Corrosion-resistant uv-cured epoxy resin and method of making same

Abstract

The application discloses a kind of corrosion-resistant UV cured epoxy resin and preparation method thereof, belong to epoxy resin technical field, including: nano titanium dioxide pretreatment, composite modifier preparation, preparation of mixed solution, preparation of precursor powder, preparation of modified nano titanium dioxide, take raw material composite and obtain corrosion-resistant UV cured epoxy resin.The UV cured epoxy resin prepared by the application shows good consistency and stability in core mechanical properties such as adhesion, tensile strength and impact strength, can provide solid mechanical support for pipe lining, meet the mechanical bearing requirements of lining material during fluid transportation, avoid problems such as lining breakage and falling caused by insufficient mechanical properties, and ensure normal operation of the pipeline.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of epoxy resins, in particular to a corrosion-resistant UV-cured epoxy resin and a preparation method thereof. BACKGROUND

[0002] In the actual production fields of petroleum, chemical industry, municipal water supply and drainage, etc., pipelines are the core facilities for fluid transportation, and the transportation medium often presents complex corrosion characteristics. In the field of petroleum and chemical industry, pipelines often need to transport mixed media containing acid, alkali, salt or organic solvent, and some media are accompanied by temperature fluctuations (such as cold and hot alternation during intermittent transportation) and pressure changes. In the field of municipal water supply and drainage, especially in the field of industrial wastewater transportation pipeline or municipal pipeline in coastal areas, the medium not only contains industrial pollutants, but also may mix strong corrosive ions such as chloride ions. Underground pipelines also need to be in contact with moist components and corrosive minerals in the soil for a long time.

[0003] The pipeline lining needs to withstand the continuous action of corrosive media for a long time, and the existing materials are prone to performance degradation after long-term contact. For example, in the petroleum and chemical pipeline, the lining may gradually lose its original structural stability due to medium erosion, and small cracks or local bubbles may occur. These defects will become a channel for the penetration of corrosive media, thereby accelerating the corrosion of the inner wall of the pipeline and shortening the overall service life of the pipeline. In the municipal wastewater pipeline, the lining may be affected by the long-term action of pollutants and chloride ions, resulting in a decrease in adhesion and surface peeling. Not only does it lose its protective effect on the pipeline, but it may also contaminate the transported medium due to the shedding of the lining, affecting water quality safety.

[0004] Therefore, the application designs a corrosion-resistant UV-cured epoxy resin and a preparation method thereof to solve the above problems. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the application provides a preparation method of a corrosion-resistant UV-cured epoxy resin, comprising the following steps:

[0006] S1: nano-titanium dioxide pretreatment, nano-titanium dioxide powder is added into a mixed solvent A of anhydrous ethanol and deionized water, and a suspension is obtained after stirring and ultrasonic dispersion;

[0007] The pH value of the suspension is adjusted to 2.0-3.0, the solid product is collected by centrifugation, and the pretreated nano-titanium dioxide powder is obtained by drying and grinding and sieving;

[0008] S2: preparation of a composite modifier, a silane coupling agent is weighed at 5-8% of the mass of the nano-titanium dioxide powder, and dopamine is weighed at 2-4% of the mass of the nano-titanium dioxide powder, and then they are added into a mixed solvent B, the pH value is adjusted to 10-11, and stirring is performed to obtain a composite modifier solution;

[0009] S3: The pretreated nano-titanium dioxide powder is added to the composite modifier solution at a mass-volume ratio of 1 g:10-20 mL, stirred for 2-4 h at a pH value of 8.0-9.0, and a mixed solution is obtained;

[0010] S4: The mixed solution is centrifuged, and the solid product is collected, washed and dried alternately with anhydrous ethanol and deionized water, and a precursor powder is obtained;

[0011] S5: Low-temperature calcination and solidification, the precursor powder is heated to 220-250℃ under an argon atmosphere, and after being kept for 2-4 h, it is naturally cooled to room temperature, and a modified nano-titanium dioxide is obtained;

[0012] S6: The raw materials are weighed, 38-45 parts of epoxy resin, 6-7.5 parts of emulsifier, 19-25 parts of methacrylic acid, 0.04-0.1 parts of tributyl phosphine, 0.04-0.1 parts of p-hydroxyanisole, 1.2-3.2 parts of dimethyl maleic anhydride, and 0.6-1.2 parts of modified nano-titanium dioxide are weighed;

[0013] S7: Bisphenol A epoxy resin is added to the reaction kettle, and the temperature is raised to 60-70℃ while stirring, p-hydroxyanisole is added and stirred, emulsifier is added, the temperature is raised to 80-90℃ and stirred, pre-mixed tributyl phosphine and methacrylic acid are added dropwise, the temperature is raised to 100-110℃ after the dropwise addition is completed, and the mixture is kept stirring, pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide are added, and the mixture is stirred to obtain a corrosion-resistant UV-curable epoxy resin.

[0014] Further, S1 specifically is: nano-titanium dioxide powder is added to a mixed solvent A of anhydrous ethanol and deionized water at a volume ratio of 7-10:1, wherein the total mass of the mixed solvent A is 10-20 times the mass of the nano-titanium dioxide, and after stirring at 500-600 r / min for 20-30 min, ultrasonic dispersion is performed at 200-400 W for 5-10 min, and a suspension is obtained;

[0015] The pH value of the suspension is adjusted to 2.0-3.0 with 0.1 mol / L hydrochloric acid, and the solid product is collected after centrifugation at 6000-8000 r / min for 10-15 min;

[0016] The solid product is transferred to a vacuum drying oven at 60-80℃ and dried for 12-24 h, ground and sieved through a 200-300 mesh sieve, and a pretreated nano-titanium dioxide powder is obtained.

[0017] Further, S2 is specifically as follows: silane coupling agent is weighed according to 5-8% of the mass of the nano-titanium dioxide powder, dopamine is weighed according to 2-4% of the mass of the nano-titanium dioxide powder, and then the two are added into mixed solvent B at 20-30 DEG C, wherein the volume ratio of ethanol to deionized water in the mixed solvent B is 5-8:1, the total amount of the mixed solvent B is 30-50 times of the total mass of the dopamine and the silane coupling agent, ammonia water is used to adjust the pH value of the solution to 10-11, and the solution is stirred at 40-50 DEG C for 2-3 h to obtain a composite modifier solution.

[0018] Further, S3 is specifically as follows: the pretreated nano-titanium dioxide powder is added into the composite modifier solution according to a mass-volume ratio of 1g:10-20mL, and then the mixture is stirred at 200-300r / min at 50-70 DEG C for 2-4 h, and the pH value is maintained at 8.0-9.0 by adding ammonia water dropwise during the reaction to obtain a mixed solution.

[0019] Further, S4 is specifically as follows: the mixed solution is centrifuged at 8000-10000r / min for 10-15 min, the solid product is collected, and then the solid product is washed with anhydrous ethanol and deionized water alternately for 3-5 times, and then the solid product is placed in a vacuum drying box at 60-80 DEG C for drying for 12-24 h to obtain a precursor powder.

[0020] Further, S5 is specifically as follows: the precursor powder is transferred into a muffle furnace, and then the precursor powder is heated to 220-250 DEG C at a heating rate of 5-10 DEG C / min under an argon atmosphere, and then the precursor powder is naturally cooled to room temperature after being kept at 220-250 DEG C for 2-4 h to obtain modified nano-titanium dioxide.

[0021] Further, S7 is specifically as follows: the bisphenol A epoxy resin is added into a reaction kettle, and then the mixture is stirred at 200-300r / min while being heated to 60-70 DEG C at a heating rate of 15-18 DEG C / h, the mixture is stirred for 5-8 min, the p-hydroxyanisole is added, the mixture is stirred for 3-4 min, the emulsifier is added, the mixture is heated to 80-90 DEG C, the mixture is stirred for 15-20 min, the pre-mixed tributyl phosphine and methacrylic acid are added dropwise at a rate of 0.5-1 part / min, the temperature is increased to 100-110 DEG C after the dropwise addition is completed, the mixture is kept at 100-110 DEG C and stirred for 1-1.5 h, the pre-mixed dimethyl maleic anhydride and the modified nano-titanium dioxide are added, and then the mixture is stirred at 500-600r / min for 30-40 min to obtain the corrosion-resistant UV-cured epoxy resin.

[0022] A corrosion-resistant UV-cured epoxy resin prepared according to the preparation method of the corrosion-resistant UV-cured epoxy resin.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1. The UV-cured epoxy resin prepared by this invention exhibits good consistency and stability in core mechanical properties such as adhesion, tensile strength, and impact strength. It can provide solid mechanical support for pipeline linings, meet the mechanical load-bearing requirements of pipeline lining materials during fluid transportation, avoid problems such as lining damage and detachment due to insufficient mechanical properties, and ensure normal pipeline operation.

[0025] 2. Even after prolonged contact with corrosive media, this invention can still retain its core performance and has excellent corrosion resistance. It can effectively resist the erosion of corrosive components in the pipeline transport medium, slow down the corrosion damage rate of the pipeline inner wall, extend the overall service life of the pipeline, and reduce the probability of safety hazards such as leakage caused by pipeline corrosion. It provides a reliable guarantee for the safe transportation of pipelines in the petroleum, chemical, and municipal fields.

[0026] 3. This invention pretreats nano-titanium dioxide and modifies it using a composite modifier consisting of silane coupling agent and dopamine, combined with a low-temperature calcination process. This effectively solves the problems of easy agglomeration, uneven dispersion, and weak interfacial bonding between traditional nanofillers and the matrix in the resin matrix. This allows nano-titanium dioxide to be more uniformly dispersed in the epoxy resin matrix and form a stable bond with the matrix, further improving the overall performance of the material and avoiding material performance fluctuations or defects caused by filler dispersion problems. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0028] Fig. 1 The infrared spectrum of unmodified nano-titanium dioxide in Example 3;

[0029] Fig. 2 The image shows the infrared spectrum of the modified nano-titanium dioxide prepared in Example 3. 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 only some, not all, of the embodiments of the present invention. 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] Example 1: This embodiment provides a corrosion-resistant UV-cured epoxy resin, comprising, by weight parts:

[0032] 38 parts of epoxy resin (purchased from Dacheng County Minghui Anti-corrosion Material Co., Ltd., bisphenol A epoxy resin), 6 parts of emulsifier (purchased from Xingtai Xinlanxing Technology Co., Ltd., model emulsifier NP-4), 19 parts of methacrylic acid (purchased from Shandong Kejian Chemical Co., Ltd., CAS No. 79-41-4), 0.04 parts of tributyl phosphine (purchased from Shandong Xuchun Chemical Technology Co., Ltd., CAS No. 998-40-3), 0.04 parts of p-hydroxyanisole (purchased from Shandong Yukang Chemical Co., Ltd., CAS No. 150-76-5), 1.2 parts of dimethyl maleic anhydride (purchased from Wuhan Huaxiang Kejie Biological Technology Co., Ltd., CAS No. 766-39-2), 0.6 parts of modified nano-titanium dioxide;

[0033] A preparation method of the corrosion-resistant UV-cured epoxy resin, comprising the following steps:

[0034] S1: Nano-titanium dioxide pretreatment, nano-titanium dioxide powder (purchased from Shanghai Yingfeng Xueliang Metal Material Co., Ltd., model 6320) is added into a mixed solvent A of anhydrous ethanol and deionized water with a volume ratio of 7:1, wherein the total mass of the mixed solvent A is 10 times the mass of the nano-titanium dioxide, after stirring at 500 r / min for 20 min, ultrasonic dispersion is carried out at 200 W for 5 min to obtain a suspension;

[0035] The pH value of the suspension is adjusted to 2.0 with 0.1 mol / L hydrochloric acid, and centrifugation is carried out at 6000 r / min for 10 min, and the solid product is collected;

[0036] The solid product is transferred to a 60℃ vacuum drying oven and dried for 12h, ground and sieved through a 200 mesh sieve to obtain pretreated nano-titanium dioxide powder;

[0037] S2: Preparation of composite modifier, silane coupling agent (A-151) is weighed at 5% of the mass of the nano-titanium dioxide powder, and dopamine is weighed at 2% of the mass of the nano-titanium dioxide powder, which are then added together into a mixed solvent B at 20℃, wherein the volume ratio of ethanol to deionized water in the mixed solvent B is 5:1, and the total amount of the mixed solvent B is 30 times the total mass of the dopamine and the silane coupling agent, the solution pH value is adjusted to 10 with ammonia water, and stirring is carried out at 40℃ for 2h to obtain a composite modifier solution;

[0038] S3: The pretreated nano-titanium dioxide powder is added into the composite modifier solution at a mass-volume ratio of 1g:10mL, and stirring is carried out at 50℃ at 200 r / min for 2h, and the pH value is maintained at 8.0 by adding ammonia water dropwise during the reaction to obtain a mixed solution;

[0039] S4: centrifuge the mixed solution at 8000 r / min for 10 min, collect the solid product, wash it with anhydrous ethanol and deionized water alternately for 3 times, and place it in a 60°C vacuum drying box for drying for 12 h to obtain a precursor powder;

[0040] S5: low-temperature calcination and solidification, transfer the precursor powder into a muffle furnace, heat it to 220°C at a heating rate of 5°C / min under an argon atmosphere, keep it at 220°C for 2 h, and then naturally cool it to room temperature to obtain modified nano-titanium dioxide;

[0041] S6: add bisphenol A epoxy resin into a reaction kettle, heat it to 60°C at a rate of 15°C / h under stirring at 200 r / min, stir for 5 min, add p-hydroxyanisole, stir for 3 min, add an emulsifier, heat it to 80°C, stir for 15 min, add pre-mixed tributyl phosphine and methacrylic acid at a rate of 0.5 parts / min, heat it to 100°C after the addition is completed, keep it at 100°C for 1 h, add pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide, and stir for 30 min at 500 r / min to obtain a corrosion-resistant UV-cured epoxy resin.

[0042] Example 2: The present example provides a corrosion-resistant UV-cured epoxy resin, which comprises, by weight parts:

[0043] 38-45 parts of epoxy resin, 6-7.5 parts of emulsifier, 19-25 parts of methacrylic acid, 0.04-0.1 parts of tributyl phosphine, 0.04-0.1 parts of p-hydroxyanisole, 1.2-3.2 parts of dimethyl maleic anhydride, and 0.6-1.2 parts of modified nano-titanium dioxide;

[0044] A preparation method of the corrosion-resistant UV-cured epoxy resin, comprising the following steps:

[0045] S1: nano-titanium dioxide pretreatment, add nano-titanium dioxide powder into a mixed solvent A of anhydrous ethanol and deionized water in a volume ratio of 10:1, wherein the total mass of the mixed solvent A is 20 times the mass of the nano-titanium dioxide, stir at 600 r / min for 30 min, and then ultrasonically disperse at 400 W for 10 min to obtain a suspension;

[0046] Adjust the pH value of the suspension to 3.0 with hydrochloric acid with a concentration of 0.1 mol / L, centrifuge at 8000 r / min for 15 min, and collect the solid product;

[0047] Transfer the solid product to an 80°C vacuum drying box for drying for 24 h, grind it, and then pass it through a 300-mesh sieve to obtain a pretreated nano-titanium dioxide powder;

[0048] S2: The composite modifier is prepared. The silane coupling agent (A-151) is weighed at 8% of the mass of the nano-titanium dioxide powder, and the dopamine is weighed at 4% of the mass of the nano-titanium dioxide powder. The two are added into the mixed solvent B at 30°C, wherein the volume ratio of ethanol to deionized water in the mixed solvent B is 8:1, the total amount of the mixed solvent B is 50 times the total mass of the dopamine and the silane coupling agent, the pH value of the solution is adjusted to 11 with ammonia water, and the solution is stirred at 50°C for 3 hours to obtain a composite modifier solution;

[0049] S3: The pretreated nano-titanium dioxide powder is added into the composite modifier solution at a mass-volume ratio of 1g:20mL, and stirred at 300r / min at 70°C for 4 hours. The pH value is maintained at 9.0 by adding ammonia water dropwise during the reaction to obtain a mixed solution;

[0050] S4: The mixed solution is centrifuged at 10000r / min for 15min, and the solid product is collected. The solid product is washed with anhydrous ethanol and deionized water alternately for 5 times, and dried in a vacuum drying box at 80°C for 24 hours to obtain a precursor powder;

[0051] S5: Low-temperature calcination and solidification. The precursor powder is transferred into a muffle furnace, and heated to 250°C at a heating rate of 10°C / min under an argon atmosphere. After being kept at 250°C for 4 hours, it is naturally cooled to room temperature to obtain modified nano-titanium dioxide;

[0052] S6: The bisphenol A epoxy resin is added into a reaction kettle, and stirred at 300r / min while heating to 70°C at a rate of 18°C / h. After stirring for 8min, the p-hydroxyanisole is added, and stirred for 4min. The emulsifier is added, and heated to 90°C. After stirring for 20min, the pre-mixed tributylphosphine and methacrylic acid are added dropwise at a rate of 1 part / min. After the dropwise addition is completed, the temperature is raised to 110°C, and the mixture is stirred for 1.5h. The pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide are added, and stirred at 600r / min for 40min to obtain a corrosion-resistant UV-cured epoxy resin.

[0053] Example 3: A corrosion-resistant UV-cured epoxy resin is provided, which comprises, by weight:

[0054] 42 parts of epoxy resin, 7 parts of emulsifier, 22 parts of methacrylic acid, 0.08 parts of tributylphosphine, 0.06 parts of p-hydroxyanisole, 2.5 parts of dimethyl maleic anhydride, and 0.9 parts of modified nano-titanium dioxide;

[0055] A preparation method of the corrosion-resistant UV-cured epoxy resin comprises the following steps:

[0056] S1: Nano-titanium dioxide pretreatment, nano-titanium dioxide powder was added to mixed solvent A of anhydrous ethanol and deionized water in a volume ratio of 8:1, wherein the total mass of mixed solvent A was 15 times the mass of nano-titanium dioxide, stirred at 580 r / min for 25 min, and then ultrasonically dispersed at 350 W for 8 min to obtain a suspension;

[0057] The pH value of the suspension was adjusted to 3.0 with 0.1 mol / L hydrochloric acid, and the solid product was collected by centrifugation at 7000 r / min for 12 min;

[0058] The solid product was transferred to a vacuum drying oven at 75℃ and dried for 18 h, ground and sieved through a 250 mesh sieve to obtain pretreated nano-titanium dioxide powder;

[0059] S2: Preparation of composite modifier, silane coupling agent (A-151) was weighed at 5-8% of the mass of nano-titanium dioxide powder, and dopamine was weighed at 3% of the mass of nano-titanium dioxide powder, which was then added to mixed solvent B at 26℃, wherein the volume ratio of ethanol to deionized water in mixed solvent B was 7:1, and the total amount of mixed solvent B was 45 times the total mass of dopamine and silane coupling agent, and the pH value of the solution was adjusted to 11 with ammonia water, and stirred at 48℃ for 2 h to obtain a composite modifier solution;

[0060] S3: The pretreated nano-titanium dioxide powder was added to the composite modifier solution at a mass volume ratio of 1 g:16 mL, and stirred at 65℃ at 270 r / min for 3 h, and the pH value was maintained at 8.0 by adding ammonia water during the reaction to obtain a mixed solution;

[0061] S4: The mixed solution was centrifuged at 9500 r / min for 14 min, and the solid product was collected and washed with anhydrous ethanol and deionized water alternately for 4 times, and then placed in a vacuum drying oven at 75℃ and dried for 20 h to obtain a precursor powder;

[0062] S5: Low-temperature calcination and solidification, the precursor powder was transferred into a muffle furnace, and the temperature was raised to 240℃ at a rate of 8℃ / min under an argon atmosphere, and then naturally cooled to room temperature after holding for 3 h to obtain modified nano-titanium dioxide;

[0063] S6: Bisphenol A epoxy resin was added to the reaction kettle, and the temperature was raised to 65℃ at a rate of 16℃ / h while stirring at 260 r / min, and then stirred for 7 min, p-hydroxyanisole was added, stirred for 3 min, emulsifier was added, the temperature was raised to 86℃, and stirred for 17 min, and then pre-mixed tributyl phosphine and methacrylic acid were added at a rate of 0.8 parts / min, the temperature was raised to 108℃ after the addition was completed, and stirred for 1.1 h, pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide were added, and stirred at 540 r / min for 37 min to obtain a corrosion-resistant UV-curable epoxy resin.

[0064] Embodiment 4: The embodiment provides a corrosion-resistant UV-cured epoxy resin, comprising, by weight parts:

[0065] 40 parts of epoxy resin, 6.5 parts of emulsifier, 23 parts of methacrylic acid, 0.07 parts of tributyl phosphine, 0.08 parts of p-hydroxyanisole, 2.8 parts of dimethyl maleic anhydride, 1 part of modified nano-titanium dioxide;

[0066] A preparation method of the corrosion-resistant UV-cured epoxy resin, comprising the following steps:

[0067] S1: Nano-titanium dioxide pretreatment, nano-titanium dioxide powder is added into mixed solvent A with a volume ratio of 9:1 of anhydrous ethanol and deionized water, wherein the total mass of the mixed solvent A is 18 times the mass of the nano-titanium dioxide, after stirring at 560 r / min for 23 min, ultrasonic dispersion is carried out at 380 W for 7 min to obtain a suspension;

[0068] The pH value of the suspension is adjusted to 2.0 by using hydrochloric acid with a concentration of 0.1 mol / L, and centrifugation is carried out at 7200 r / min for 14 min, and the solid product is collected;

[0069] The solid product is transferred to a vacuum drying box at 78°C and dried for 20 h, ground and sieved through a 270-mesh screen to obtain pretreated nano-titanium dioxide powder;

[0070] S2: Preparation of a composite modifier, silane coupling agent (A-151) is weighed at 5-8% of the mass of the nano-titanium dioxide powder, and dopamine is weighed at 2% of the mass of the nano-titanium dioxide powder, which are then added together into mixed solvent B at 28°C, wherein the volume ratio of ethanol to deionized water in the mixed solvent B is 6:1, and the total amount of the mixed solvent B is 48 times the total mass of the dopamine and the silane coupling agent, and the pH value of the solution is adjusted to 10 by using ammonia water, and stirring is carried out at 46°C for 2.5 h to obtain a composite modifier solution;

[0071] S3: The pretreated nano-titanium dioxide powder is added into the composite modifier solution at a mass-volume ratio of 1 g:10-20 mL, and stirring is carried out at 67°C at 290 r / min for 2.5 h, and the pH value is maintained at 9.0 by dropwise adding ammonia water during the reaction to obtain a mixed solution;

[0072] S4: The mixed solution is centrifuged at 8500 r / min for 12 min, and the solid product is collected, washed with anhydrous ethanol and deionized water alternately for 3 times, and placed in a vacuum drying box at 78°C for 18 h to obtain a precursor powder;

[0073] S5: low-temperature calcination solidification, the precursor powder was transferred into a muffle furnace, and the temperature was raised to 230℃ at a rate of 7℃ / min under an argon atmosphere, and after holding for 3.5h, it was naturally cooled to room temperature to obtain modified nano-titanium dioxide;

[0074] S6: The reaction kettle was added with bisphenol A epoxy resin, and the temperature was raised to 67℃ at a rate of 17℃ / h under stirring at 280r / min, and after stirring for 8min, p-hydroxyanisole was added, and after stirring for 3min, an emulsifier was added, and the temperature was raised to 88℃, and after stirring for 19min, the pre-mixed tributyl phosphine and methacrylic acid were added dropwise at a rate of 0.6 parts / min, and after the dropwise addition was completed, the temperature was raised to 105℃, and after holding and stirring for 1.5h, the pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide were added, and after stirring for 35min at 560r / min, a corrosion-resistant UV-curable epoxy resin was obtained.

[0075] Comparative Example 1: The difference between this comparative example and Example 3 is that the nano-titanium dioxide is not pretreated.

[0076] Comparative Example 2: The difference between this comparative example and Example 3 is that dopamine is not added in S2.

[0077] Comparative Example 3: The difference between this comparative example and Example 3 is that the untreated nano-titanium dioxide powder is directly used.

[0078] Infrared characterization experiment of nano-titanium dioxide;

[0079] Infrared characterization of nano-titanium dioxide before and after modification in Example 3 was performed as follows:

[0080] The nano-titanium dioxide powder (purchased from Shanghai Yingfeng Xuelang Metal Material Co., Ltd., grade 6320) was directly mixed with dry KBr powder at a ratio of about 1:100, ground uniformly, and pressed into a transparent wafer; a Fourier transform infrared spectrometer (FTIR) was used, with a resolution of 4cm -1 , and a scanning range of 4000-400cm -1 , and a blank KBr background spectrum was collected before testing.

[0081] As can be seen from Figs. 1-2 , the modified nano-titanium dioxide has a Ti-O-Si peak (900-1000cm -1 ) in the infrared spectrum, and the 3514 (superimposed N-H) / 1621 (superimposed benzene ring) peak is widened, verifying that the nano-titanium dioxide is successfully modified.

[0082] Experimental Example 1: Adhesion test (pull-off method);

[0083] For sample preparation, Q235 steel plates were cut into 100mm×100mm×3mm test plates. After removing the edge burrs with an angle grinder, the plates were sandblasted with 1.2mm quartz sand. The compressed air pressure was controlled at 0.6MPa and the sandblasting distance was 200mm. After sandblasting, the surface was wiped with degreased cotton soaked in anhydrous ethanol to remove dust. The plates were then placed in a silica gel desiccator for later use. The coating process should be completed within 2 hours to avoid secondary contamination.

[0084] During coating preparation, the corrosion-resistant UV-curable epoxy resin of this invention was stirred evenly and then coated onto the surface of the test panel using a wet film preparation device, controlling the wet film thickness to 120 μm. Subsequently, a UV curing machine with a wavelength of 365 nm and a power of 80 W / cm was used to irradiate the coating surface at a distance of 15 cm for 60 seconds. After curing, the test panel was cured in an environment of 25°C and 50%RH for 24 hours and marked as uncorroded (3 parallel samples per group). Another 3 test panels from the same batch were prepared according to the same procedure and marked as corroded (3 parallel samples per group).

[0085] The corrosion treatment employed a neutral salt spray test using a salt spray test chamber. The salt solution was prepared by dissolving 500g of NaCl in 9500mL of deionized water, stirring until completely dissolved, and then adjusting the pH to 7.2 with 0.1mol / L HCl. The test chamber parameters were set as follows: temperature 35℃, relative humidity >95%, and salt spray deposition rate 2.0mL / (h・80cm). 2 Spray continuously for 500 hours. Place the corrosion sample horizontally on the middle partition in the chamber with the coating facing up. The spacing between samples should be ≥20mm to avoid cross-contamination. After 500 hours, take it out and rinse it with 40℃ deionized water for 1 minute to remove residual salt. After absorbing the moisture with a lint-free cloth, dry it in an environment of 25℃ and 50%RH for 24 hours.

[0086] Mix the epoxy resin and ethylenediamine curing agent of this invention at a mass ratio of 10:1, stir for 1 minute until uniform, and let stand in the dark for 5 minutes to eliminate air bubbles. Use a microsyringe to take 0.1 mL of adhesive and apply it evenly to the bottom surface of a 20 mm diameter steel test column. Align the center of the test column with the center point of the coating surface and press to spread the adhesive evenly. Use clamps to fix the test column and test plate to prevent displacement. Let stand in an environment of 25°C and 50%RH for 24 hours until the adhesive is completely cured.

[0087] Preheat the tensile testing machine for 30 minutes. Fix the test plate in the lower clamp of the testing machine (ensure it is horizontal). Connect the top thread of the test column to the upper clamp. Adjust the clamp so that the direction of the tensile force is completely aligned with the axis of the test column (avoid eccentric force). Stretch at a uniform speed of 1 mm / min and record the tensile force value in real time until the coating is damaged. Record the maximum tensile force F. If the damaged area is ≥90%, it indicates damage at the interface between the coating and the substrate, and the result is valid. If the damage is at the interface between the test column and the adhesive, the test needs to be re-bonded and tested.

[0088] Results were calculated as the adhesion force of a single sample:

[0089]

[0090] Unit: MPa, 3 parallel samples were taken to calculate the arithmetic mean.

[0091] Experimental Example 2: Tensile strength test (MPa);

[0092] A dumbbell mold of type I was used, with a total length of 115 mm, a parallel portion length of 50 mm, a width of 10 mm, a thickness of 4 mm, and a clamping portion width of 25 mm at both ends. After wiping the mold cavity with anhydrous ethanol, a spray-type release agent was sprayed, and it was dried at room temperature for 10 min;

[0093] The corrosion-resistant UV-cured epoxy resin of the present application was degassed using a vacuum degassing machine (-0.1 MPa, 2 min) to remove bubbles, then the material was slowly poured into the mold cavity, and the surface was scraped flat with a scraper (to avoid bubbles). The material that overflowed the edges of the mold was cut off. The same UV parameters as in Experimental Example 1 were used for curing, and after curing, the samples were left to stand for 5 min. The samples were gently pried out along the edges of the mold with tweezers, and the edge burrs were polished with 800-mesh fine sandpaper. The samples were cured in an environment of 25°C and 50% RH for 48 h, and were marked as uncorroded (5 parallel samples per group). Five samples of the same batch were prepared and marked as corroded (5 parallel samples per group);

[0094] The corrosion treatment was the same as in Experimental Example 1;

[0095] The environmental conditions were balanced before testing. The laboratory was maintained at 25°C and 50% RH, and the samples were placed in this environment for 4 h to achieve temperature equilibrium. The universal material testing machine was calibrated with 5kN standard weights, and the tensile rate was set to 50 mm / min, with a clamping distance of 50 mm. During testing, the thickness (d) and width (b) of the parallel portion of the sample were measured with a digital vernier caliper (precision 0.01 mm), and the average value of 3 points was taken (accurate to 0.01 mm). The sample was clamped at both ends in the testing machine clamp, ensuring that the sample axis was aligned with the tensile direction (deviation ≤1°). After starting the testing machine, the real-time tensile force-displacement curve was recorded until the sample broke. The maximum tensile force (F, accurate to 0.1 N) and the breaking position were recorded. If the break occurred in the clamping portion, the result was invalid and needed to be retested.

[0096] Results were calculated as the tensile strength of a single sample:

[0097]

[0098] Unit: MPa, 5 parallel samples were taken to calculate the average value after removing the maximum and minimum values.

[0099] Experimental Example 3: Impact strength test (kg·cm);

[0100] Select 150mm x 70mm x 0.3mm tin plate, gently polish the surface with 120# sandpaper to remove the oxide layer, put it into 5% NaOH solution, ultrasonic cleaning at 60°C for 5min, then take it out and rinse it with deionized water until it is neutral, dehydrate it with anhydrous ethanol, and dry it at room temperature. The treated tin plate needs to be coated within 2h to avoid rusting;

[0101] The corrosion-resistant UV-cured epoxy resin of the application was coated on the surface of the tin plate with RDS5# wire bar coater, and the wet film thickness was controlled at 60μm. The same UV curing as in Experimental Example 1-2 was used. After curing, the samples were cured in an environment of 25°C and 50% RH for 24h, marked as uncorroded (5 parallel samples per group), and another 5 samples of the same batch were prepared and marked as corroded, and corroded for 500h according to the salt spray conditions of Experimental Example 1, and then dried for standby;

[0102] The weight of the hammer of the paint film impact tester was weighed with an electronic balance (ensuring the mass to be 1000±1g), the drop hammer height scale was adjusted (accuracy 1cm), the smoothness of the impact head surface was checked (diameter 10±0.1mm), the sample coating was placed flat on the test machine base groove with the coating facing up, and the sample was fixed with a pressing block (ensuring that the sample was not loose and the edge was aligned with the base), the initial test setting was 50cm, the hammer was released to freely fall on the center of the sample (the impact point was 30mm away from the edge of the sample), and the coating was observed with a 4x magnifying lens after impact to see if there were cracks, peeling or bare spots. If there was no damage at 50cm, the height was increased in turn (60cm, 70cm…), until at least 2 of the 3 samples were damaged, and the height (h) at this time was recorded;

[0103] The results were calculated as follows:

[0104]

[0105] Unit kg・cm.

[0106] The results are shown in the following table:

[0107]

[0108] As can be seen from the above table, the corrosion-resistant UV-cured epoxy resin of Examples 1-4 has good consistency in terms of adhesion, tensile strength and impact strength before corrosion, indicating that the basic mechanical properties of the material are controllable, the overall quality is stable, and the retention rate of these mechanical properties remains at a high level after corrosion treatment, indicating that the combination of nano-titanium dioxide pretreatment, composite modification and low-temperature calcination processes used in the examples can effectively improve the resistance of the material to corrosive media, so that the material can still maintain good core mechanical properties after long-term contact with corrosive environments, meeting the dual requirements of mechanical support and corrosion resistance of pipe lining materials.

[0109] The comparative example 1 has a gap in mechanical properties and corrosion retention rate with the examples because it is not pre-treated with nano-titanium dioxide, which shows that the pre-treatment step (including solvent dispersion, pH adjustment, centrifugal drying, etc.) can optimize the surface state of nano-titanium dioxide, lay a foundation for subsequent composite modification, and further help to improve the overall performance of the material;

[0110] The comparative example 2 has a weaker performance than the examples because it does not add dopamine during the preparation of the composite modifier, which reflects the synergistic effect of dopamine and silane coupling agent. Dopamine can assist in enhancing the binding effect of nano-titanium dioxide and the modifier, further improving the compatibility of nano-filler and epoxy resin matrix, and providing important support for the improvement of mechanical properties and corrosion resistance of the material.

[0111] The comparative example 3 directly uses untreated nano-titanium dioxide powder, and its mechanical properties and corrosion retention rate are relatively backward among all test samples, which proves that the nano-titanium dioxide that is not pre-treated and modified is difficult to form a stable combination with the resin matrix, which is easy to cause defects in the internal structure of the material, and further affect the mechanical properties and corrosion stability of the material.

[0112] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a corrosion resistant UV-cured epoxy resin, characterized by, Comprising the following steps: S1: nano-titanium dioxide pretreatment: nano-titanium dioxide powder is added to anhydrous ethanol and deionized water mixed solvent A, and after stirring, a suspension is obtained by ultrasonic dispersion; The pH value of the suspension is adjusted to 2.0-3.0, the solid product is collected by centrifugation, and the pretreated nano-titanium dioxide powder is obtained by drying and grinding and sieving; S2: preparation of composite modifier: silane coupling agent is weighed at 5-8% of the mass of nano-titanium dioxide powder, and dopamine is weighed at 2-4% of the mass of nano-titanium dioxide powder, and then added together into mixed solvent B, and the pH value is adjusted to 10-11, and stirred to obtain a composite modifier solution, wherein the volume ratio of ethanol to deionized water in the mixed solvent B is 5-8:1; S3: The pretreated nano-titanium dioxide powder is added to the composite modifier solution at a mass-volume ratio of 1g:10-20mL, and stirred at a pH value of 8.0-9.0 for 2-4h to obtain a mixed solution; S4: The mixed solution is centrifuged, and the solid product is collected, washed with anhydrous ethanol and deionized water, and dried to obtain a precursor powder; S5: low-temperature calcination and solidification: the precursor powder is heated to 220-250℃ under argon atmosphere, and after holding for 2-4h, it is naturally cooled to room temperature to obtain modified nano-titanium dioxide; S6: weighing raw materials: 38-45 parts of bisphenol A epoxy resin, 6-7.5 parts of emulsifier, 19-25 parts of methacrylic acid, 0.04-0.1 parts of tributyl phosphine, 0.04-0.1 parts of p-hydroxyanisole, 1.2-3.2 parts of dimethyl maleic anhydride, and 0.6-1.2 parts of modified nano-titanium dioxide; S7: add bisphenol A epoxy resin to the reaction kettle, and heat to 60-70℃ while stirring, add p-hydroxyanisole and stir, add emulsifier, heat to 80-90℃ and stir, add pre-mixed tributyl phosphine and methacrylic acid dropwise, after dropwise addition is completed, heat to 100-110℃, hold and stir, add pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide, and stir to obtain a corrosion-resistant UV-curable epoxy resin.

2. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S1 is specifically: nano-titanium dioxide powder is added to anhydrous ethanol and deionized water mixed solvent A with a volume ratio of 7-10:1, wherein the total mass of the mixed solvent A is 10-20 times the mass of the nano-titanium dioxide, and after stirring at 500-600r / min for 20-30min, ultrasonic dispersion is carried out at 200-400W for 5-10min to obtain a suspension; The pH value of the suspension is adjusted to 2.0-3.0 with 0.1mol / L hydrochloric acid, and the solid product is collected by centrifugation at 6000-8000r / min for 10-15min; The solid product is transferred to a vacuum drying oven at 60-80℃ and dried for 12-24h, ground and sieved through a 200-300 mesh sieve to obtain pretreated nano-titanium dioxide powder.

3. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S2 specifically is: silane coupling agent is weighed according to 5-8% of the mass of nano-titanium dioxide powder, dopamine is weighed according to 2-4% of the mass of nano-titanium dioxide powder, at 20-30 DEG C, they are added into mixed solvent B together, wherein the total amount of mixed solvent B is 30-50 times of the total mass of dopamine and silane coupling agent, ammonia water is used to adjust the pH value of the solution to 10-11, stirring is carried out at 40-50 DEG C for 2-3 h, and a composite modifier solution is obtained.

4. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S3 specifically is: the pretreated nano-titanium dioxide powder is added into the composite modifier solution according to the mass-volume ratio of 1g:10-20 mL, stirring is carried out at 200-300 r / min at 50-70 DEG C for 2-4 h, and the pH value is maintained at 8.0-9.0 by adding ammonia water dropwise during the reaction, and a mixed solution is obtained.

5. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S4 specifically is: the mixed solution is centrifuged at 8000-10000 r / min for 10-15 min, the solid product is collected, washed with anhydrous ethanol and deionized water alternately for 3-5 times, and placed in a vacuum drying oven at 60-80 DEG C for drying for 12-24 h, and a precursor powder is obtained.

6. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S5 specifically is: low-temperature calcination solidification, the precursor powder is transferred into a muffle furnace, the temperature is raised to 220-250 DEG C at the heating rate of 5-10 DEG C / min under argon atmosphere, and after heat preservation for 2-4 h, it is naturally cooled to room temperature, and modified nano-titanium dioxide is obtained.

7. The method for preparing the corrosion-resistant UV-curable epoxy resin according to claim 1, characterized in that, S7 specifically is: the reaction kettle is added with bisphenol A epoxy resin, the temperature is raised to 60-70 DEG C at the heating rate of 15-18 DEG C / h under stirring at 200-300 r / min, stirring is carried out for 5-8 min, p-hydroxyanisole is added, stirring is carried out for 3-4 min, an emulsifier is added, the temperature is raised to 80-90 DEG C, stirring is carried out for 15-20 min, the pre-mixed tributyl phosphine and methacrylic acid are added dropwise at the rate of 0.5-1 part / min, after the dropwise addition is completed, the temperature is raised to 100-110 DEG C, heat preservation and stirring are carried out for 1-1.5 h, the pre-mixed dimethyl maleic anhydride and modified nano-titanium dioxide are added, and stirring is carried out at 500-600 r / min for 30-40 min, and a corrosion-resistant UV-cured epoxy resin is obtained.

8. A corrosion-resistant UV-cured epoxy resin prepared by the preparation method of the corrosion-resistant UV-cured epoxy resin according to any one of claims 1-7.

Images