Perfluorinated-compound-free polyether-ether-ketone water-based non-stick coating and preparation method thereof

Abstract

The invention relates to the technical field of polyether-ether-ketone polymer materials, in particular to perfluorinated-compound-free polyether-ether-ketone water-based non-stick paint and a preparation method thereof. The coating takes water as a continuous phase and contains polyether-ether-ketone ultrafine powder, and the polyether-ether-ketone ultrafine powder is prepared into the coating under the assistance of a dispersion stabilizing aid; d50 of the polyether-ether-ketone ultrafine powder is less than 15 microns, and D97 of the polyether-ether-ketone ultrafine powder is less than 30 microns; the solid content of polyether-ether-ketone in the coating is 10-45% by weight. The coating has the advantages of inherent non-stickiness, no perfluorinated compound (no PFAS) and improvement of the non-stickiness through control of a coating film forming process.

Description

Technical Field

[0001] The present invention relates to the technical field of polyetheretherketone polymer materials, and particularly relates to a perfluorinated compound-free polyetheretherketone water-based non-stick coating and a preparation method thereof. Background Art

[0002] Polymer non-stick coatings generally use polytetrafluoroethylene (PTFE) and its copolymer-modified materials as the non-stick system, and also often use engineering plastics as the film-forming resin. Polytetrafluoroethylene-based materials have stable properties and are safe for food contact, and are relatively ideal non-stick coatings, including coatings for cookware used for many years. However, in terms of molecular structure, polytetrafluoroethylene belongs to perfluoroalkyl substances (PFAS), that is, all atoms connected to carbon atoms in the molecule are fluorine atoms. In recent years, some small-molecule perfluoroalkyl (PFAS) compounds (such as perfluorooctanoic acid and perfluorooctanoate, Perfluorooctanoic acid or PFOA, and perfluorooctanesulfonic acid, Perfluorooctanesulfonic acid or PFOS) have been shown to be harmful to the human body, which has attracted people's attention and concern about fluorine compounds. Environmental protection and food safety agencies in the European Union and some regions have extended the control of perfluorinated compounds not only to small-molecule polyfluoroalkyl compounds (also simply referred to as PFAS, that is, molecules in which carbon atoms are connected to multiple fluorine atoms at the same time), but also to fluorine-containing high-molecular compounds such as polytetrafluoroethylene. Although there is no direct evidence that fluoroplastic high-molecular materials such as PTFE will cause greater harm to the human body than other high-molecular and coating materials after contacting food within the normal use range, the PFAS structure of fluoroplastic high-molecular materials makes them objects of concern or control. See Figures II and III for the structural schematic diagrams of perfluorinated compounds and polyfluorinated compounds.

[0003]

[0004] The design and development of perfluorinated and polyfluorinated compound-free high-molecular coatings have practical significance in industries such as cookware to address the doubts and possible controls regarding PFAS-related compounds. Among many engineering plastics, there are few materials with excellent comprehensive properties such as heat resistance, hydrolysis resistance, and wear resistance, and those with non-stick properties are even rarer. Polyetheretherketone is the most outstanding in terms of heat resistance and hydrolysis resistance among high-molecular materials, and will not release toxic substances or pose health risks to personnel during normal use. Although most polyetheretherketone polymers contain trace amounts of fluorine, which is derived from fluorine-containing monomers (such as 4,4-difluorobenzophenone) used in molecular chain segments and end groups, only one fluorine atom is contained in the carbon atoms of the end-group benzene ring, as shown in the structural schematic formula IV. Obviously, the carbon atoms of the end group are not connected to multiple fluorine atoms, and the molecule does not contain a perfluoro structure. Therefore, polyetheretherketone (PEEK) is a non-PFAS compound.

[0005]

[0006] The single fluorine atom connected to the carbon atom of the benzene ring at the end of the molecular chain endows polyetheretherketone with high thermal stability and hydrolysis stability, and also increases the flame retardancy of the material (including self-extinguishing, smokeless or low-smoke) and comprehensive safety performance. The PEEK with the same structure has been proven to be non-toxic and harmless to the human body and highly safe in the applications in the food and medical fields. PEEK is widely praised as a medical material due to its sterility and biocompatibility, and can be directly implanted into the human body (such as joints, teeth, spine, skull) without obvious immune and adverse reactions.

[0007] Engineering plastics generally contain polar groups and do not have good non-stick properties by themselves. Usually, low surface energy additives (such as PTFE polymers or PFAS low molecular compounds) need to be introduced to achieve non-stick properties. The applications of polyetheretherketone in self-lubricating and wear-resistant engineering materials and low surface energy coatings also often need to be achieved by adding external additives. The present invention attempts to establish a certain degree of inherent non-stickiness in the synthesis of polyetheretherketone coating resin, without adding any non-stick additives, and to prepare a polyetheretherketone coating with non-stickiness, without PFAS, and with water as the continuous phase by controlling the coating film forming process.

[0008] Traditional PTFE coatings face the risks of being prohibited by regulations in regions such as the European Union due to the PFAS structure and being questioned by the public, while existing PFAS-free high molecular coatings are difficult to have both high temperature resistance, non-stickiness and safety. Summary of the Invention

[0009] The purpose of the present invention is to provide a polyetheretherketone water-based non-stick coating without perfluorinated compounds, which has the advantages of inherent non-stickiness, without perfluorinated compounds (without PFAS), and improving non-stickiness by controlling the coating film forming process.

[0010] The technical solution adopted by the present invention to solve its technical problems is:

[0011] A polyetheretherketone water-based non-stick coating without perfluorinated compounds, the coating uses water as the continuous phase and contains polyetheretherketone ultrafine powder, and the polyetheretherketone ultrafine powder is prepared into a coating with the assistance of a dispersion stabilizing aid; the D50 of the polyetheretherketone ultrafine powder is less than 15 μm, and the D97 is less than 30 μm;

[0012] The solid content of polyetheretherketone in the coating is 10-45% by weight percentage, and the polyetheretherketone has the structure shown in Structural Formula I:

[0013]

[0014] The fluorine end group is connected to the terminal benzene ring of the molecular chain in the form of a monofluoro end group and a carbon-fluorine (C-F) single bond, without a perfluoro or polyfluoro structure (where all or multiple fluorine atoms are connected to one carbon atom); the fluorine end group content of the polyether ether ketone is greater than 1500 ppm, and the melt flow rate is greater than 100 cm 3 / 10 min (380 °C, 5 kg).

[0015] The polyether ether ketone for the non-perfluoro compound coating described in the present invention does not belong to a perfluoro or polyfluoro compound (a non-PFAS compound).

[0016] Maintain a relatively high level of the fluorine end group content in Polymer Structural Formula I, preferably greater than 1500 ppm, so as to make the polymer have a relatively low molecular weight (n < 90 in Structural Formula I), which is beneficial for the coating to have a low surface energy and good non-stickiness after film formation.

[0017] For the water-based non-stick coating of polyether ether ketone without perfluoro compounds described in the present invention, controlling the film-forming temperature and conditions has an important impact on the non-stickiness of the coating; specifically, when setting the coating baking time to 10 minutes, the film-forming temperature should be higher than 400 °C, preferably higher than 405 °C, and lower than 440 °C; controlling the crystallinity of the polymer during the film-forming process will affect the initial non-stickiness of the coating: the crystallinity should be higher than 0.1, preferably higher than 0.15, but lower than 0.3.

[0018] For the water-based non-stick coating of polyether ether ketone without perfluoro compounds described in the present invention, water is used as the medium before the non-stick coating is cured, and the polyether ether ketone is stably dispersed in the coating in the form of ultrafine powder with the assistance of a small amount of dispersion stabilizers. Appropriate color pastes can be added to the coating as needed.

[0019] Preferably, the melt flow rate of the polyether ether ketone is greater than 120 cm 3 / 10 min (380 °C, 5 kg); the fluorine end group content is 1500 - 2000 ppm. A relatively high melt flow rate is beneficial for providing high fluidity, promoting film formation, and ensuring high fluorine content and high non-stickiness.

[0020] Preferably, the melt flow rate of the polyether ether ketone is 120 - 150 cm 3 / 10 min (380 °C, 5 kg).

[0021] Preferably, the particle size D97 of the polyether ether ketone ultrafine powder is < 25 μm. Compared with materials of other particle sizes, the coating prepared from the polyether ether ketone ultrafine powder with this particle size has the advantages of excellent gloss, smooth spraying, easy wetting, good leveling, and a smooth dry film appearance.

[0022] Preferably, the solid content of polyetheretherketone in the coating is 20-40% by weight. Further, the solid content of polyetheretherketone in the coating is 25-35% by weight.

[0023] Preferably, the dispersion stabilizing aid is selected from one or more of an emulsifier, a wetting agent, a leveling agent or a rheology aid, and the weight percentage is 10-15%.

[0024] Preferably, the coating comprises the following components by mass percentage: 25-35% of PEEK ultrafine powder, 3-5% of emulsifier, 1-3% of wetting agent, 3-5% of leveling agent, 5-6% of rheology aid, 0-8% of color paste, and the balance is solvent. The solvent can be a mixture of an organic solvent and water, such as isopropanol and water.

[0025] A preparation method of a polyetheretherketone aqueous non-stick coating without perfluorinated compounds, the method comprising the following steps:

[0026] (1) Making the polyetheretherketone into an ultrafine powder with D50 less than 15 μm and D97 less than 30 μm;

[0027] (2) Mixing the ultrafine powder with water and a dispersion stabilizing aid to prepare an aqueous non-stick coating with a polyetheretherketone solid content of 10-45% by weight;

[0028] (3) Coating the aqueous non-stick coating on the surface of a substrate, heating at 180 °C for 10 minutes to level and volatilize the solvent; (4) Heating the coating obtained in step (3) at 400-440 °C for 10 minutes to form a film, and then naturally cooling, controlling the crystallinity of the obtained coating to be 0.1-0.3.

[0029] Preferably, in step (4), the film-forming temperature is 405-435 °C, and the crystallinity of the obtained coating is controlled to be 0.15-0.3.

[0030] An application of the polyetheretherketone aqueous non-stick coating without perfluorinated compounds of the present invention in a non-stick coating of a cooking utensil or a small electrical appliance. The coating has the performance of the initial non-stickiness of frying eggs at level 1 and can be recycled 50 times.

[0031] Preferably, the cooking utensil or small electrical appliance is selected from a frying pan, a wok, a steamer, a milk pan, a frying pan, an air fryer, an inner pot of an electric rice cooker or a thermos cup.

[0032] In the present invention, the polyetheretherketone coating resin has a single fluorine end group in the synthesis (structural formula I), the surface energy is reduced by adjusting the molecular weight and fluorine content to establish inherent non-stickiness; no PFAS compound non-stick aid is added; the non-stickiness is further improved by controlling the coating film-forming process.

[0033] The beneficial effects of the present invention are as follows: On the premise that the polymer has no PFAS structure and no PFAS compounds are added, inherent non-stickiness is established by means of molecular design such as adjusting the molecular weight of polyether ether ketone (the number of repeating units n < 90) and the content of fluorine end groups (> 1500 ppm) during the synthesis process; through the molecular design of single fluorine end groups, combined with the synergistic regulation of the film-forming temperature (400 - 440 °C) and the crystallinity (0.15 - 0.3), the non-stickiness of the PFAS-free coating is achieved (the initial non-stickiness of frying eggs is at the first level, and it can be cycled 50 times). Description of the Drawings

[0034] Figure 1 It shows the relationship between the non-stickiness of the coating described in the present invention and different fluorine contents;

[0035] Figure 2 It shows the relationship between the non-stickiness of the coating described in the present invention and the melt flow rate;

[0036] Figure 3 It shows the relationship between the non-stickiness of the coating described in the present invention and the film-forming temperature;

[0037] Figure 4 It shows the relationship between the non-stickiness of the coating described in the present invention and the crystallinity;

[0038] Figure 5 It shows the determination of the perfluorinated / polyfluorinated compound content of the coating described in the present invention. Detailed Embodiments

[0039] The technical solutions of the present invention will be further specifically described below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any formal modification or change made to the present invention will fall within the protection scope of the present invention.

[0040] In the present invention, unless otherwise specified, all parts and percentages are in weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are conventional methods in the art unless otherwise specified.

[0041] The reagents used in the following embodiments can be purchased from conventional biochemical reagent stores without special instructions.

[0042] The PEEK ultrafine powder is of the 8900UFP model produced by Zhejiang Pengfulong Technology Co., Ltd., and other materials are conventional materials used in the coating without special requirements. The emulsifiers include ionic emulsifiers (such as long-chain alkyl sulfonates) or non-ionic emulsifiers (such as polyethylene glycol ethers); the wetting agents and leveling agents include polyether siloxanes and polyacrylate compounds; the rheology aids include carboxymethyl cellulose, sodium polyacrylate, polyethylene oxide, etc.

[0043] One of the cores of the present invention is to protect a perfluorinated compound-free polyether ether ketone water-based non-stick coating. The coating uses water as the continuous phase and contains polyether ether ketone ultrafine powder, which is stably dispersed in the coating with the assistance of a dispersion stabilizer. The D50 of the polyether ether ketone ultrafine powder is less than 15 μm, and the D97 is less than 30 μm.

[0044] The solid content of polyether ether ketone in the coating is 10-45% by weight percentage, and the polyether ether ketone has the structure shown in Structural Formula I:

[0045]

[0046] The fluorine end group is connected to the benzene ring at the molecular chain end in the form of a monofluoro end group and a carbon-fluorine (C-F) single bond, without a perfluoro or polyfluoro structure (where all or multiple fluorine atoms are connected to one carbon atom); the fluorine end group content of the polyether ether ketone is greater than 1500 ppm, and the melt flow rate is greater than 100 cm 3 / 10 min (380 °C, 5 kg).

[0047] The present invention also provides a preparation method for the perfluorinated compound-free polyether ether ketone water-based non-stick coating, which includes the following steps:

[0048] (1) Make the polyether ether ketone into ultrafine powder with D50 less than 15 μm and D97 less than 30 μm;

[0049] (2) Mix the ultrafine powder with water and a dispersion stabilizer to make a water-based non-stick coating with a polyether ether ketone solid content of 10-45% by weight percentage;

[0050] (3) Coat the water-based non-stick coating on the surface of the substrate, and heat it at 180 °C for 10 minutes to level and volatilize the solvent; (4) Heat the coating obtained in step (3) at 400-440 °C for 10 minutes to form a film, and then cool it naturally, controlling the crystallinity of the obtained coating to be 0.1-0.3.

[0051] Example: Basic formula of PEEK non-stick coating

[0052] A preparation method for a perfluorinated compound-free polyether ether ketone water-based non-stick coating, and the specific steps of the method are as follows:

[0053] (1) Make the polyether ether ketone into ultrafine powder with D50 less than 15 μm and D97 less than 30 μm;

[0054] (2) Add the deionized water, isopropanol, emulsifier, and wetting agent described in Table 1 in sequence, stir at room temperature for 5 minutes, then sprinkle and add the polyether ether ketone (PEEK) ultrafine powder in batches, stir at 300 rpm for 30 minutes, and then add the leveling agent, rheology aid, and color paste in sequence, stir at 300 rpm for 10 minutes to prepare an aqueous non-stick coating with a PEEK solid content of 30% by weight;

[0055] (3) Coat the surface of the substrate with the aqueous non-stick coating, heat at 180 °C for 10 minutes to level and volatilize the solvent; (4) Heat the coating obtained in step (3) at 400 - 440 °C for 10 minutes to form a film, and then cool naturally, controlling the crystallinity of the obtained coating to be 0.1 - 0.3.

[0056] Select PEEK ultrafine powders with different particle sizes according to the formula described in Table 1 for experiments, and the experimental schemes and test results are shown in Table 2.

[0057] Table 1: Example of PEEK non-stick coating formula

[0058] Material Name Formulation Weight Percentage Deionized Water 44 Isopropyl Alcohol 6 Emulsifier 3.5 Wetting Agent 2 PEEK Ultrafine Powder 30 Leveling Agent 4.0 Rheology Additive 5.5 Color Paste 5 Total 100

[0059] Table 2: Spraying and film-forming effects of PEEK with different fine powder particle sizes

[0060]

[0061]

[0062] According to the results in Table 2, it can be seen that by selecting PEEK ultrafine powder with a particle size D97 < 25 μm, the prepared coating has the advantages of excellent gloss, smooth spraying, easy wetting, good leveling, and a smooth dry film appearance.

[0063] Example: Compare the film-forming situations of PEEK with different melt flow rates (MFR).

[0064] Select PEEK ultrafine powders with a particle size D97 < 25 μm and different melt flow rates according to the formula in Table 1 for experiments, and the experimental schemes, film-forming effects, and test results are shown in Table 3.

[0065] Table 3: Film-forming effects of PEEK coatings with different melt flow rates

[0066]

[0067]

[0068] According to the results in Table 3, it can be seen that a resin with a melt flow rate greater than 100 cm3 / 10 min (380 °C, 5 Kg) should be selected. The melt flow rate of the polyether ether ketone is 120 - 150 cm 3 / 10 min (380 °C, 5 kg) has better product performance.

[0069] Example: Non-stick properties of PEEK coatings with different fluorine contents

[0070] Select PEEK ultrafine powder with a particle size D97 < 25 μm and a melt flow rate of 124 ± 5 cm 3 / 10 min (380 °C, 5 kg) according to the formulation in Table 1. Two groups of examples (19, 20) with fluorine contents of 1950 PPM and 1090 PPM were compared for non-stick properties.

[0071] Non-stick test method:

[0072] Pour an appropriate amount of vegetable oil into the cooking utensil and spread it evenly on the non-stick surface with a soft cloth.

[0073] Wash the cooking utensil with warm water above 60 °C and neutral detergent, then rinse it with clean water and dry it.

[0074] Place the cooking utensil on an electric furnace with a rated voltage of 220 V and an output power of 1 kW for heating.

[0075] Measure with a surface thermometer with an accuracy of not less than 2.5 grades. When the surface temperature of the inner coating reaches ~150 °C, break a fresh egg that meets the requirements of Grade 2 (weight 50 g - 60 g) specified in SB / T 10277—1997 and put it into the cooking utensil. Wait for 80 - 90 seconds until the egg white is basically solidified (during the whole cooking process, the surface temperature of the inner coating should not exceed 180 °C).

[0076] Use a plastic spatula with a blade thickness of 0.2 mm - 0.5 mm to completely take out the egg. If there is egg residue attached, gently wipe it off with a wet sponge or gauze. Repeat the above heating and cooking steps for a total of 3 tests, observe and record the results.

[0077] Conduct the national standard fried egg test according to the requirements of GB 32095-2015 to determine the non-stick grade:

[0078] 1. The egg can be taken out without damage by a plastic spatula and no residue is left, Grade I

[0079] 2. The egg cannot be taken out without damage by a plastic spatula, but the residue can be removed by gently wiping with a wet sponge or cloth, Grade II

[0080] 3. The residue cannot be removed by gently wiping with a wet sponge or cloth, Grade III

[0081] The non-stick results are shown in Figure 1。PEEK contains fluorine end groups. When the molecular weight is high, the content of fluorine end groups is low. By adjusting the molecular weight and fluorine content in the present invention, a high degree of non-stickiness is achieved. For the convenience of comparing non-stickiness, the relative value 9 is selected for Grade I non-stickiness, the relative value 6 is selected for Grade II non-stickiness, and the relative value 3 is selected for Grade III non-stickiness (the same treatment is applied hereinafter).

[0082] The PEEK polymer contains a certain amount of fluorine element. However, due to its end group monofluoro structure, the coating sample has been tested and proven to pass the perfluoro / polyfluoro (PFAS) content test (the content of PFAS compounds is lower than the reported limit value), as shown in the appendix Figure 5 。

[0083] Example: Non-stickiness of PEEK with different melt flow rates

[0084] Select PEEK ultrafine powder with a particle size D97 < 25μm and 4 different specifications of melt flow rates according to the formula in Table 1. Four groups of examples (21 - 24) are used for non-stickiness test comparison, and the results are shown in Figure 2 。The melt flow rate of the polymer reflects both the molecular size and fluidity of the polymer (the larger the melt flow rate, the better the fluidity and the smaller the molecular weight), and is also related to the fluorine content of the end groups. Experiments have found that a higher melt flow rate (lower molecular weight) is helpful for non-stickiness. To maintain non-stickiness, the melt flow rate should be selected to be greater than 100 cm 3 / 10 min (380 °C, 5 Kg).

[0085] Example: Non-stickiness test comparison at different film-forming temperatures

[0086] Select PEEK ultrafine powder with a particle size D97 < 25μm, a fluorine content of 1950 PPM, and a melt flow rate of 124 to form films at different temperatures. Table 4 lists the non-stickiness of the coatings under the film-forming temperature conditions, Figure 3 providing an intuitive relative comparison.

[0087] Table 4. Non-stickiness test comparison at different film-forming temperatures

[0088]

[0089] *The sample is heated at the film-forming temperature for 10 minutes and is pre-heated at 180 °C for 10 minutes for leveling and volatilization

[0090] From Table 4 and the appendix Figure 3 it can be seen that the film-forming temperature has an impact on non-stickiness. Both too high and too low temperatures will affect the non-stickiness of the coating surface. When setting 10 minutes as the coating baking time, the film-forming temperature should be higher than 400 °C, preferably higher than 405 °C, and lower than 440 °C.

[0091] Film formation at different temperatures will also affect the crystallinity of the PEEK resin. As shown in the appendix Figure 4Show the initial non-stickiness of the coating at different degrees of crystallinity. Experiments found that the initial non-stickiness does not necessarily increase with the increase in crystallinity. Instead, there is an opposite trend within a certain range. When the degree of crystallinity is too low, the non-stickiness also decreases. The decrease in the initial non-stickiness with too low crystallinity may be related to the increase in the friction coefficient of the polymer. However, when the degree of crystallinity reaches 0.3, the non-stickiness may decrease due to the hindrance of the mobility of the non-sticky components. In terms of only the initial non-stickiness, the degree of crystallinity should be higher than 0.1, preferably higher than 0.15, but lower than 0.3. Experiments found that the film-forming process can better control the range of crystallinity.

[0092] Example: Non-stickiness cycle test

[0093] Select PEEK ultrafine powder with a particle size D97 = 24 μm, a fluorine content of 1950 PPM, and a melt flow rate of 124. Prepare the coating according to the formula in Table 1, cure it into a film at 415 °C, and test the number of cycles to reach non-stickiness level 1 (Example 26).

[0094] Non-stickiness cycle test method: Pour an appropriate amount of vegetable oil into the cooking utensil, and evenly smear the non-stick surface with a soft cloth. Wash the cooking utensil with warm water above 60 °C plus a neutral detergent, then rinse it with clean water and dry it. Place the cooking utensil on an electric furnace with a rated voltage of 220 V and an output power of 1 kW for heating. Use a surface thermometer with an accuracy of not less than 2.5 levels to measure. When the surface temperature of the inner coating reaches ~150 °C, break a fresh egg that meets the requirements of grade 2 (weight between 50 g and 60 g) specified in SB / T 10277—1997 and put it into the cooking utensil. Wait for 80 - 90 seconds until the egg white is basically solidified (during the whole cooking process, the surface temperature of the inner coating should not exceed 180 °C). Use a plastic spatula with a blade thickness of 0.2 mm - 0.5 mm to completely take out the egg. If there is egg residue attached, gently wipe it off with a wet sponge or gauze. Repeat the above heating and cooking steps, stop the test when the non-stickiness reaches level II, and observe and record the number of times the non-stickiness passes as level I.

[0095] Conduct the national standard fried egg test according to the requirements of GB 32095-2015 to determine the non-stickiness grade:

[0096] 1. Grade I: The egg can be taken out without damage by a plastic spatula and no residue is left.

[0097] 2. Grade II: The egg cannot be taken out without damage by a plastic spatula, but the residue can be removed by gently wiping with a wet sponge or cloth. 3. Grade III: The residue cannot be removed by gently wiping with a wet sponge or cloth.

[0098] Conduct more than 5 small-scale experiments and non-stickiness tests, and record the number of cycles of non-stickiness level I. The results show that the number of cycles > 50 times, indicating good non-stickiness.

[0099] Through molecular design such as polyether ether ketone mono-fluoro end groups and film-forming process control, the present invention achieves good non-stick properties of the PFAS-free coating. The initial non-stick property for frying eggs is Grade I, and it can reach 50 times of repeated cycles.

Claims

1. A perfluorinated compound-free polyetheretherketone water-based non-stick coating, characterized in that: The coating uses water as the continuous phase and contains ultrafine polyetheretherketone powder. The ultrafine polyetheretherketone powder is prepared into a coating with the assistance of a dispersion stabilizer. The D50 of the ultrafine polyetheretherketone powder is less than 15 μm, and the D97 is less than 30 μm. The solid content of polyetheretherketone in the coating is 10 - 45% by weight, and the polyetheretherketone has the structure shown in Structural Formula I: The fluorine end group is connected to the terminal benzene ring of the molecular chain in the form of a single fluorine end group and a carbon-fluorine (C-F) single bond, without a perfluoro or polyfluoro structure (where all or multiple fluorine atoms are connected to one carbon atom) and without PFAS substances. The fluorine end group content of the polyether ether ketone is greater than 1500 ppm, and the melt flow rate is greater than 100 cm 3 / 10 min (380 °C, 5 kg).

2. The perfluorocompound-free polyetheretherketone water-based non-stick coating according to claim 1, wherein: The melt flow rate of the polyetheretherketone is greater than 120 cm 3 / 10 min (at 380 °C, 5 kg); the fluorine end group content is 1500 - 2000 ppm.

3. The perfluorocompound-free polyetheretherketone water-based non-stick coating according to claim 1, characterized in that: The melt flow rate of the polyether ether ketone is 120-150 cm 3 / 10 min (380 °C, 5 kg).

4. The perfluorocompound-free polyetheretherketone water-based non-stick coating according to claim 1, characterized in that: The solid content of polyetheretherketone in the coating is 20 - 40% by weight.

5. The perfluorocompound-free polyetheretherketone water-based non-stick coating according to claim 1, characterized in that: The solid content of polyetheretherketone in the coating is 25 - 35% by weight.

6. The perfluorocompound-free polyetheretherketone water-based non-stick coating according to claim 1, characterized in that: The dispersion stabilizer is selected from one or more of emulsifiers, wetting agents, leveling agents, or rheological aids, and the weight percentage is 10 - 15%.

7. A preparation method of a perfluorinated compound-free polyetheretherketone water-based non-stick coating, characterized in that, This method includes the following steps: (1) Prepare the polyetheretherketone into ultrafine powder with D50 less than 15 μm and D97 less than 30 μm. (2) Mix the ultrafine powder with water and a dispersion stabilizer to prepare an aqueous non-stick coating with a polyetheretherketone solid content of 10 - 45% by weight. (3) Coat the aqueous non-stick coating on the surface of the substrate, heat it at 180 °C for 10 minutes to level and volatilize the solvent. (4) Heat the coating obtained in step (3) at 400 - 440 °C for 10 minutes to form a film, and then cool it naturally, controlling the crystallinity of the obtained coating to be 0.1 - 0.

3.

8. The preparation method according to claim 7, characterized in that: In step (4), the film-forming temperature is 405 - 435 °C, and the crystallinity of the obtained coating is controlled to be 0.15 - 0.

3.

9. Application of the polyetheretherketone aqueous non-stick coating without perfluorinated compounds according to any one of claims 1 - 6 in non-stick coatings for cookware or small appliances.

10. The application according to claim 9, characterized in that: The cookware or small appliances are selected from frying pans, woks, steamers, milk pans, frying pans, air fryers, inner pots of rice cookers, or vacuum flasks.

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