Polyester material based on modified graphene oxide and preparation method thereof

Abstract

The invention discloses a polyester material based on modified graphene oxide and a preparation method thereof, and belongs to the technical field of polyester materials. Comprising the following raw materials in parts by weight: 125-155 parts of polyester chips, 18-34 parts of modified graphene oxide, 7-15 parts of an antibacterial agent and 5-12 parts of a processing aid. Wherein a hydrophobic modification group is connected to a modified graphene oxide molecule, so that the modified graphene oxide has hydrophobicity, better compatibility with polyester and easier performance, the mechanical property and antibacterial property of the polyester material are greatly enhanced, and the modified graphene oxide can also have a synergistic effect with a quaternary ammonium salt antibacterial agent in the raw materials; in addition, the modified graphene oxide molecules also contain phosphite ester groups, so that the oxidation resistance of the polyester material is enhanced. In conclusion, the prepared polyester material has excellent mechanical property, antibacterial property and oxidation resistance, and has important application value in the technical field of polyester materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester materials. Specifically, it relates to a polyester material based on modified graphene oxide and a preparation method thereof. Background Art

[0002] Graphene is a two-dimensional crystal composed of carbon atoms with only one atomic thickness. It is the thinnest material in the world and has excellent electrical, thermal, and mechanical properties. As a newly discovered novel nanomaterial that is the thinnest, strongest, and has the strongest electrical and thermal conductivity, it has potential applications in many fields such as aerospace and military, solar cells, flexible displays, sensors, adsorption, etc. Scientists even predict that graphene will "completely change the 21st century" and is very likely to trigger a disruptive new technology and new industry revolution sweeping the globe.

[0003] Graphene oxide (GO), a derivative of graphene, is a new type of carbon material. It has carboxylic acid functional groups at the edges and hydroxyl and epoxy groups on its surface, and has good dispersibility, hydrophilicity, biocompatibility and other properties. It is regarded as one of the most promising carbon materials in contemporary times.

[0004] Polyester is a general term for polymers obtained by polycondensation of polyols and polyacids. It mainly refers to polyethylene terephthalate (PET). Conventionally, it also includes linear thermoplastic resins such as polybutylene terephthalate (PBT) and polyarylate. Polyester materials have various excellent properties, such as high toughness and strength, and are a class of engineering plastics with excellent performance. Due to its excellent properties, it is also widely used in the packaging industry, electronics and electrical appliances, medical and health, construction, automotive and other fields. However, with the continuous improvement of people's requirements, the requirements for polyester are also getting higher and higher. Therefore, there is research on adding graphene oxide as a raw material to polyester materials to improve the performance of polyester materials. However, graphene oxide is an inorganic non-metallic material and has poor compatibility with organic polyester materials, and is prone to agglomeration in the material, seriously affecting the performance of polyester materials. Therefore, it is urgent to invent a modified graphene oxide with good compatibility with polyester materials to meet the higher requirements in the technical field of polyester materials. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a polyester material based on modified graphene oxide and a preparation method thereof.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A preparation method of a polyester material based on modified graphene oxide includes the following steps:

[0008] The polyester chips are dried. After drying, they are mixed with modified graphene oxide, an antibacterial agent, and a processing aid in a mixer. After being uniformly mixed, they are then added to a twin-screw extruder for melt blending and extrusion to obtain a polyester material based on modified graphene oxide.

[0009] Further, the raw materials are as follows by weight: 125 - 155 parts of polyester chips, 18 - 34 parts of modified graphene oxide, 7 - 15 parts of antibacterial agent, and 5 - 12 parts of processing aid.

[0010] Further, the drying conditions are drying in an oven at 70 - 80 °C for 12 - 24 h.

[0011] Further, the antibacterial agent is a quaternary ammonium salt antibacterial agent.

[0012] Further, the processing aid is one of zinc stearate, calcium stearate, and paraffin.

[0013] A quaternary ammonium salt antibacterial agent is added to the raw materials. The quaternary ammonium ions therein can produce strong electrostatic interaction with negatively charged bacteria due to the positive charges they carry, and have a strong adsorption effect on the bacteria, which can greatly enhance the antibacterial performance of the material; in addition, the added processing aid can play a lubricating role and make the raw materials more uniformly mixed.

[0014] Further, the modified graphene oxide is prepared through the following steps:

[0015] A1. Graphene oxide and deionized water are mixed. After ultrasonic dispersion, silane coupling agent KH-550 is added, and under the condition of 70 °C, condensation reflux is carried out for 8 h. Then, filtration is performed, and the filter residue is washed with anhydrous ethanol and deionized water for multiple times, and then placed in an oven for drying to obtain silane-modified graphene oxide;

[0016] Hydrophobic modification of graphene oxide is carried out using silane coupling agent KH-550 to obtain silane-modified graphene oxide;

[0017] A2. Pentaerythritol, triethylamine (catalyst), and tetrahydrofuran are added to a three-necked flask equipped with a thermometer, a stirrer, and a condenser. Under stirring, phosphorus trichloride is slowly added dropwise, controlling the temperature not to exceed 30 °C. After dropping, the temperature is raised to 55 °C for reflux reaction for 6 h. After the reaction is completed, the solvent tetrahydrofuran and excessive phosphorus trichloride are removed by distillation to obtain intermediate product 1;

[0018] Under the catalysis of triethylamine, 1 mol of pentaerythritol reacts with 2 mol of phosphorus trichloride, and the amount of phosphorus trichloride used is slightly excessive to obtain intermediate product 1; the specific reaction is as follows:

[0019]

[0020] A3. Add the intermediate 1, triethylamine, and tetrahydrofuran into a three-necked flask equipped with a thermometer and a stirring device. After stirring evenly, add stearyl alcohol and gradually raise the temperature until it reaches 70 °C. Keep the temperature for reaction for 9 h. After the reaction is completed, perform vacuum distillation and purification by column chromatography. Rotate and evaporate to remove the eluent to obtain intermediate 2;

[0021] The intermediate 1 and stearyl alcohol undergo an S N nucleophilic substitution reaction. By controlling the molar ratio of the two to be close to 1:1 and the amount of intermediate 1 to be slightly in excess, only 1 mol of stearyl alcohol participates in the reaction to obtain intermediate 2. The specific reaction process is as follows:

[0022]

[0023] A4. Mix the silane-modified graphene oxide and N,N-dimethylformamide, and after ultrasonic treatment for 30 min, add intermediate 2 and triethylamine in sequence. Use a stirrer to stir and mix evenly, maintain the reaction temperature at 75 °C, and keep the temperature for reaction for 10 h. After the reaction is completed, perform vacuum distillation, washing, and freeze-drying to obtain modified graphene oxide;

[0024] Under the catalysis of triethylamine, intermediate 2 reacts with the amino group on the silane-modified graphene oxide to obtain modified graphene oxide.

[0025] Further, in step A1, the dosage ratio of graphene oxide, deionized water, and silane coupling agent KH-550 is 1 g:100 mL:7.3 g.

[0026] Further, in step A2, the dosage ratio of pentaerythritol, triethylamine, tetrahydrofuran, and phosphorus trichloride is 13.6 g:15 mL:100 mL:28.7 g.

[0027] Further, in step A3, the dosage ratio of intermediate 1, triethylamine, tetrahydrofuran, and stearyl alcohol is 27.2 g:15 mL:150 mL:26.9 g.

[0028] Further, in step A4, the dosage ratio of silane-modified graphene oxide, N,N-dimethylformamide, intermediate 2, and triethylamine is 1 g:100 mL:12.1 g:10 mL.

[0029] Graphene oxide has excellent antibacterial and mechanical properties. First, graphene oxide is hydrophobically modified with silane coupling agent KH-550 to increase the compatibility between graphene oxide and polyester matrix. Second, intermediate product 2 is prepared through reaction. The molecule of intermediate product 2 contains a very long carbon chain and has excellent hydrophobic properties. Intermediate product 2 is used to hydrophobically modify graphene oxide again, further enhancing the hydrophobicity of graphene oxide, enabling graphene oxide to be evenly dispersed in the polyester matrix, reducing the agglomeration phenomenon, and fully exerting the properties of graphene oxide, significantly improving the antibacterial and mechanical properties of the matrix. In addition, the modified graphene oxide molecule also contains phosphite functional groups. As a type of antioxidant, phosphite can decompose the hydroperoxides generated by oxidative aging in the polyester matrix into inactive substances, thereby achieving the purpose of terminating or delaying the oxidative degradation of polyester and improving the antioxidant performance of the matrix.

[0030] Advantages of the present invention:

[0031] The present invention prepares modified graphene oxide through a series of reactions and uses it as one of the raw materials to prepare polyester materials. The modified graphene oxide molecule is connected with hydrophobic modification groups, making the modified graphene oxide hydrophobic, having better compatibility with polyester, and being more likely to exert its properties, greatly enhancing the mechanical properties and antibacterial properties of the polyester material. Moreover, it can also act synergistically with the quaternary ammonium salt antibacterial agent in the raw materials to further enhance the antibacterial properties of the polyester. In addition, the modified graphene oxide molecule also contains phosphite groups, enhancing the antioxidant performance of the polyester material. In summary, the polyester material prepared by the present invention has excellent mechanical properties, antibacterial properties, and antioxidant performance, and has important application value in the technical field of polyester materials. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0033] Example 1

[0034] Preparation of modified graphene oxide:

[0035] A1. Mix 1 g of graphene oxide and 100 mL of deionized water, ultrasonically disperse, then add 7.3 g of silane coupling agent KH-550, carry out condensation reflux at 70 °C for 8 h, filter by suction, wash the filter residue with absolute ethanol and deionized water for multiple times, and then put it into an oven to dry to obtain silane-modified graphene oxide;

[0036] A2. Add 13.6 g of pentaerythritol, 15 mL of triethylamine, and 100 mL of tetrahydrofuran into a three-necked flask equipped with a thermometer, a stirrer, and a condenser. While stirring, slowly add 28.7 g of phosphorus trichloride, controlling the temperature not to exceed 30 °C. After the addition, raise the temperature to 55 °C and reflux for 6 h. After the reaction is completed, distill off the solvent tetrahydrofuran and the excess phosphorus trichloride to obtain intermediate 1;

[0037] A3. Add 27.2 g of intermediate 1, 15 mL of triethylamine, and 150 mL of tetrahydrofuran into a three-necked flask equipped with a thermometer and a stirring device. After stirring evenly, add 26.9 g of stearyl alcohol and gradually raise the temperature until it reaches 70 °C. Keep the temperature for 9 h. After the reaction is completed, perform vacuum distillation and column chromatography purification, and rotary evaporate to remove the eluent to obtain intermediate 2;

[0038] A4. Mix 1 g of silane-modified graphene oxide with 100 mL of N,N-dimethylformamide. After ultrasonic treatment for 30 min, add 12.1 g of intermediate 2 and 10 mL of triethylamine in sequence. Using a stirrer, stir and mix evenly, then maintain the reaction temperature at 75 °C and keep the temperature for 10 h. After the reaction is completed, perform vacuum distillation, washing, and freeze-drying to obtain modified graphene oxide.

[0039] Example 2

[0040] Preparation of modified graphene oxide:

[0041] A1. Mix 2 g of graphene oxide and 200 mL of deionized water, and after ultrasonic dispersion, add 14.6 g of silane coupling agent KH-550. Under the condition of 70 °C, carry out condensation reflux for 8 h, perform suction filtration, wash the filter residue with absolute ethanol and deionized water for multiple times, and then put it into an oven to dry to obtain silane-modified graphene oxide;

[0042] A2. Add 27.2 g of pentaerythritol, 30 mL of triethylamine, and 200 mL of tetrahydrofuran into a three-necked flask equipped with a thermometer, a stirrer, and a condenser. While stirring, slowly add 57.4 g of phosphorus trichloride, controlling the temperature not to exceed 30 °C. After the addition, raise the temperature to 55 °C and reflux for 6 h. After the reaction is completed, distill off the solvent tetrahydrofuran and the excess phosphorus trichloride to obtain intermediate 1;

[0043] A3. Add 54.4 g of intermediate 1, 30 mL of triethylamine, and 300 mL of tetrahydrofuran into a three-necked flask equipped with a thermometer and a stirring device. After stirring evenly, add 53.8 g of stearyl alcohol and gradually raise the temperature until it reaches 70 °C. Keep the temperature for 9 h. After the reaction is completed, perform vacuum distillation and column chromatography purification, and rotary evaporate to remove the eluent to obtain intermediate 2;

[0044] A4. Mix 2 g of silane-modified graphene oxide with 200 mL of N,N-dimethylformamide. After ultrasonic treatment for 30 min, sequentially add 24.2 g of intermediate product 2 and 20 mL of triethylamine. Use a stirrer to mix evenly, maintain the reaction temperature at 75 °C, and keep the temperature for 10 h. After the reaction is completed, carry out reduced-pressure distillation, washing, and freeze-drying to obtain modified graphene oxide.

[0045] Example 3

[0046] Dry 125 g of polyester chips in an oven at 70 °C for 12 h. After drying, mix with 18 g of the modified graphene oxide prepared in Example 1, 7 g of a quaternary ammonium salt antibacterial agent (cetyltrimethylammonium bromide), and 5 g of zinc stearate in a mixer. After mixing evenly, add it to a twin-screw extruder for melt blending and extrusion to obtain a polyester material based on modified graphene oxide.

[0047] Example 4

[0048] Dry 140 g of polyester chips in an oven at 80 °C for 24 h. After drying, mix with 26 g of the modified graphene oxide prepared in Example 2, 11 g of a quaternary ammonium salt antibacterial agent (cetyltrimethylammonium bromide), and 8 g of calcium stearate in a mixer. After mixing evenly, add it to a twin-screw extruder for melt blending and extrusion to obtain a polyester material based on modified graphene oxide.

[0049] Example 5

[0050] Dry 155 g of polyester chips in an oven at 80 °C for 24 h. After drying, mix with 34 g of the modified graphene oxide prepared in Example 2, 15 g of a quaternary ammonium salt antibacterial agent (cetyltrimethylammonium bromide), and 12 g of paraffin in a mixer. After mixing evenly, add it to a twin-screw extruder for melt blending and extrusion to obtain a polyester material based on modified graphene oxide.

[0051] Comparative Example 1

[0052] Use unmodified ordinary graphene oxide of the same mass to replace the modified graphene oxide in Example 5, and the remaining steps are the same as in Example 5 to prepare a polyester material.

[0053] Comparative Example 2

[0054] Use commercially available polyester masterbatch.

[0055] Make the samples of Example 3, 4, 5 and Comparative Example 1, 2 into corresponding shapes according to different test standards, and conduct the following performance tests:

[0056] Determine the tensile strength according to the national standard GB / T 1040.3-2006 Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets

[0057] The induction time of the specimen was measured using the national standard GB / T 19466.6-2009 Plastics - Differential scanning calorimetry (DSC) - Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT).

[0058] The antibacterial rate was measured using the national standard GB / T 31402-2015 Plastics - Test method for antibacterial properties of plastic surfaces.

[0059] The measured results are shown in the following table:

[0060]

[0061] As can be seen from the above table, the mechanical properties, antibacterial properties and antioxidant properties of the polyester material prepared in the examples of the present invention are all higher than those of the comparative examples. Therefore, the present invention has important application value in the technical field of polyester materials.

[0062] In the description of the specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A method for preparing a polyester material based on modified graphene oxide, characterized in that: The following steps are involved: The polyester chips are dried, mixed with modified graphene oxide, antibacterial agent and processing aid in a mixer, added into a twin-screw extruder, melt-blended and extruded to obtain a polyester material based on modified graphene oxide.

2. The method for preparing a polyester material based on modified graphene oxide according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 125-155 parts of polyester chips, 18-34 parts of modified graphene oxide, 7-15 parts of antibacterial agents, and 5-12 parts of processing aids.

3. The method for preparing a polyester material based on modified graphene oxide according to claim 1, characterized in that: The antibacterial agent is a quaternary ammonium salt antibacterial agent.

4. The method for preparing a polyester material based on modified graphene oxide according to claim 1, characterized in that: The processing aid is one of zinc stearate, calcium stearate and paraffin.

5. The method for preparing a polyester material based on modified graphene oxide according to claim 1, characterized in that: The modified graphene oxide is prepared by the following steps: A1. Graphene oxide and deionized water were mixed, ultrasonically dispersed, and then silane coupling agent KH-550 was added. The mixture was condensed and refluxed at 70° C. for 8 h, filtered, washed, and dried to obtain silane-modified graphene oxide. A2. Pentaerythritol, triethylamine and tetrahydrofuran were added into a three-necked flask, and phosphorus trichloride was slowly added dropwise under stirring, and the temperature was controlled not to exceed 30°C. After the addition was completed, the temperature was raised to 55°C, and the reaction was refluxed for 6 hours. After the reaction was completed, the reaction was distilled to obtain intermediate product 1; A3, add intermediate product 1, triethylamine and tetrahydrofuran into a three-necked flask, stir evenly, then add stearyl alcohol, and gradually increase the temperature until the temperature reaches 70°C, keep the temperature for 9 hours, and after the reaction is completed, distill under reduced pressure, purify by column chromatography, and rotary evaporate to obtain intermediate product 2; A4. Mix the silane-modified graphene oxide with N,N-dimethylformamide, and after ultrasonic treatment, add the intermediate product 2 and triethylamine in sequence, use a stirrer to stir and mix evenly, maintain the reaction temperature at 75°C, and keep the reaction warm for 10 hours. After the reaction is completed, vacuum distillation, washing, and freeze-drying are performed to obtain modified graphene oxide.

6. The method for preparing a polyester material based on modified graphene oxide according to claim 5, characterized in that: In step A1, the ratio of graphene oxide, deionized water, and silane coupling agent KH-550 is 1 g:100 mL:7.3 g.

7. The method for preparing a polyester material based on modified graphene oxide according to claim 5, characterized in that: In step A2, the ratio of pentaerythritol, triethylamine, tetrahydrofuran and phosphorus trichloride is 13.6 g:15 mL:100 mL:28.7 g.

8. The method for preparing a polyester material based on modified graphene oxide according to claim 5, characterized in that: In step A3, the ratio of the amount of intermediate product 1, triethylamine, tetrahydrofuran and stearyl alcohol is 27.2 g:15 mL:150 mL:26.9 g.

9. The method for preparing a polyester material based on modified graphene oxide according to claim 5, characterized in that: In step A4, the ratio of the amount of silane-modified graphene oxide, N,N-dimethylformamide, intermediate 2, and triethylamine is 1 g:100 mL:12.1 g:10 mL.

10. A polyester material based on modified graphene oxide, characterized in that: Prepared according to the method according to any one of claims 1 to 9.

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