Wear-resistant and aging-resistant ship functional film as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of functional film materials, and relates to a wear-resistant and aging-resistant ship functional film as well as a preparation method and application thereof. The invention aims to solve the problems of single function and poor marine environment adaptability of the existing ship functional film. The preparation method comprises the following steps: carrying out surface modification on nano-zinc oxide to prepare modified nano-particles, and carrying out in-situ emulsion polymerization reaction on the modified nano-particles and tetrafluoroethylene to prepare ZnONPs / PTFE composite powder; preparing a polyimide film through processes such as low-temperature polymerization reaction, and then performing annealing treatment and surface activation to obtain a polyimide functional layer; and coating the ZnONPs / PTFE composite powder on the surface of the polyimide functional layer through electrostatic spraying, heating and pressing to obtain the polytetrafluoroethylene functional layer, and finally obtaining the wear-resistant and aging-resistant ship functional film. The wear-resistant and aging-resistant ship functional film provided by the invention has high corrosion resistance and mechanical strength in a marine environment, and has a good application prospect in the field of ships.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional film materials, and relates to a wear-resistant and aging-resistant ship functional film, a preparation method thereof and an application thereof. Background Art

[0002] As an important place for the daily life and work of crew members, the comfort and safety of the internal environment of ship cabins are directly related to the work efficiency and physical and mental health of crew members. With the development of shipbuilding and navigation technologies, the materials inside ship cabins have gradually attracted the attention of the shipping industry. In the early days, the interior decoration materials of ship cabins mainly consisted of traditional coatings, wood materials and metal materials. However, in the complex and changeable marine environment of ships, these materials gradually showed some significant problems, such as poor weather resistance, high maintenance costs and single functions.

[0003] Currently, in the field of interior decoration materials for ship cabins, functional films have gradually gained people's favor. Functional films can achieve functions such as humidity adjustment, antibacterial and antifungal in the cabin, improve the comfort and health of the cabin, and at the same time, as a protective layer, improve the wear resistance and aging resistance of the cabin body. However, at present, the functions of the functional films used for the interior decoration of ship cabins are still relatively single, and their adaptability to the marine environment is not good, and they cannot maintain their wear resistance and aging resistance well.

[0004] At present, the single function of existing ship functional films and poor adaptability to the marine environment are still important problems faced by the industry.

[0005] Therefore, a wear-resistant and aging-resistant ship functional film, a preparation method thereof and an application thereof are proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a wear-resistant and aging-resistant ship functional film, a preparation method thereof and an application thereof. The present invention prepares modified nanoparticles by surface modification of nano-zinc oxide, and prepares ZnONPs / PTFE composite powder through in-situ emulsion polymerization reaction with tetrafluoroethylene; prepares a polyimide film through processes such as low-temperature polymerization reaction, and then conducts annealing treatment and surface activation to obtain a polyimide functional layer; sprays the ZnONPs / PTFE composite powder on the surface of the polyimide functional layer by electrostatic spraying, and conducts heating and pressing to obtain a polytetrafluoroethylene functional layer, and finally obtains a wear-resistant and aging-resistant ship functional film.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A preparation method of a wear-resistant and aging-resistant ship functional film, comprising the following steps:

[0009] Unless otherwise specified, all parts in the present invention are parts by mass.

[0010] Disperse 110 parts of nano-zinc oxide in 300 parts of absolute ethanol at an ultrasonic frequency of 30 kHz to obtain a zinc oxide dispersion; keep stirring the zinc oxide dispersion at 35 °C at a rotation speed of 300 rpm, slowly add 10 - 15 parts of perfluorohexylethyl phosphate, and after stirring for 4 - 6 hours, centrifuge to obtain a solid product, and obtain modified nanoparticles after washing and drying.

[0011] Among them, the particle size of the nano-zinc oxide is 80 - 120 nm.

[0012] Carry out an in-situ emulsion polymerization reaction on the modified nanoparticles and tetrafluoroethylene to obtain ZnONPs / PTFE composite powder;

[0013] Carry out a low-temperature polymerization reaction on purified pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, hexafluoroisopropyl diamine and m-phenylenediamine under nitrogen protection to obtain a polyamic acid solution.

[0014] Among them, the addition amount of pyromellitic dianhydride is 22.0 parts, the addition amount of biphenyltetracarboxylic dianhydride is 29.5 parts, the addition amount of hexafluoroisopropyl diamine is 44.5 parts, and the addition amount of [the unnamed substance] is 11.0 parts.

[0015] Filter the polyamic acid solution with a 0.45 μm filter membrane and then uniformly coat it on a flat glass substrate, heat it to 45 °C at a heating rate of 1 °C / min and then keep it warm and dry for 2 hours to obtain a polyamic acid film.

[0016] Put the polyamic acid film into a vacuum oven, keep the operating pressure at 0.2 atm, heat it to 80 °C at a heating rate of 5 °C / min and then carry out heat treatment for 30 min, then heat it to 150 °C at a heating rate of 2 °C / min and carry out heat treatment for 60 min, reduce the operating pressure to 0.1 atm, heat it to 320 °C at a heating rate of 2 °C / min and carry out heat treatment for 90 min, cool it to 25 °C at a cooling rate of 5 °C / min, and then restore to 1 atm pressure to obtain a polyimide film.

[0017] Carry out annealing treatment and surface activation on the polyimide film to obtain a polyimide functional layer.

[0018] Coat the ZnONPs / PTFE composite powder on the surface of the polyimide functional layer by electrostatic spraying.

[0019] Place the polyimide functional layer coated with the ZnONPs / PTFE composite powder in a mold, heat it at 330 °C for 30 min, and press the polyimide functional layer at a pressure of 1 MPa. After the treatment is completed, heat it to 510 °C in an argon atmosphere and cool it to 25 °C at a cooling rate of 5 °C / min to prepare a polytetrafluoroethylene functional layer on the surface of the polyimide functional layer.

[0020] The polytetrafluoroethylene functional layer and the polyimide functional layer together form a wear-resistant and aging-resistant ship functional film.

[0021] Preferably, the process of the emulsion polymerization reaction is as follows: 100 parts of modified nanoparticles are dispersed in 400 parts of the reaction emulsion. Tetrafluoroethylene monomer is introduced under a stirring speed of 250 rpm. After the temperature is raised to 75 - 80 °C, ammonium persulfate is added under an operating pressure of 2.0 MPa. After reacting for 6 - 8 hours, the introduction of tetrafluoroethylene monomer is stopped, and the emulsion is separated, washed, and dried to obtain ZnONPs / PTFE composite powder; the reaction emulsion includes: deionized water, methyl formate, acetone, perfluoropropyl vinyl ether, and ammonium perfluorooctanoate; the addition amount of ammonium persulfate is 3 - 5 ppm relative to deionized water; in the reaction emulsion, the mass ratio of deionized water, methyl formate, acetone, perfluoropropyl vinyl ether, and ammonium perfluorooctanoate is 92:2:1:3:2.

[0022] Preferably, the process of the low-temperature polymerization reaction is as follows: Purified hexafluoroisopropyl diamine and m-phenylenediamine are dissolved in N-methylpyrrolidone under nitrogen protection. The reaction temperature is controlled at 0 - 10 °C. Pyromellitic dianhydride and biphenyltetracarboxylic dianhydride are slowly added to the reaction system under a stirring speed of 800 - 1200 rpm. The solid content of the solution is controlled at 20 - 25 wt%, and the reaction continues for 12 - 15 hours to obtain a polyamic acid solution.

[0023] Preferably, the process of the annealing treatment is as follows: The polyimide film is heated to 200 °C at a heating rate of 5 °C / min and then heat-treated for 400 min, and then cooled to 25 °C at a cooling rate of 2 - 3 °C / min to obtain an annealed polyimide film.

[0024] Preferably, the process of the surface activation is as follows: The annealed polyimide film is soaked in a 2 wt% sodium hydroxide aqueous solution for 10 min and then rinsed with deionized water. After drying, ammonia plasma treatment is carried out at an operating temperature of 350 °C, where the radio frequency power is 200 W, the radio frequency frequency is 13.56 MHz, the ammonia flow rate is 40 - 50 sccm, the operating pressure is 10 Pa, and after treatment for 5 min, a polyimide functional layer is obtained.

[0025] Preferably, the operating parameters of the electrostatic spraying are: the voltage is 50 kV, the spraying air pressure is 0.2 - 0.4 MPa, the spraying distance is 20 cm, and the overlapping rate is 30%.

[0026] A wear-resistant and aging-resistant ship functional film is composed of a polytetrafluoroethylene functional layer and a polyimide functional layer; the polytetrafluoroethylene functional layer wraps the surface of the polyimide functional layer; the thickness of the polyimide functional layer is 0.2 mm; the single-layer thickness of the polytetrafluoroethylene functional layer is 0.15 mm.

[0027] Application of a wear-resistant and aging-resistant ship functional film in the field of ship functions. By directly attaching the wear-resistant and aging-resistant ship functional film to the cabin wall or the cabin floor, the technical effects of wear resistance and aging resistance, as well as the functions of moisture-proof and corrosion-resistant, can be achieved.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. Through the surface modification of nano-zinc oxide with perfluorohexylethyl phosphate and the in-situ emulsion polymerization of the modified nano-particles with tetrafluoroethylene, the aging resistance and moisture-proof property of the ship functional film product are improved. The fluorocarbon chain of perfluorohexylethyl phosphate covers the surface of zinc oxide through chemical adsorption, forming a low surface energy barrier, which can effectively inhibit the penetration of moisture and significantly improve the compatibility of nano-zinc oxide and tetrafluoroethylene in-situ emulsion copolymerization. The surface-modified zinc oxide particles form chemical anchoring points during the polymerization process of tetrafluoroethylene, and form an interpenetrating network interface with the polytetrafluoroethylene molecular chain through van der Waals force and physical entanglement, avoiding the particle aggregation defect of the traditional blending method, and enabling the modified nano-particles to be embedded in the polytetrafluoroethylene matrix in a monodisperse state, reducing the stress concentration points. Further, the uniformly dispersed modified nano-particles inhibit the photolysis of the C-F bond in the main chain of polytetrafluoroethylene through the ultraviolet shielding effect. The surface passivation of the modified nano-zinc oxide reduces the generation of catalytic active oxygen, while delaying the oxidative degradation. The dense composite interface further hinders the penetration of oxygen, synergistically improving the antioxidant ability; the fluorocarbon chain of perfluorohexylethyl phosphate and the hydrophobic group of polytetrafluoroethylene form a superhydrophobic topological structure on the surface of the composite film, and the embedded modified nano-particles strengthen the superhydrophobic effect by increasing the surface roughness, resulting in a significant reduction in the water vapor permeability of the functional film.

[0030] 2. By selecting the double anhydride structure of pyromellitic dianhydride and biphenyltetracarboxylic dianhydride and combining it with the rigid fluorinated group of hexafluoroisopropyl diamine, a polyamic acid chain with high regularity is formed under low-temperature polymerization, and the solution vortex is eliminated by the casting film process to realize the pre-orientation arrangement of the molecular chain along the flow direction. Further, the residual stress is eliminated and the cyclization rate is increased by the three-stage gradient heating thermal imidization, enabling the fluorine element to migrate directionally to the film surface to form a surface fluorine-rich layer, effectively improving the corrosion resistance and aging resistance of the functional film product. The fluorine element surface enrichment layer obtained by low-temperature polymerization and casting process can effectively prevent the diffusion and dissolution of ozone, and the ultraviolet shielding effect of the biphenyl structure can also reduce the photo-aging rate. The synergistically generated sub-microcrystalline phase can hinder the lateral propagation of the free radical chain reaction, effectively delaying the aging rate of the functional film under harsh sea conditions, and the fluorine coating layer significantly inhibits the electrochemical corrosion activity of chloride ions. The two processes and the directional selection of monomers together improve the corrosion resistance and aging resistance of the functional film product.

[0031] 3. The annealing treatment process promotes the rearrangement of polyimide molecular chains, and the polyimide film is surface-activated by alkali immersion and ammonia plasma treatment, jointly achieving the effect of improving the aging resistance and toughness of the functional film product. During the annealing process, the benzene ring conjugate system is arranged orderly along the crystal plane, forming a nanoscale spherulite structure, effectively shielding the ultraviolet band of 290 - 320 nm, significantly improving the aging resistance of the polyimide functional layer. At the same time, annealing reduces the torsional angle between imide rings, increases the packing density of molecular chains, and significantly reduces the continuity of oxygen diffusion channels. Sodium hydroxide immersion forms nanoscale pits on the surface of the polyimide film, induces the generation of terminal carboxylic acid groups on the surface, and forms an amino-rich surface layer through subsequent ammonia plasma treatment, significantly increasing the residual compressive stress at the interface and improving the compactness of the polytetrafluoroethylene functional layer prepared on the surface of the polyimide functional layer. The amino-rich cross-linked layer generated by surface activation and the internal spherulite structure produce a synergistic toughening effect. Meanwhile, the amino cross-linked layer can effectively capture free radicals, and together with the dense multi-layer structure, achieves the effect of delaying the aging process of the functional film.

[0032] 4. A precision polytetrafluoroethylene-based film layer is constructed by electrostatic spraying, and the interfacial bonding between the polyimide functional layer and the polytetrafluoroethylene functional layer is further strengthened by a hot pressing process, jointly improving the wear resistance and corrosion resistance of the functional film product. Electrostatic spraying adsorbs ZnONPs / PTFE composite powder through Coulomb force to form a pre-coating, greatly reducing the surface porosity. Meanwhile, the hot pressing process promotes the flow and penetration of polytetrafluoroethylene molecular chains to the amino-rich cross-linked layer on the surface of the polyimide film, forming a gradient interpenetrating interface, significantly improving the bonding strength between the polytetrafluoroethylene functional layer and the polyimide functional layer, and comprehensively improving the strength and toughness of the functional film product. Further, the low friction coefficient of polytetrafluoroethylene and the high hardness of nano-zinc oxide act synergistically to effectively improve the wear resistance of the functional film surface. On this basis, the hot pressing process reduces the surface roughness of the polytetrafluoroethylene functional layer, effectively reducing the friction coefficient and improving the corrosion resistance. In particular, the modified nanoparticles have a slow release effect in the polytetrafluoroethylene matrix, and low-concentration zinc ions can effectively inhibit the current density of electrochemical corrosion, and together with the good hydrophobicity of the polytetrafluoroethylene functional layer, jointly improve the corrosion resistance of the functional film product in the marine environment. Brief Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of the wear-resistant and aging-resistant ship functional film in the present invention.

[0034] In the figure: 1. Polytetrafluoroethylene functional layer; 2. Polyimide functional layer. Detailed Embodiments

[0035] The technical solutions of the present invention will be clearly and completely described below through some embodiments and experimental examples. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0036] Referring to Figure 1 the structural schematic diagram shown, the present invention provides a wear-resistant and aging-resistant ship functional film, a preparation method thereof and an application, and the technical solutions are as follows:

[0037] Example 1

[0038] 110 parts of nano-zinc oxide were dispersed in 300 parts of absolute ethanol at an ultrasonic frequency of 30 kHz to obtain a zinc oxide dispersion; the zinc oxide dispersion was stirred at a rotation speed of 300 rpm at 35 °C, and 10 parts of perfluorohexylethyl phosphate was slowly added. After stirring for 4 hours, the solid product was obtained by centrifugation, and the modified nanoparticles were obtained after washing and drying.

[0039] 100 parts of modified nanoparticles were dispersed in 400 parts of reaction emulsion. Tetrafluoroethylene monomer was introduced at a stirring speed of 250 rpm. After the temperature was raised to 75 °C, ammonium persulfate was added under an operating pressure of 2.0 MPa. After reacting for 6 hours, the introduction of tetrafluoroethylene monomer was stopped, and the emulsion was separated, washed and dried to obtain ZnONPs / PTFE composite powder; the reaction emulsion included: deionized water, methyl formate, acetone, perfluoropropyl vinyl ether and ammonium perfluorooctanoate; the addition amount of ammonium persulfate was 3 ppm relative to deionized water; in the reaction emulsion, the mass ratio of deionized water, methyl formate, acetone, perfluoropropyl vinyl ether and ammonium perfluorooctanoate was 92:2:1:3:2.

[0040] Purified hexafluoroisopropyl diamine and m-phenylenediamine were dissolved in N-methylpyrrolidone under nitrogen protection, the reaction temperature was controlled at 0 °C, and pyromellitic dianhydride and biphenyltetracarboxylic dianhydride were slowly added to the reaction system at a stirring speed of 800 rpm. The solid content of the solution was controlled at 20 wt%, and the reaction was continued for 12 hours to obtain a polyamic acid solution.

[0041] Among them, the addition amount of pyromellitic dianhydride was 22.0 parts, the addition amount of biphenyltetracarboxylic dianhydride was 29.5 parts, the addition amount of hexafluoroisopropyl diamine was 44.5 parts, and the addition amount of m-phenylenediamine was 11.0 parts.

[0042] Among them, the addition amount of N-methylpyrrolidone was 500 parts.

[0043] The polyamic acid solution was filtered through a 0.45 μm filter membrane and then evenly coated on a flat glass substrate. It was heated at a rate of 1 °C / min to 45 °C and then kept warm and dried for 2 hours to obtain a polyamic acid film.

[0044] The polyamic acid film was placed in a vacuum oven. Keeping the operating pressure at 0.2 atm, it was heated at a rate of 5 °C / min to 80 °C and then heat-treated for 30 min. Then it was heated at a rate of 2 °C / min to 150 °C and heat-treated for 60 min. The operating pressure was reduced to 0.1 atm, and it was heated at a rate of 2 °C / min to 320 °C and heat-treated for 90 min. After cooling at a rate of 5 °C / min to 25 °C, the pressure was restored to 1 atm to obtain a polyimide film.

[0045] The polyimide film was heated at a rate of 5 °C / min to 200 °C and heat-treated for 400 min. Then it was cooled at a rate of 2 °C / min to 25 °C to obtain an annealed polyimide film.

[0046] The annealed polyimide film was immersed in a 2 wt% aqueous sodium hydroxide solution and treated for 10 min, then rinsed with deionized water. After drying, it was subjected to ammonia plasma treatment at an operating temperature of 350 °C, where the radio frequency power was 200 W, the radio frequency was 13.56 MHz, the ammonia flow rate was 40 sccm, and the operating pressure was 10 Pa. After treatment for 5 min, a polyimide functional layer was obtained.

[0047] Under the operating parameters of a voltage of 50 kV, a spraying air pressure of 0.2 MPa, a spraying distance of 20 cm, and an overlapping rate of 30%, the ZnONPs / PTFE composite powder was electrostatically sprayed and coated on the surface of the polyimide functional layer.

[0048] The polyimide functional layer coated with the ZnONPs / PTFE composite powder was placed in a mold, heated at 330 °C for 30 min, and the polyimide functional layer was pressed at a pressure of 1 MPa. After the treatment was completed, it was heated to 510 °C in an argon atmosphere and cooled to 25 °C at a cooling rate of 5 °C / min to prepare a polytetrafluoroethylene functional layer on the surface of the polyimide functional layer.

[0049] The prepared wear-resistant and aging-resistant ship functional film consists of a polytetrafluoroethylene functional layer and a polyimide functional layer. The polytetrafluoroethylene functional layer wraps the surface of the polyimide functional layer; the thickness of the polyimide functional layer is 0.2 mm; the single-layer thickness of the polytetrafluoroethylene functional layer is 0.15 mm.

[0050] Examples 2 - 20 are different from Example 1 in process parameters, and the process steps are the same. The changes in parameters are summarized in Tables 1 and 2.

[0051] Table 1 Process parameter changes of Examples 1 - 20 (I)

[0052]

[0053] Table 2 Process parameter changes of Examples 1 - 20 (II)

[0054]

[0055] Comparative Example 1

[0056] Different from Example 1, γ - aminopropyltriethoxysilane was used to modify the surface of nano - zinc oxide instead of perfluorohexylethyl phosphate, and other process parameters were the same.

[0057] Comparative Example 2

[0058] Different from Example 1, in - situ emulsion polymerization was not carried out. The modified nanoparticles were blended with the polytetrafluoroethylene emulsion after emulsion polymerization, and after drying, they were used to replace the ZnONPs / PTFE composite powder, and other process parameters were the same.

[0059] Comparative Example 3

[0060] Different from Example 6, diphenyltetracarboxylic dianhydride was not added, and isophthalic tetracarboxylic dianhydride in an equimolar amount was used instead, and other process parameters were the same.

[0061] Comparative Example 4

[0062] Different from Example 6, hexafluoroisopropyl diamine was not added, and m - phenylenediamine in an equimolar amount was used instead, and other process parameters were the same.

[0063] Comparative Example 5

[0064] Different from Example 6, during the low - temperature polymerization process, all monomers were added simultaneously, and other process parameters were the same.

[0065] Comparative Example 6

[0066] Different from Example 6, the casting film - forming process was not carried out, and the polyamic acid film was prepared by spin - coating method, and other process parameters were the same.

[0067] Comparative Example 7

[0068] Different from Example 11, the annealing treatment process was not carried out, and other process parameters were the same.

[0069] Comparative Example 8

[0070] Different from Example 11, the order of the annealing treatment process and the surface activation process was exchanged, and other process parameters were the same.

[0071] Comparative Example 9

[0072] Different from Example 16, instead of using the electrostatic spraying process, the ZnONPs / PTFE composite powder was dispersed in tetrahydrofuran and then coated on the surface of the polyimide functional layer 2, and other process parameters were the same.

[0073] Comparative Example 10

[0074] Different from Example 16, during the hot pressing process, the pressure on the polyimide functional layer 2 was increased to 2 MPa, and other process parameters were the same.

[0075] Comparative Example 11

[0076] Different from Example 16, during the hot pressing process, the pressure on the polyimide functional layer 2 was reduced to 0.1 MPa, and other process parameters were the same.

[0077] Experimental Example 1

[0078] The water vapor permeability and aging resistance of the ship functional films prepared in Examples 1-5 and Comparative Examples 1-2 were tested, and the obtained results were summarized in Table 3.

[0079] The test method for water vapor permeability referred to the GB / T 1037-2021 standard. The experimental conditions were a temperature of 23.0°C ± 0.5°C and a relative humidity of 90% ± 2%. The weight loss method was adopted for testing, and the water vapor transmission coefficient Pv (g·cm / (cm 2 ·s·Pa)) was used to characterize the water vapor permeability of the functional film.

[0080] The test method for aging resistance was as follows: with a power of 100 uw / cm 2 and a wavelength of 365 nm ultraviolet light continuously irradiating the sample functional film for 24 h, and then the water vapor permeability was tested again. The increase amplitude of Pv was used as the judgment standard for aging resistance. The larger the increase amplitude, the worse the aging resistance.

[0081] Table 3 Water vapor permeability and aging resistance of the ship functional films prepared in Examples 1-5 and Comparative Examples 1-2

[0082]

[0083] As shown in the water vapor permeability and aging resistance data in Table 3, the ship functional films prepared in Examples 1-5 have low water vapor permeability and good aging resistance, and the change of process parameters has little effect on the performance of the obtained functional films. In Comparative Example 1, γ-aminopropyltriethoxysilane was used for modification. The alkyl chain of the silane coupling agent could not form a low surface energy barrier, resulting in the agglomeration of nanoparticles in the matrix. At the same time, the loss of surface passivation effect caused a large amount of generation of photocatalytic reactive oxygen, resulting in a significant increase in water vapor permeability. In Comparative Example 2, when the in-situ polymerization was replaced by the blending method, the nanoparticles could not be uniformly dispersed, resulting in stress concentration. The increase in interfacial porosity led to an increase in water vapor permeability and a decrease in aging resistance, confirming the key role of in-situ polymerization in constructing a multi-level protection structure. In summary, the surface-modified nanoparticles form a monodispersed state in the polytetrafluoroethylene matrix through emulsion in-situ polymerization, reduce the interfacial energy through physical entanglement and chemical anchoring, inhibit the formation of water penetration channels, and at the same time enhance the densification of the composite interface through the interpenetrating network formed by in-situ polymerization, hinder the oxidation chain reaction caused by oxygen diffusion, synergistically improve the aging resistance of the functional film product, and improve its water vapor permeability.

[0084] Experimental Example 2

[0085] The corrosion resistance and aging resistance of the ship functional films prepared in Examples 6-10 and Comparative Examples 3-6 were tested. The obtained data are summarized in Table 4.

[0086] The test method for corrosion resistance is as follows: at 25 °C, the sample ship functional film was immersed in hydrochloric acid with a pH value of 1.0 for 24 hours, and the blank control group was immersed in deionized water for 24 hours. The elongation at break of the two was compared. Taking the blank control group as 100%, the percentage of the elongation at break of the experimental group ship functional film relative to the blank control group was recorded. The larger the percentage, the better the corrosion resistance.

[0087] The test method for aging resistance is as follows: at a power of 100 uw / cm 2 and a wavelength of 365 nm, the sample functional film was continuously irradiated with ultraviolet light for 24 h, and then the corrosion resistance test was carried out again. The percentage of the elongation at break relative to the blank control group was used as the judgment standard for aging resistance. The larger the percentage, the better the aging resistance.

[0088] Table 4 Corrosion resistance and aging resistance of ship functional films prepared in Examples 6-10 and Comparative Examples 3-6

[0089]

[0090] As shown in the corrosion resistance and aging resistance data in Table 4, the functional films prepared in Examples 6-10 have good corrosion resistance and aging resistance, and stable performance. In Comparative Example 3, due to the absence of biphenyltetracarboxylic dianhydride, a conjugated ultraviolet shielding structure could not be formed, resulting in a significant reduction in the elongation at break after ultraviolet aging. In Comparative Example 4, using m-phenylenediamine to replace hexafluoroisopropyl diamine led to a significant reduction in the interfacial fluorine coverage rate, resulting in a significant reduction in both corrosion resistance and aging resistance. In Comparative Example 5, due to the synchronous addition of polymerization monomers, the degree of chain entanglement was insufficient, the surface fluorine coverage rate was affected, and it was difficult to inhibit local corrosion, resulting in a large loss of aging resistance. In Comparative Example 6, because the casting process was not used, the film-forming defects accumulated seriously, and both corrosion resistance and aging resistance were affected. In summary, under the conditions of low-temperature polymerization reaction, the slow feeding of isophthalic acid / biphenyl dianhydride and hexafluoroisopropyl diamine ensures the orderly growth of polyamic acid chains. The high regularity of the molecular chains improves the cyclization rate of thermal imidization, induces the directional migration of fluorine elements and forms a continuous surface fluorine coverage layer, which can prevent the penetration of chloride ions and significantly improve the corrosion resistance of the functional film. At the same time, the rigid conjugated structure of biphenyltetracarboxylic dianhydride forms an ultraviolet absorption barrier through π-π stacking, reduces the ultraviolet transmittance, and eliminates the molecular chain dislocation defects formed by eddy currents through the casting process. The regular arrangement of sub-microcrystalline phases greatly extends the lateral propagation path of free radicals, significantly reduces the loss rate of elongation at break after photoaging, and improves the aging resistance of the functional film.

[0091] Experimental Example 3

[0092] The toughness and aging resistance of the ship functional films prepared in Examples 11-15 and Comparative Examples 7-8 were tested, and the results are summarized in Table 5.

[0093] The test method for toughness is as follows: Referring to the experimental method of ASTM D882, the tensile strength at break of the test sample ship functional film was tested. The greater the tensile strength at break, the better the toughness of the test sample.

[0094] The test method for aging resistance is as follows: At a power of 100 uw / cm 2 , after continuously irradiating the test sample functional film with ultraviolet light with a wavelength of 365 nm for 24 h, the toughness test was carried out again. The percentage of the tensile strength at break after ultraviolet irradiation relative to the original tensile strength at break was used as the judgment standard for aging resistance. The larger the percentage, the better the aging resistance.

[0095] Table 5 Toughness and aging resistance of ship functional films prepared in Examples 11-15 and Comparative Examples 7-8

[0096] Breaking tensile strength (MPa) Aging resistance (%) Example 11 136 97％ Example 12 118 95％ Example 13 125 95％ Example 14 127 96％ Example 15 130 94％ Comparative Example 7 96 90％ Comparative Example 8 117 82％

[0097] As shown in the toughness and anti-aging data in Table 5, Examples 11-15 all have high toughness and anti-aging properties, and the relative performance differences are very small. In Comparative Example 7, since annealing was not carried out, microcrystals with uneven sizes were formed inside the functional film, resulting in stress concentration and a decrease in the fracture strength. In Comparative Example 8, due to surface activation followed by annealing, the high-temperature annealing damaged the amino crosslinking layer, the free radical scavenging efficiency decreased, and the disordered interface led to an increase in the ultraviolet transmittance, resulting in a significant decrease in the anti-aging property. In summary, the annealing process promotes the ordered arrangement of the polyimide benzene ring, improves the ability to reflect ultraviolet rays. Combining the 2wt% alkali treatment in surface activation, a nitrogen-rich substrate layer is formed on the surface of the polyimide functional layer 2 through ammonia plasma treatment. While improving the adhesion of the polytetrafluoroethylene functional layer 1, the crosslinked amino group scavenging free radicals is also synergistically improved, ensuring the toughness and anti-aging property of the functional film product.

[0098] Experimental Example 4

[0099] The abrasion resistance and corrosion resistance of the ship functional films prepared in Examples 16-20 and Comparative Examples 9-11 were tested, and the obtained results are summarized in Table 6.

[0100] The test method for corrosion resistance refers to Experimental Example 2.

[0101] The test method for abrasion resistance is as follows: The sample functional film is cut into a circle with a diameter of 100 mm. Under a load of 1000 g, the CS-10 wear wheel is used to perform wear treatment on the surface of the sample functional film at a rotation speed of 60 rpm for 20 min. The abrasion resistance of the functional film is characterized by the wear mass loss. The greater the wear mass loss, the worse the abrasion resistance.

[0102] Table 6 Abrasion resistance and corrosion resistance of the ship functional films prepared in Examples 16-20 and Comparative Examples 9-11

[0103]

[0104] As shown in the abrasion resistance and corrosion resistance data in Table 6, Examples 16-20 have excellent abrasion resistance and relatively high corrosion resistance. In Comparative Example 9, since the electrostatic spraying process was not used, the porosity of the polytetrafluoroethylene functional layer 1 increased, and there were a large number of stress concentration points during the wear process, resulting in a decrease in abrasion resistance and a certain degree of reduction in corrosion resistance. In Comparative Example 10, the gradient structure of the bonding interface between the polytetrafluoroethylene functional layer 1 and the polyimide functional layer 2 was damaged due to excessive compression, resulting in a decrease in both abrasion resistance and corrosion resistance. In Comparative Example 11, due to too low pressure, insufficient interface penetration, and too low bonding strength between the polytetrafluoroethylene functional layer 1 and the polyimide functional layer 2, significant losses in abrasion resistance and corrosion resistance were caused. In summary, the 50 kV electrostatic spraying significantly reduced the porosity of the ZnONPs / PTFE composite powder pre-coating layer. Combining with the 1 MPa hot pressing process, the polytetrafluoroethylene molecular chains were embedded into the ammonia-rich layer on the surface of the polyimide functional layer 2, forming a gradient interpenetrating interface, greatly improving the bonding strength. Moreover, part of the modified nanoparticles entered the surface of the polyimide functional layer 2, reducing the friction coefficient of the functional film product, improving its abrasion resistance, and synergistically enhancing its corrosion resistance.

[0105] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of an abrasion-resistant and aging-resistant ship functional film, characterized in that: The preparation method is as follows: Surface-modify the nano-zinc oxide to obtain modified nano-particles; Perform in-situ emulsion polymerization reaction on the modified nano-particles and tetrafluoroethylene to obtain ZnONPs / PTFE composite powder; Perform low-temperature polymerization reaction on the purified pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, hexafluoroisopropyl diamine and m-phenylenediamine under nitrogen protection to obtain a polyamic acid solution; Cast the polyamic acid solution into a film to obtain a polyamic acid film; Perform thermal imidization on the polyamic acid film to obtain a polyimide film; Perform annealing treatment and surface activation on the polyimide film to obtain a polyimide functional layer (2); Coat the ZnONPs / PTFE composite powder on the surface of the polyimide functional layer (2) by electrostatic spraying, and then perform heating and pressing to obtain a polytetrafluoroethylene functional layer (1); The polytetrafluoroethylene functional layer (1) and the polyimide functional layer (2) together form the wear-resistant and aging-resistant ship functional film.

2. The preparation method of a wear-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of the surface modification is as follows: By mass, disperse 110 parts of the nano-zinc oxide in 300 parts of absolute ethanol at an ultrasonic frequency of 30 kHz to obtain a zinc oxide dispersion; Keep stirring the zinc oxide dispersion at a speed of 300 rpm at 35 °C, slowly add 10 - 15 parts of perfluorohexylethyl phosphate, after stirring for 4 - 6 hours, centrifuge to obtain a solid product, and after washing and drying, obtain the modified nano-particles.

3. The preparation method of a wear-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of the in-situ emulsion polymerization reaction is as follows: By mass, disperse 100 parts of the modified nano-particles in 400 parts of a reaction emulsion, introduce tetrafluoroethylene monomer at a stirring speed of 250 rpm, raise the temperature to 75 - 80 °C, and add ammonium persulfate under an operating pressure of 2.0 MPa, after reacting for 6 - 8 hours, stop introducing the tetrafluoroethylene monomer, perform liquid separation, washing and drying on the emulsion to obtain the ZnONPs / PTFE composite powder; The reaction emulsion includes: deionized water, methyl formate, acetone, perfluoropropyl vinyl ether and ammonium perfluorooctanoate; The addition amount of the ammonium persulfate is 3 - 5 ppm relative to deionized water.

4. The preparation method of a wear-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of the low-temperature polymerization reaction is as follows: Dissolve the purified hexafluoroisopropyl diamine and m-phenylenediamine in N-methylpyrrolidone under nitrogen protection, control the reaction temperature at 0 - 10 °C, slowly add the pyromellitic dianhydride and biphenyltetracarboxylic dianhydride to the reaction system at a stirring speed of 800 - 1200 rpm, control the solid content of the solution at 20 - 25 wt%, and continuously react for 12 - 15 hours to obtain the polyamic acid solution.

5. The preparation method of a wear-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of casting film is as follows: The polyamic acid solution is filtered through a 0.45 μm filter membrane and then uniformly coated on a flat glass substrate. It is heated at a rate of 1 °C / min to 45 °C and then kept for drying for 2 hours to obtain the polyamic acid film. The process of thermal imidization is as follows: The polyamic acid film is placed in a vacuum oven, maintaining an operating pressure of 0.2 atm. It is heated at a rate of 5 °C / min to 80 °C and then heat-treated for 30 min, and then heated at a rate of 2 °C / min to 150 °C and heat-treated for 60 min. The operating pressure is reduced to 0.1 atm, and it is heated at a rate of 2 °C / min to 320 °C and heat-treated for 90 min. It is cooled at a rate of 5 °C / min to 25 °C and then the pressure is restored to 1 atm to obtain the polyimide film.

6. The preparation method of a wear-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of annealing treatment is as follows: The polyimide film is heated at a rate of 5 °C / min to 200 °C and then heat-treated for 400 min, and then cooled at a rate of 2 - 3 °C / min to 25 °C to obtain the annealed polyimide film. The process of surface activation is as follows: The annealed polyimide film is soaked in a 2 wt% sodium hydroxide aqueous solution for 10 min and then rinsed with deionized water. After drying, it is subjected to ammonia plasma treatment at an operating temperature of 350 °C, where the radio frequency power is 200 W, the radio frequency frequency is 13.56 MHz, the ammonia flow rate is 40 - 50 sccm, and the operating pressure is 10 Pa. After treatment for 5 min, the polyimide functional layer (2) is obtained.

7. The preparation method of an abrasion-resistant and aging-resistant ship functional film according to claim 1, characterized in that: The process of heating and pressing is as follows: The polyimide functional layer (2) coated with the ZnONPs / PTFE composite powder is placed in a mold, heated at 330 °C for 30 min, and the polyimide functional layer (2) is pressed at a pressure of 1 MPa. After the treatment is completed, it is heated to 510 °C in an argon atmosphere and cooled to 25 °C at a cooling rate of 5 °C / min to prepare the polytetrafluoroethylene functional layer (1) on the surface of the polyimide functional layer (2).

8. A wear-resistant and aging-resistant ship functional film, characterized in that: The wear-resistant and aging-resistant ship functional film includes: a polytetrafluoroethylene functional layer (1) and a polyimide functional layer (2); the wear-resistant and aging-resistant ship functional film is prepared by the preparation method described in any one of claims 1 - 7; the polytetrafluoroethylene functional layer (1) wraps the surface of the polyimide functional layer (2); the thickness of the polyimide functional layer (2) is 0.2 mm; the single-layer thickness of the polytetrafluoroethylene functional layer (1) is 0.15 mm.

9. Application of a wear-resistant and aging-resistant ship functional film, characterized in that: The application of a wear-resistant and aging-resistant ship functional film as described in claim 8 in the field of ship interior decoration; the way the wear-resistant and aging-resistant ship functional film is applied to ship interior decoration is: directly attaching the wear-resistant and aging-resistant ship functional film to the cabin wall or the cabin floor.

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