the dispersion is heated to 75°C in a water bath and kept at that temperature, then triethylenetetramine and sodium hydroxide are added, and the mixture is stirred at 75°C for 8 hours after addition. Then, carboxymethyl cellulose is added while stirring, and the mixture is stirred for 1 hour to achieve uniform mixing. 1-Ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, along with triethylenetetramine, alkali, carboxymethyl cellulose, and 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride. The ratio of the amounts of 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion was triethylenetetramine: base: carboxymethyl cellulose: 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride: N-hydroxysuccinimide: graphene oxide = 8 g: 2 g: 1.4 g: 0.13 g: 0.13 g: 1 g; then the mixture was stirred at 75 °C for 10 h. After stirring, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and twice with deionized water, and then dried at 80 °C for 4 h to obtain the graphene-cellulose complex.

[0055] (2) The graphene-cellulose composite was dispersed in anhydrous ethanol to form an alcohol suspension; the ratio of the graphene-cellulose composite to anhydrous ethanol was 1 g: 50 mL; the alcohol suspension was heated to 65°C in a water bath and kept at that temperature, with reflux during the heating process; then γ-aminopropyltriethoxysilane was added to the alcohol suspension, and the mixture was stirred at 65°C for 2 hours after addition to alkylate the surface of the graphene-cellulose composite; after alkylation, tea was added. Polyphenols were added to the alcohol suspension. The mass ratio of γ-aminopropyltriethoxysilane and tea polyphenols to the graphene-cellulose complex added to the alcohol suspension was γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 3 mL: 0.7 g: 1 g. After addition, the mixture was stirred at a constant temperature of 65°C in a water bath for 10 h for modification treatment. After treatment, the solid and liquid phases were separated. The solid phase was washed twice with ethanol and then twice with deionized water. It was then dried at 80°C for 4 h to obtain the filler powder of this comparative example.

[0056] (3) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture. The raw materials are 4 parts by weight of filler powder, 30 parts of ABS high-rubber powder and 70 parts of polycarbonate. The mixture is melt-granulated in an extruder to obtain granules. The temperatures of the three zones of the extruder are 230, 240 and 250°C respectively. The granules are dried in a vacuum drying oven at 80°C for 4 hours and then blow-molded to obtain the polycarbonate film of this comparative example.

[0057] Example 5

[0058] The tensile strength of the polycarbonate films prepared by the methods described in the above embodiments and comparative examples was tested according to the requirements of standard GB / T 1040.3-2006. The specimen type was type 2 (15 mm wide), the testing speed was 50 mm / min, and the clamp spacing was 100 mm. The heat distortion temperature of the polycarbonate films prepared by the methods described in the above embodiments and comparative examples was tested according to ISO-75-2:2013 A method. The pressure was set to 1.80 MPa, and the heating rate was 120 °C / h. The results are shown in Table 1.

[0059] As shown in Table 1, the polycarbonate film prepared by the method described in this invention exhibits good strength and heat resistance, with relatively high tensile strength and heat distortion temperature, thus improving the durability of the polycarbonate film. This invention first uses an amidation reaction to connect the amino groups in triethylenetetramine to the carboxyl groups on the surfaces of graphene oxide and carboxymethyl cellulose, forming a graphene-cellulose composite. After alkylation, it is modified with tea polyphenols. The introduced phenolic hydroxyl groups can form a hydrogen bond network with the ester bonds in the polycarbonate matrix molecules, improving the compatibility between the filler particles and the polycarbonate matrix, enhancing the interfacial bonding force, and improving the overall stability and strength of the polycarbonate film. Subsequently, free radicals are formed through activation with potassium permanganate and citric acid, followed by grafting glycidyl methacrylate to introduce epoxy groups. During melt mixing, these epoxy groups can interact with the carboxyl and hydroxyl groups in the polycarbonate molecules, further improving the compatibility between the filler and the matrix. Furthermore, the modified filler has improved dispersibility, allowing it to act as a crosslinking node in the polycarbonate matrix, resulting in a more uniform stress distribution during stress, which is beneficial for improving strength.

[0060] Table 1

[0061]

[0062] The technical solutions provided by the present invention have been described in detail above. For those skilled in the art, there will be changes in specific implementation methods and application scope based on the ideas of the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing a high-strength, heat-resistant polycarbonate film, characterized in that, The preparation steps include: (1) Graphene oxide is dispersed in deionized water to form a dispersion; the dispersion is heated in a water bath to 75±10℃ and kept warm, then triethylenetetramine and alkali are added, and the mixture is stirred and kept warm after the addition. Then carboxymethyl cellulose is added and mixed evenly. 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide are added, and the mixture is kept warm at 75±10℃. After the reaction, the solid and liquid are separated, the solid phase is washed, and dried to obtain a graphene-cellulose composite. (2) The graphene-cellulose composite is dispersed in anhydrous ethanol to form an alcohol suspension; the alcohol suspension is heated in a water bath and kept warm, and then γ-aminopropyltriethoxysilane is added to the alcohol suspension to alkylate the surface of the graphene-cellulose composite. After alkylation, tea polyphenols are added, and the mixture is stirred in a water bath at a constant temperature for further modification. After the modification, the solid and liquid phases are separated, the solid phase is washed, and the mixture is dried to obtain the modified composite. (3) The modified complex is added to deionized water and stirred to disperse it to obtain an aqueous suspension; the ratio of the modified complex to deionized water is 1g:50-100mL; then potassium permanganate and citric acid are added to the aqueous suspension, and the mixture is activated in a water bath at a constant temperature after addition. After activation, glycidyl methacrylate is added, and the ratio of the amount of potassium permanganate, citric acid and glycidyl methacrylate added to the amount of the modified complex added to prepare the aqueous suspension is 0.8-0.9g:0.2-0.4g:4-5g:1g; stirring is continued in a water bath at a constant temperature; after stirring, the solid and liquid phases are separated, the solid phase is washed and dried to obtain filler powder; (4) The filler powder, ABS high-rubber powder and dried polycarbonate are mixed to form a mixture, the mixture is melted and granulated to obtain granules, and the granules are dried and blow-molded to obtain the high-strength heat-resistant polycarbonate film.

2. The method for preparing a high-strength heat-resistant polycarbonate film according to claim 1, characterized in that, In step (1), the mass ratio of graphene oxide dispersed in deionized water is 1g:20-30g; the ratio of the amount of triethylenetetramine, alkali, carboxymethyl cellulose, 1-ethyl-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide to the amount of graphene oxide added to prepare the dispersion is 6-10g:1-2g:1-1.5g:0.1-0.15g:0.1-0.15g:1g; the alkali is sodium hydroxide.

3. The method for preparing a high-strength heat-resistant polycarbonate film according to claim 1, characterized in that, In step (2), the ratio of the graphene-cellulose complex dispersed in anhydrous ethanol is graphene-cellulose complex: anhydrous ethanol = 1g: 50-100mL. The ratio of the mass of γ-aminopropyltriethoxysilane and tea polyphenols added to the alcohol suspension to the mass of the graphene-cellulose complex added to prepare the alcohol suspension is γ-aminopropyltriethoxysilane: tea polyphenols: graphene-cellulose complex = 2-3mL: 0.6-0.8g: 1g.

4. The method for preparing a high-strength heat-resistant polycarbonate film according to claim 1, characterized in that, In step (2), the water bath is heated to 65±3℃ and kept at that temperature, during which condensation and reflux occur.

5. The method for preparing a high-strength heat-resistant polycarbonate film according to claim 1, characterized in that, In step (3), the activation treatment temperature is 60±5℃ and the treatment time is 1~2h.

6. The method for preparing a high-strength heat-resistant polycarbonate film according to claim 1, characterized in that, In step (4), each raw material is 3-5 parts by weight of filler powder; 30 parts of ABS high-rubber powder; and 70 parts of polycarbonate.

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