A modified graphene oxide-based polyester material and a method for preparing the same

Abstract

This invention discloses a polyester material based on modified graphene oxide and its preparation method, belonging to the field of polyester material technology. It comprises the following raw materials in parts by weight: 125-155 parts polyester chips, 18-34 parts modified graphene oxide, 7-15 parts antibacterial agent, and 5-12 parts processing aids. The modified graphene oxide molecules are linked with hydrophobic modifying groups, making it hydrophobic, improving its compatibility with polyester, and facilitating the expression of its properties. This significantly enhances the mechanical properties and antibacterial properties of the polyester material. Furthermore, it synergistically enhances the antibacterial properties of the polyester with the quaternary ammonium salt antibacterial agent in the raw materials. In addition, the modified graphene oxide molecules also contain phosphite groups, enhancing the antioxidant properties of the polyester material. In summary, the polyester material obtained by this invention possesses excellent mechanical properties, antibacterial properties, and antioxidant properties, and has significant application value in the field of polyester material technology.

Description

Technical Field

[0001] This invention belongs to the field of polyester material technology, specifically, it relates to a polyester material based on modified graphene oxide and its preparation method. Background Technology

[0002] Graphene is a two-dimensional crystal composed of carbon atoms, only one atom thick. It is the thinnest material in the world and possesses excellent electrical, thermal, and mechanical properties. As the thinnest, strongest, and most conductive and thermally conductive nanomaterial discovered to date, it has potential applications in aerospace, military, solar cells, flexible displays, sensors, adsorption, and many other fields. Scientists have even predicted that graphene will "completely change the 21st century" and is very likely to trigger a disruptive new technology and industrial revolution sweeping the globe.

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

[0004] Polyester is a general term for polymers obtained by the condensation polymerization of polyols and polyacids. It mainly refers to polyethylene terephthalate (PET), but also conventionally includes linear thermoplastic resins such as polybutylene terephthalate (PBT) and polyarylates. Polyester materials possess many excellent properties, such as high toughness and strength, making them a class of high-performance engineering plastics. Due to their outstanding properties, they are widely used in packaging, electronics, medical and health, construction, and automotive industries. However, with the continuous improvement of people's demands, the requirements for polyester are also increasing. Therefore, some research has used graphene oxide as a raw material to add to polyester materials to improve their performance. However, graphene oxide is an inorganic non-metallic material with poor compatibility with organic polyester materials, and it is prone to agglomeration in the material, seriously affecting the performance of the polyester material. Therefore, there is an urgent need to invent a modified graphene oxide with good compatibility with polyester materials to meet the higher demands of the polyester material technology field. Summary of the Invention

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

[0006] The objective of this invention can be achieved through the following technical solutions:

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

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

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

[0010] Furthermore, the drying conditions are drying in an oven at 70-80℃ for 12-24 hours.

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

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

[0013] Adding quaternary ammonium salt antibacterial agents to the raw materials allows the positively charged quaternary ammonium salt ions to generate strong electrostatic interactions with the negatively charged bacteria, resulting in a strong adsorption effect on the bacteria and significantly enhancing the antibacterial properties of the material. In addition, the added processing aids can act as a lubricant, making the raw materials mix more evenly.

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

[0015] A1. Mix graphene oxide and deionized water, disperse by ultrasonication, then add silane coupling agent KH-550, reflux at 70°C for 8 hours, filter, wash the filter residue several times with anhydrous ethanol and deionized water, and then dry it in an oven to obtain silane-modified graphene oxide.

[0016] Silane-modified graphene oxide was obtained by hydrophobic modification of graphene oxide using silane coupling agent KH-550.

[0017] A2. Add pentaerythritol, triethylamine (catalyst) and tetrahydrofuran to a three-necked flask equipped with a thermometer, stirrer and condenser. While stirring, slowly add phosphorus trichloride dropwise, controlling the temperature not to exceed 30°C. After the addition is complete, raise the temperature to 55°C and reflux for 6 hours. When the reaction is complete, remove the solvent tetrahydrofuran and excess phosphorus trichloride by distillation to obtain intermediate product 1.

[0018] Catalyzed by triethylamine, 1 mol of pentaerythritol reacts with 2 mol of phosphorus trichloride, with a slight excess of phosphorus trichloride, to give intermediate product 1; the specific reaction is shown below:

[0019]

[0020] A3. Add intermediate product 1, triethylamine and tetrahydrofuran to a three-necked flask equipped with a thermometer and a stirrer. After stirring evenly, add stearyl alcohol and gradually raise the temperature until it reaches 70°C. Keep the temperature for 9 hours. After the reaction is complete, distill under reduced pressure, purify by column chromatography, and remove the eluent by rotary evaporation to obtain intermediate product 2.

[0021] Intermediate product 1 reacts with stearyl alcohol to form S N The nucleophilic substitution reaction was carried out by controlling the molar ratio of the two products to be close to 1:1, and by using a slight excess of intermediate 1, so that only 1 mol of stearyl alcohol participated in the reaction, yielding intermediate 2. The specific reaction process is as follows:

[0022]

[0023] A4. Silane-modified graphene oxide was mixed with N,N-dimethylformamide and ultrasonically treated for 30 min. Then, intermediate product 2 and triethylamine were added sequentially. The mixture was stirred and mixed evenly using a stirrer. The reaction temperature was maintained at 75℃ and the reaction was kept at this temperature for 10 h. After the reaction was completed, the modified graphene oxide was obtained by vacuum distillation, washing, and freeze drying.

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

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

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

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

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

[0029] Graphene oxide possesses excellent antibacterial and mechanical properties. Firstly, graphene oxide is hydrophobically modified using the silane coupling agent KH-550, increasing its compatibility with the polyester matrix. Secondly, intermediate product 2 is prepared through a reaction. Intermediate product 2 contains a long carbon chain and exhibits excellent hydrophobic properties. This intermediate product 2 is then used to further hydrophobically modify graphene oxide, further enhancing its hydrophobicity. This allows graphene oxide to disperse uniformly in the polyester matrix, reducing agglomeration and fully utilizing its properties, significantly improving the antibacterial and mechanical properties of the matrix. Furthermore, the modified graphene oxide molecule contains phosphite functional groups. Phosphite, as an antioxidant, can decompose the hydroperoxides generated in the polyester matrix due to oxidative aging, rendering them inactive substances. This terminates or delays the oxidative degradation of the polyester, improving the antioxidant properties of the matrix.

[0030] The beneficial effects of this invention are:

[0031] This 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 molecules are linked with hydrophobic modifying groups, making it hydrophobic, improving its compatibility with polyester, and allowing its performance to be more easily realized. This significantly enhances the mechanical properties and antibacterial properties of the polyester material. Furthermore, it can synergistically interact with the quaternary ammonium salt antibacterial agents in the raw materials, further enhancing the antibacterial properties of the polyester. In addition, the modified graphene oxide molecules also contain phosphite groups, which enhance the antioxidant properties of the polyester material. In summary, the polyester material prepared by this invention has excellent mechanical properties, antibacterial properties, and antioxidant properties, and has significant application value in the field of polyester material technology. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Preparation of modified graphene oxide:

[0035] A1. Mix 1g of graphene oxide and 100mL of deionized water, disperse by ultrasonication, then add 7.3g of silane coupling agent KH-550, reflux at 70℃ for 8h, filter, wash the filter residue several times with anhydrous ethanol and deionized water, and then dry it in an oven to obtain silane-modified graphene oxide.

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

[0037] A3. Add 27.2g of intermediate product 1, 15mL of triethylamine and 150mL of tetrahydrofuran to a three-necked flask equipped with a thermometer and a stirrer. After stirring evenly, add 26.9g of stearyl alcohol and gradually raise the temperature until it reaches 70℃. Keep the temperature for 9 hours. After the reaction is complete, distill under reduced pressure, purify by column chromatography, and remove the eluent by rotary evaporation to obtain intermediate product 2.

[0038] A4. Mix 1g of silane-modified graphene oxide with 100mL of N,N-dimethylformamide, sonicate for 30min, then add 12.1g of intermediate product 2 and 10mL of triethylamine in sequence. Stir and mix evenly using a stirrer, maintain the reaction temperature at 75℃ and keep the reaction at this temperature for 10h. After the reaction is complete, distill under reduced pressure, wash, and freeze dry to obtain modified graphene oxide.

[0039] Example 2

[0040] Preparation of modified graphene oxide:

[0041] A1. Mix 2g of graphene oxide and 200mL of deionized water, disperse by ultrasonication, then add 14.6g of silane coupling agent KH-550, reflux at 70℃ for 8h, filter, wash the filter residue several times with anhydrous ethanol and deionized water, and then dry it in an oven to obtain silane-modified graphene oxide.

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

[0043] A3. Add 54.4g of intermediate product 1, 30mL of triethylamine and 300mL of tetrahydrofuran to a three-necked flask equipped with a thermometer and a stirrer. After stirring evenly, add 53.8g of stearyl alcohol and gradually raise the temperature until it reaches 70℃. Keep the temperature for 9 hours. After the reaction is complete, distill under reduced pressure, purify by column chromatography, and remove the eluent by rotary evaporation to obtain intermediate product 2.

[0044] A4. Mix 2g of silane-modified graphene oxide with 200mL of N,N-dimethylformamide, sonicate for 30min, then add 24.2g of intermediate product 2 and 20mL of triethylamine in sequence. Stir and mix evenly using a stirrer, maintain the reaction temperature at 75℃ and keep the reaction at this temperature for 10h. After the reaction is complete, distill under reduced pressure, wash, and freeze dry to obtain modified graphene oxide.

[0045] Example 3

[0046] 125g of polyester chips were dried in an oven at 70°C for 12 hours. After drying, they were mixed with 18g of modified graphene oxide prepared in Example 1, 7g of quaternary ammonium salt antibacterial agent (hexadecyltrimethylammonium bromide) and 5g of zinc stearate in a mixer. After being mixed evenly, the mixture was added to a twin-screw extruder and melt-blended to obtain a polyester material based on modified graphene oxide.

[0047] Example 4

[0048] 140g of polyester chips were dried in an oven at 80℃ for 24h. After drying, they were mixed with 26g of modified graphene oxide prepared in Example 2, 11g of quaternary ammonium salt antibacterial agent (hexadecyltrimethylammonium bromide) and 8g of calcium stearate in a mixer. After being mixed evenly, the mixture was added to a twin-screw extruder and melt-blended and extruded to obtain a polyester material based on modified graphene oxide.

[0049] Example 5

[0050] 155g of polyester chips were dried in an oven at 80℃ for 24 hours. After drying, they were mixed with 34g of modified graphene oxide prepared in Example 2, 15g of quaternary ammonium salt antibacterial agent (hexadecyltrimethylammonium bromide) and 12g of paraffin in a mixer. After being mixed evenly, the mixture was added to a twin-screw extruder and melt-blended and extruded to obtain a polyester material based on modified graphene oxide.

[0051] Comparative Example 1

[0052] The polyester material was prepared by replacing the modified graphene oxide in Example 5 with the same mass of unmodified ordinary graphene oxide, and the remaining steps were the same as in Example 5.

[0053] Comparative Example 2

[0054] Use commercially available polyester masterbatch.

[0055] Examples 3, 4, and 5, and Comparative Examples 1 and 2, were fabricated into corresponding shapes according to different testing standards, and the following performance tests were conducted:

[0056] Tensile strength was determined according to the national standard GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets";

[0057] The induction time of the sample was determined according to the national standard GB / T 19466.6-2009 "Differential scanning calorimetry (DSC) for plastics - Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)".

[0058] The antibacterial rate was determined using the national standard GB / T31402-2015 "Test Method for Antibacterial Properties of Plastic Surfaces".

[0059] The measurement results are shown in the table below:

[0060]

[0061] As can be seen from the table above, the polyester material prepared by the embodiments of the present invention has higher mechanical properties, antibacterial properties and antioxidant properties than the comparative example. Therefore, the present invention has important application value in the field of polyester material technology.

[0062] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which 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, Includes the following steps: The polyester chips are dried, and then mixed with modified graphene oxide, antibacterial agent and processing aid in a mixer. The mixture is then added to a twin-screw extruder for melt blending and extrusion to obtain a polyester material based on modified graphene oxide. The modified graphene oxide is prepared through the following steps: A1. Mix graphene oxide and deionized water, disperse by ultrasonication, add silane coupling agent KH-550, reflux at 70°C for 8 hours, filter, wash, and dry to obtain silane-modified graphene oxide. A2. Add pentaerythritol, triethylamine and tetrahydrofuran to a three-necked flask. Add phosphorus trichloride dropwise while stirring, keeping the temperature below 30°C. After the addition is complete, raise the temperature to 55°C and reflux for 6 hours. Once the reaction is complete, distill to obtain intermediate product 1. A3. Add intermediate product 1, triethylamine and tetrahydrofuran to a three-necked flask, stir well, then add stearyl alcohol, and gradually raise the temperature until it reaches 70°C. Keep the temperature for 9 hours to complete the reaction. Distill under reduced pressure, purify by column chromatography, and rotary evaporate to obtain intermediate product 2. A4. Silane-modified graphene oxide was mixed with N,N-dimethylformamide and ultrasonically treated. Then, intermediate product 2 and triethylamine were added sequentially. The mixture was stirred and mixed evenly using a stirrer. The reaction temperature was maintained at 75℃ and the reaction was kept at this temperature for 10 hours. After the reaction was completed, the mixture was distilled under reduced pressure, washed, and freeze-dried to obtain 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 as follows by weight: 125-155 parts polyester chips, 18-34 parts modified graphene oxide, 7-15 parts antibacterial agent, and 5-12 parts 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 wax.

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

6. The method for preparing a polyester material based on modified graphene oxide according to claim 1, characterized in that, In step A2, the ratio of pentaerythritol, triethylamine, tetrahydrofuran, and phosphorus trichloride is 13.6g:15mL:100mL:28.7g.

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

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

9. A polyester material based on modified graphene oxide, characterized in that, Prepared according to the method according to any one of claims 1-8.

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