A method of enhancing the bond strength of a polymer to an inorganic coating

Abstract

This invention provides a method for enhancing the adhesion between a polymer and an inorganic coating. The method includes: (1) providing a polymer substrate; (2) using an adhesive to composite ceramic fibers onto the surface of the polymer substrate to obtain a fiber transition layer; and (3) composite an inorganic coating onto the surface of the fiber transition layer to enhance the adhesion between the polymer substrate and the inorganic coating. In this invention, by composited with a fiber transition layer between the polymer substrate and the inorganic coating, the fiber transition layer can form a three-dimensional entangled bulk structure with the polymer substrate and the inorganic coating, thereby transforming the two-dimensional interface between the polymer substrate and the inorganic coating into a three-dimensional interface, and thus significantly improving the adhesion between the polymer substrate and the inorganic coating.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, and in particular to a method for enhancing the bonding strength between polymers and inorganic coatings. Background Technology

[0002] Polymer materials possess advantages such as good dimensional stability, high impact strength, excellent corrosion resistance, and lightweight properties, leading to their widespread application in numerous fields including automotive, aerospace, building materials, electronics manufacturing, semiconductor devices, and textiles. To meet certain extreme conditions and specific functional requirements, researchers have developed a novel composite material by using a polymer material as a substrate and bonding an inorganic coating to its surface. Compared to pure polymer materials, this new composite material exhibits superior thermal, mechanical, electrical, flame-retardant, and optical properties.

[0003] For novel polymer-inorganic composite materials, the bonding strength between the polymer and the inorganic coating significantly affects the overall performance of the composite. Therefore, improving the interfacial bonding strength between the polymer substrate and the inorganic coating is crucial to ensuring the overall performance of the novel composite. However, due to the significant differences in molecular structure between most polymer materials and inorganic coatings, the bonding strength between the polymer substrate and the inorganic coating is often poor. This leads to cracking and peeling of the inorganic coating, resulting in poor overall performance of the novel composite.

[0004] Therefore, there is an urgent need to provide a method to enhance the adhesion between polymers and inorganic coatings to solve the above problems. Summary of the Invention

[0005] This invention provides a method for enhancing the adhesion between polymers and inorganic coatings, which can significantly improve the adhesion between polymers and inorganic coatings.

[0006] This invention provides a method for enhancing the adhesion between polymers and inorganic coatings, the method comprising the following steps:

[0007] (1) Provide a polymer substrate;

[0008] (2) A ceramic fiber is composited onto the surface of the polymer substrate using an adhesive to obtain a fiber transition layer;

[0009] (3) An inorganic coating is laminated onto the surface of the fiber transition layer to enhance the bonding force between the polymer substrate and the inorganic coating.

[0010] Preferably, in step (1), the polymer substrate is a polycarbonate material, a polymethyl methacrylate material, or a polyethylene material.

[0011] Preferably, in step (2), the ceramic fiber cloth is at least one of carbon fiber cloth, glass fiber cloth, alumina fiber cloth, high silica fiber cloth, mullite fiber cloth or zirconium oxide fiber cloth.

[0012] Preferably, the areal density of the ceramic fiber cloth is 1.5–4.0 g / cm³. 3 The tensile strength is 100-3000 MPa.

[0013] Preferably, in step (2), before the composite ceramic fiber cloth is applied to the surface of the polymer substrate, the polymer substrate and the ceramic fiber cloth are respectively activated.

[0014] Preferably, the activation treatment is performed by plasma treatment, acid / alkali treatment, sandpaper polishing treatment, silane coupling agent treatment, or oxidation treatment.

[0015] Preferably, in step (2), the adhesive is at least one of epoxy resin or phenolic resin.

[0016] Preferably, in step (2), the coating thickness of the adhesive is 0.5 to 2 mm, and the thickness of the ceramic fiber cloth is 1 to 3 mm.

[0017] Preferably, in step (3), the inorganic coating is obtained by spraying or brushing a mixed solution containing ceramic powder, adhesive and water onto the surface of the fiber transition layer;

[0018] The ceramic powder is at least one of alumina powder, titanium dioxide powder, or silicon dioxide powder; the adhesive is at least one of epoxy resin or phenolic resin.

[0019] Preferably, in the mixed solution, the mass ratio of ceramic powder, adhesive and water is (3-5):(1-2):(2-4).

[0020] Preferably, in step (3), after the inorganic coating is laminated onto the surface of the fiber transition layer, the step further includes curing the polymer substrate as a whole;

[0021] The curing temperature is 100–200℃, and the curing time is 1.5–2.5 h.

[0022] Preferably, the bonding strength of the inorganic coating on the polymer substrate surface is greater than 26 MPa.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] (1) In this invention, by composite fiber transition layer between polymer substrate and inorganic coating, the fiber transition layer can form a three-dimensional entangled bulk structure between polymer substrate and inorganic coating, thereby transforming the two-dimensional interface between polymer substrate and inorganic coating into a three-dimensional interface, thereby greatly improving the bonding force between polymer substrate and inorganic coating.

[0025] (2) The method in this invention has the advantages of simple process, low raw material loss and suitability for mass production. In addition, the method has a wide range of applications and is suitable for a variety of polymer substrates and inorganic coatings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of a method for enhancing the bonding force between polymers and inorganic coatings provided by the present invention;

[0028] Figure 2 This is a structural diagram of a composite material obtained by using a method for enhancing the bonding force between a polymer and an inorganic coating provided by this invention;

[0029] In the diagram: 100 - polymer substrate; 200 - fiber transition layer; 300 - inorganic coating. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] As mentioned earlier, the interfacial bonding strength between the inorganic coating and the polymer substrate significantly affects the overall properties of novel composite materials formed by the coating and the polymer substrate. However, due to the significant differences in molecular structure between most polymer materials and inorganic coatings, they cannot form chemical bonds or exhibit electrostatic or van der Waals attraction. This leads to cracking and peeling of the inorganic coating on the polymer substrate surface. Currently, surface treatment of the polymer surface is mainly used to improve the interfacial bonding strength between the two materials. While this method can improve the bonding strength to varying degrees, in some applications requiring thicker inorganic coatings, insufficient bonding between the inorganic coating and the polymer substrate still results in cracking and peeling.

[0032] Therefore, based on the above issues, such as Figure 1 and Figure 2 As shown, this embodiment of the invention provides a method for enhancing the adhesion between a polymer and an inorganic coating, the method comprising the following steps:

[0033] (1) Provide a polymer substrate 100;

[0034] (2) A ceramic fiber is composited on the surface of the polymer substrate 100 using an adhesive to obtain a fiber transition layer 200.

[0035] (3) An inorganic coating 300 is laminated on the surface of the fiber transition layer 200 to enhance the bonding force between the polymer substrate and the inorganic coating.

[0036] In this invention, by composite fiber transition layer between polymer substrate and inorganic coating, the fiber transition layer can form a three-dimensional entangled bulk structure with polymer substrate and inorganic coating, thereby transforming the two-dimensional interface between polymer substrate and inorganic coating into a three-dimensional interface, and thus greatly improving the bonding force between polymer substrate and inorganic coating.

[0037] According to some preferred embodiments, in step (1), the polymer substrate is a polycarbonate material, a polymethyl methacrylate material, or a polyethylene material.

[0038] According to some preferred embodiments, in step (2), the ceramic fiber cloth is at least one of carbon fiber cloth, glass fiber cloth, alumina fiber cloth, high silica fiber cloth, mullite fiber cloth or zirconium oxide fiber cloth.

[0039] According to some preferred embodiments, the areal density of the ceramic fiber cloth is 1.5–4.0 g / cm³. 3 (For example, it can be 1.5g / cm) 3 2.0g / cm 3 2.5g / cm 33.0g / cm 3 3.5g / cm 3 Or 4.0g / cm 3 The tensile strength is 100 to 3000 MPa (for example, it can be 100 MPa, 200 MPa, 500 MPa, 800 MPa, 1000 MPa, 2000 MPa or 3000 MPa).

[0040] In this embodiment, ceramic fiber cloth is composited between a polymer substrate and an inorganic coating, serving as a transition layer. An adhesive is used to bond the ceramic fiber cloth to the polymer substrate. Then, an inorganic coating is composited onto the surface of the ceramic fiber cloth. Both the ceramic fiber cloth and the polymer substrate, as well as the inorganic coating, exhibit good interfacial adhesion. Furthermore, by controlling the areal density and tensile strength of the ceramic fiber cloth, not only is good flatness of the inorganic coating on the surface of the ceramic fiber cloth ensured, but also strong interfacial adhesion between the inorganic coating and the ceramic fiber cloth. It should be noted that in this embodiment, the polymer substrate and the ceramic fiber cloth include, but are not limited to, the materials described above.

[0041] According to some preferred embodiments, in step (2), before the composite ceramic fiber cloth is applied to the polymer substrate surface, an activation treatment is performed on the polymer substrate and the ceramic fiber cloth respectively.

[0042] According to some preferred embodiments, the activation treatment is carried out by plasma treatment, sandpaper polishing, acid / alkali treatment, silane coupling agent treatment or oxidation treatment.

[0043] In this embodiment, before applying the ceramic fiber cloth to the polymer substrate surface, it is preferable to first activate the surface of the polymer substrate and the upper and lower surfaces of the ceramic fiber cloth respectively. The activation treatment can not only further enhance the bonding force between the polymer substrate and the adhesive, but also further enhance the bonding force between the ceramic fiber cloth and the adhesive and between the ceramic fiber cloth and the inorganic coating, thereby significantly enhancing the interfacial bonding force between the polymer substrate and the inorganic coating.

[0044] It should be noted that the activation treatment methods used in this embodiment are all common methods in the prior art. This embodiment does not specifically limit the specific conditions of the treatment method, and those skilled in the art can adjust them according to actual operational needs. For example, plasma treatment can be performed on the polymer substrate surface using oxygen or argon as the reactive gas for 5-10 minutes; for example, the polymer substrate surface can be activated by sanding or ball milling, specifically, sanding for 5-10 minutes or ball milling for 2-5 minutes; for example, the polymer substrate surface can be soaked in 65% nitric acid for 4-6 hours; for another example, the ultrasonic polymer substrate can be soaked in a 5% vinyltriethoxysilane or vinyltrimethoxysilane solution for 10-30 minutes; for yet another example, the substrate surface can be treated by depositing graphene oxide on the polymer substrate using an electrochemical oxidation deposition method.

[0045] According to some preferred embodiments, in step (2), the adhesive is at least one of epoxy resin or phenolic resin.

[0046] According to some preferred embodiments, in step (2), the thickness of the adhesive is 0.5 to 2 mm (for example, it can be 0.5 mm, 1 mm, 1.5 mm or 2 mm), and the thickness of the fiber transition layer is 1 to 3 mm (for example, it can be 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm).

[0047] In this embodiment, a polymer adhesive is coated on the surface of the polymer substrate. The adhesive can be epoxy resin or phenolic resin, which has good adhesion to both the polymer substrate and the fiber transition layer. It should be noted that the thickness of the adhesive in this embodiment is preferably less than the thickness of the fiber transition layer. That is, the thickness of the polymer adhesive coated on the surface of the polymer substrate is sufficient to bond the fiber transition layer without completely penetrating it. This helps to ensure good adhesion between the polymer substrate and the fiber transition layer. If the thickness of the adhesive is too low or too high, it will not be conducive to ensuring good adhesion between the polymer substrate and the fiber transition layer.

[0048] According to some preferred embodiments, in step (3), the inorganic coating is obtained by spraying or brushing a mixed solution containing ceramic powder, adhesive and water onto the surface of the fiber transition layer;

[0049] The ceramic powder is at least one of alumina powder, titanium dioxide powder, or silicon dioxide powder; the adhesive is at least one of epoxy resin or phenolic resin.

[0050] In this embodiment, the inorganic coating is preferably an alumina coating, a titanium dioxide coating, or a silicon dioxide coating, but is not limited to these types of inorganic coatings. The types of ceramic powder and adhesive in the inorganic coating can be adjusted according to actual needs, and other modified inorganic coatings can also be used. Simultaneously, the thickness of the inorganic coating can be adjusted according to actual needs. While ensuring good interfacial adhesion between the inorganic coating and the polymer substrate, the maximum thickness of the inorganic coating in this embodiment can reach 2 mm.

[0051] According to some preferred embodiments, in the mixed solution, the mass ratio between ceramic powder, adhesive and water is (3-5):(1-2):(2-4) (for example, it can be 3:1:2, 4:1:3, 5:1:4, 4:2:2 or 5:2:4).

[0052] In this embodiment, by preferably using the above-mentioned range in the proportions of the components in the inorganic coating, not only can the inorganic coating be guaranteed to have good smoothness and functionality, but also the bonding force between the inorganic coating and the fiber transition layer can be further guaranteed.

[0053] According to some preferred embodiments, after the inorganic coating is laminated onto the surface of the fiber transition layer, the step of curing the polymer substrate as a whole is further included.

[0054] The curing temperature is 100-200℃ (e.g., 100℃, 120℃, 150℃, 180℃ or 200℃), and the curing time is 1.5-2.5h (e.g., 1.5h, 2h or 2.5h).

[0055] In this embodiment, after the inorganic coating is laminated onto the fiber transition layer surface of the polymer substrate, the entire polymer substrate is first dried at room temperature (25-28°C) for 24 hours. Then, it is placed in a mold and dried and cured in an oven at 100-200°C for 1.5-2.5 hours. This allows the adhesive on the surface of the polymer substrate and the adhesive in the inorganic coating to cure, thereby enhancing the bonding force between the polymer substrate and the inorganic coating.

[0056] It should be noted that, after the fiber transition layer is laminated onto the surface of the polymer substrate, the polymer substrate can be placed in an oven to allow the adhesive on the surface of the polymer substrate to cure. Alternatively, after the inorganic coating is laminated onto the surface of the fiber transition layer, the polymer substrate can be placed in an oven to allow the adhesive and inorganic coating on the surface of the polymer substrate to cure together.

[0057] According to some preferred embodiments, the inorganic coating has a bonding strength greater than 26 MPa on the polymer substrate surface.

[0058] This invention utilizes a composite transition layer between a polymer substrate and an inorganic coating, combined with traditional surface modification methods, to achieve strong interfacial adhesion between both the polymer substrate and the inorganic coating and the fiber transition layer. This significantly enhances the bonding force between the polymer substrate and the inorganic coating, resulting in an interfacial bonding force of up to 32 MPa. This method provides an economical and convenient way to improve the interfacial bonding force of organic polymer composite coating materials. Furthermore, the method of this invention has the advantages of simple process, low raw material loss, suitability for mass production, and wide applicability to various polymer substrate materials and inorganic coatings.

[0059] To more clearly illustrate the technical solution and advantages of the present invention, the following describes in detail a method for enhancing the bonding force between polymers and inorganic coatings through several embodiments.

[0060] Example 1:

[0061] (1) Provide a polymer substrate (polycarbonate) and sand the surface of the polymer substrate with sandpaper for 5 minutes;

[0062] (2) Using argon as the reactive gas, the upper and lower surfaces of the ceramic fiber cloth (1 mm alumina fiber cloth) were subjected to plasma treatment for 5 min. Then, a 0.5 mm layer of adhesive (epoxy resin) was coated on the surface of the polymer substrate, and the plasma-treated ceramic fiber cloth was laminated onto the adhesive surface to obtain a fiber transition layer; wherein, the areal density of the alumina fiber cloth was 3 g / cm³. 3 The tensile strength is 2000 MPa;

[0063] (3) Ceramic powder (alumina powder), adhesive (epoxy resin) and water are mixed in a mass ratio of 4:1:3 to obtain a mixed solution. The mixed solution is sprayed onto the surface of the fiber transition layer at room temperature (25°C). After drying at room temperature (25°C) for 24 hours, the polymer substrate is placed in a mold and dried and cured in an oven at 150°C for 2 hours to enhance the bonding force between the polymer substrate and the inorganic coating.

[0064] Example 2:

[0065] (1) Provide a polymer substrate (polycarbonate) and sand the surface of the polymer substrate with sandpaper for 5 minutes;

[0066] (2) After soaking ceramic fiber cloth (2mm carbon fiber cloth) in 65% nitric acid for 6 hours, a 1mm layer of adhesive (epoxy resin) is coated on the surface of the polymer substrate, and the treated ceramic fiber cloth is then laminated onto the adhesive surface to obtain a fiber transition layer; wherein, the areal density of the carbon fiber cloth is 1.5g / cm³. 3 The fracture strength is 2500 MPa;

[0067] (3) Ceramic powder (alumina powder), adhesive (epoxy resin) and water are mixed in a mass ratio of 4:1:3 to obtain a mixed solution. The mixed solution is sprayed onto the surface of the fiber transition layer at room temperature (25°C). After drying at room temperature (25°C) for 24 hours, the polymer substrate is placed in a mold and dried and cured in an oven at 150°C for 2 hours to enhance the bonding force between the polymer substrate and the inorganic coating.

[0068] Example 3:

[0069] (1) Provide a polymer substrate (polycarbonate) and use argon as the reactive gas to perform surface plasma treatment on the polymer substrate for 5 min;

[0070] (2) Using argon as the reactive gas, the upper and lower surfaces of the ceramic fiber cloth (3mm high-silica fiber cloth) were subjected to plasma treatment for 5 minutes. Then, a 2mm layer of adhesive (phenolic resin) was coated on the surface of the polymer substrate, and the plasma-treated ceramic fiber cloth was laminated onto the adhesive surface to obtain a fiber transition layer; wherein, the areal density of the high-silica fiber cloth was 2.5g / cm³. 3 The tensile strength is 1000 MPa;

[0071] (3) Ceramic powder (titanium dioxide powder), adhesive (epoxy resin) and water are mixed in a mass ratio of 4:2:2 to obtain a mixed solution. The mixed solution is sprayed onto the surface of the fiber transition layer at room temperature (25°C). After drying at room temperature (25°C) for 24 hours, the polymer substrate is placed in a mold and dried and cured in an oven at 150°C for 2 hours to enhance the bonding force between the polymer substrate and the inorganic coating.

[0072] Example 4:

[0073] Example 4 is basically the same as Example 1, except that: in step (1), the polymer substrate is polymethyl methacrylate, and argon is used as the reactive gas to perform surface plasma treatment on the polymer substrate for 5 min; in step (2), the ceramic fiber cloth (1 mm alumina fiber cloth) is soaked in 65% nitric acid for 6 h.

[0074] Example 5:

[0075] Example 5 is basically the same as Example 1, except that in step (2), the areal density of the alumina fiber cloth is 0.5 g / cm³. 3 .

[0076] Example 6:

[0077] Example 6 is basically the same as Example 1, except that in step (2), the areal density of the alumina fiber cloth is 5.0 g / cm³.3 .

[0078] Example 7:

[0079] Example 7 is basically the same as Example 1, except that in step (2), a 1 mm layer of adhesive (epoxy resin) is coated on the surface of the polymer substrate.

[0080] Example 8:

[0081] Example 8 is basically the same as Example 1, except that in step (1), the polymer substrate is not sanded.

[0082] Example 9:

[0083] Example 9 is basically the same as Example 1, except that in step (2), the ceramic fiber cloth is not subjected to plasma treatment.

[0084] Comparative Example 1:

[0085] (1) Provide a polymer base (polycarbonate);

[0086] (2) Ceramic powder (alumina powder), adhesive (epoxy resin) and water are mixed in a mass ratio of 4:1:3 to obtain a mixed solution. The mixed solution is sprayed onto the surface of the polymer substrate at room temperature (25°C). After drying at room temperature (25°C) for 24 hours, the polymer substrate is placed in a mold and dried and cured in an oven at 150°C for 2 hours to enhance the bonding force between the polymer substrate and the inorganic coating.

[0087] Comparative Example 2:

[0088] Comparative Example 2 is basically the same as Comparative Example 1, except that in step (1), it also includes: using argon as the reactive gas to perform surface plasma treatment on the polymer substrate for 5 minutes.

[0089] The interfacial bonding strength between the polymer substrate and the inorganic coating in the novel composite materials obtained in Examples 1 to 9 and Comparative Examples 1 to 2 was tested, and the test results are shown in Table 1.

[0090] Test method: Interface bonding strength test: Prepare a testable bonding sample according to the above method and test the interface bonding force of the bonding sample on a universal testing machine at a speed of 0.2 mm / min.

[0091] Table 1

[0092]

[0093]

[0094] As shown in Table 1, the method of the present invention for composite inorganic coating on the surface of polymer substrate can significantly improve the interfacial bonding force between polymer substrate and inorganic coating. The interfacial bonding force between polymer substrate and inorganic coating is as high as 26-32 MPa, while the interfacial bonding force in the comparative example is only 0.5 MPa. Compared with the comparative example, the interfacial bonding force between polymer substrate and inorganic coating is increased by more than 52 times using the method of the present invention.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for enhancing the adhesion between polymers and inorganic coatings, characterized in that, The method includes the following steps: (1) Provide a polymer substrate; the polymer substrate is a polycarbonate material, a polymethyl methacrylate material, or a polyethylene material; (2) A ceramic fiber cloth is laminated onto the surface of the polymer substrate using an adhesive to obtain a fiber transition layer; the ceramic fiber cloth is at least one of carbon fiber cloth, glass fiber cloth, alumina fiber cloth, high silica fiber cloth, mullite fiber cloth, or zirconium oxide fiber cloth; the areal density of the ceramic fiber cloth is 1.5~4.0 g / cm³. 3 The tensile strength is 100~3000MPa; (3) An inorganic coating is laminated onto the surface of the fiber transition layer to enhance the bonding force between the polymer substrate and the inorganic coating; The inorganic coating is obtained by spraying or brushing a mixed solution containing ceramic powder, adhesive and water onto the surface of the fiber transition layer; the bonding strength of the inorganic coating on the polymer substrate surface is greater than or equal to 25 MPa and less than or equal to 32 MPa.

2. The method according to claim 1, characterized in that, In step (2), Before the composite ceramic fiber cloth is applied to the surface of the polymer substrate, the process further includes an activation treatment of both the polymer substrate and the ceramic fiber cloth.

3. The method according to claim 2, characterized in that, The activation treatment can be plasma treatment, acid / alkali treatment, sandpaper polishing treatment, silane coupling agent treatment, or oxidation treatment.

4. The method according to claim 1, characterized in that, In step (2), The adhesive is at least one of epoxy resin or phenolic resin; and / or The adhesive coating thickness is 0.5~2mm, and the ceramic fiber cloth thickness is 1~3mm.

5. The method according to claim 1, characterized in that, In step (3), The ceramic powder is at least one of alumina powder, titanium dioxide powder, or silicon dioxide powder; the adhesive is at least one of epoxy resin or phenolic resin.

6. The method according to claim 5, characterized in that, In the mixed solution, the mass ratio of ceramic powder, adhesive and water is (3~5):(1~2):(2~4).

7. The method according to claim 1, characterized in that, In step (3), After the inorganic coating is laminated onto the surface of the fiber transition layer, the process further includes a step of curing the polymer substrate as a whole. The curing temperature is 100~200℃, and the curing time is 1.5~2.5h.

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