A method for preparing a high-toughness IPN long-acting antifouling polyurethane elastomer coating

Abstract

The application discloses a preparation method of high-toughness IPN long-acting antifouling polyurethane elastomer coating, which comprises the following steps: modifying a polymeric guanidine and a polytetrahydrofuran diol-polyurethane matrix resin by using an organic modification method to improve the antifouling capability and toughness of the polyurethane matrix resin, and to provide a plurality of hydroxyl functional groups, thereby improving the adhesion of the coating and a base material; and combining the polymeric guanidine modified polyurethane resin and the polyurethane matrix resin by using a solvent thermal method, and successfully introducing an IPN structure into the polyurethane system, thereby improving the toughness of the whole film layer, optimizing the cavitation erosion resistance of the film layer, and further preparing the high-toughness IPN antifouling polyurethane elastomer coating. The application can effectively reduce the damage of mechanical impact on the coating, prolong the service life, and realize the benefits of energy saving and the like.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, specifically to a method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating. Background Technology

[0002] With the rapid development of the global economy and the increasing frequency of human activities, the marine environment is facing unprecedented challenges. In particular, ships, offshore facilities, and marine engineering structures, which are submerged in seawater for extended periods, are susceptible to biofouling. This not only increases maintenance costs but can also lead to performance degradation and even safety accidents. Therefore, developing efficient marine antifouling coating technologies is of great significance for protecting the marine environment and maintaining the safety of marine facilities. However, as antifouling coatings serve in the complex marine environment for longer periods, cracks inevitably appear on the coating surface. The continuous generation and growth of these cracks not only affect the mechanical properties of the cavitation erosion coating but also cause cracking, crazing, and even large-scale peeling off of the coating.

[0003] In marine antifouling coating research, interpenetrating polymer networks (IPNs) have attracted significant attention due to their unique properties. The introduction of IPN structures can further enhance the original antifouling performance of coatings. Generally, marine antifouling coatings rely on adding antifouling agents to prevent biofouling, but these agents can negatively impact the marine ecosystem and lead to a decline in the coating's own performance. In contrast, IPN structures can achieve long-term, highly efficient antifouling effects through the design of appropriate polymer network structures and components. Furthermore, IPN structures can enhance coating stability. The marine environment is complex and variable, requiring coatings to withstand various factors such as salt spray, tides, and ultraviolet radiation. The interpenetrating and entangled polymer networks of the IPN structure form an "interlocking" structure, which gives the coating higher mechanical and chemical stability. Even in harsh marine environments, IPN structure coatings can maintain their original performance and appearance.

[0004] Existing marine antifouling methods struggle to meet long-term stable performance requirements, primarily due to the following two reasons:

[0005] (1) When the ship is in a static state, the antifouling coating needs to release its own active functional groups to obtain a better antifouling effect. However, this method will severely shorten the service life of the coating and reduce the mechanical properties of the antifouling coating.

[0006] (2) When the vessel is in motion, the low surface energy and self-renewal properties of the coating are usually utilized to prevent fouling organisms from adhering to the coating surface under the shear force of the water flow. This antifouling method is highly dependent on the high speed of the vessel and the mechanical strength of the coating itself, and has many limitations. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention discloses a method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating, thereby solving the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating, comprising the following steps:

[0009] S1. Preparation of polytetrahydrofurandiol-polyurethane matrix;

[0010] Take a dry three-necked flask, add xylene and isophorone diisocyanate in a ratio of n(-NCO / -OH)=2.5, stir and heat to 80℃ with a constant temperature stirrer, continue stirring for 10 min, slowly add a measured amount of polytetrahydrofuran diol within 15 min, continue the reaction at constant temperature for 2 h, and obtain a light yellow oily liquid PTMG-IPDI polyurethane resin (PU).

[0011] S2. Preparation of polymeric guanidine-modified polyurethane resin;

[0012] 1) Take the measured amount of hexamethylenediamine and guanidine hydrochloride and add them to a new dry three-necked flask. Stir the material using the melting heat method and stir the material at 90°C for 2 hours. Then raise the temperature to 160°C and continue stirring for 1 hour to obtain a milky white liquid, thus obtaining polymeric guanidine.

[0013] 2) Then cool down, take the measured PTMG-IPDI polyurethane resin obtained in step S1 and add it to the new three-necked flask. Heat to 80°C and continue stirring for 2 hours to obtain a light yellow semi-transparent polymeric guanidine modified polyurethane resin (GPU).

[0014] S3. Prepare an IPN structured polyurethane film;

[0015] Polyurethane IPN structural elastomer slurry contains three components;

[0016] Component A: PTMG-IPDI polyurethane resin obtained in step S1;

[0017] Component B: Mix 1,4-butanediol (BDO) and 330N in a certain proportion at room temperature until homogeneous, add the catalyst, and then seal and store.

[0018] Component C: Polyguanidine-modified polyurethane resin is obtained through step S2;

[0019] Components A, B, and C were mixed according to their mass fractions and stirred rapidly for 5 minutes. The mixture was then placed under vacuum to remove air bubbles. The mixture was then coated onto a flow-through component preheated to 80°C and cured at that temperature for 10 hours to obtain an IPN structure polyurethane film (IGPU).

[0020] Preferably, in step S1, the xylene is 25% of the total mass of PTMG2000 and IPDI.

[0021] Preferably, in step S2, the mass ratio of the hexamethylenediamine added to guanidine hydrochloride is 5:1.

[0022] Preferably, in step S2, the mass of the added PTMG-IPDI matrix resin is 110g, with a variation range of 80g-150g.

[0023] Preferably, in step S2, PTMG-IPDI polyurethane resin is added to the three-necked flask, heated to 80°C, and stirred continuously. The reaction is considered terminated when the resin changes from milky white to pale yellow and translucent. The reaction time is 1.5h-3h.

[0024] Preferably, in step S3, the three components include the following by mass parts:

[0025] Component A: 100g polyurethane prepolymer resin; 0-20g diluent;

[0026] Component B: Chain extender 330N 0-60; chain extender BDO 0-40; catalyst 0.1-0.5; diluent 0-10;

[0027] Component C: GPU 0-15.

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

[0029] 1. The multifunctional coating of this invention utilizes an organic modification method to functionally modify polymeric guanidine and polytetrahydrofuran diol (PTMG)-polyurethane matrix resin, improving the antifouling ability and toughness of the polyurethane matrix resin and providing multi-hydroxyl functional groups, thereby enhancing the adhesion between the coating and the substrate. Then, a solvothermal method is used to combine the polymeric guanidine-modified polyurethane resin with the polyurethane matrix resin to prepare a high-toughness IPN antifouling polyurethane elastomer coating. The rigid and flexible segments in the polyurethane matrix resin molecular chain used in this invention are interlocked, giving the elastomer both high strength and good flexibility. Under external impact and tension, it can rapidly crystallize and exhibit excellent cavitation erosion resistance.

[0030] 2. In this invention, an interpenetrating network structure is formed by ordinary polyurethane matrix resin and modified antifouling resin. The interpenetrating network structure interweaves the antifouling functional segments and matrix segments to form a stable interlocking structure, ensuring that the film layer has high toughness and long-term antifouling activity. The preparation of the polymeric guanidine modified polyurethane resin can effectively trigger the repulsion effect of fouling organisms, thereby reducing the willingness of fouling organisms to adhere to the film layer surface and playing an antifouling role. The bactericidal ability of guanidine groups can further inhibit the formation of biofilm on the coating surface and enhance the antifouling ability.

[0031] 3. The method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating provided in this invention successfully introduces the IPN structure into the polyurethane system, which improves the toughness of the entire film layer, optimizes the anti-cavitation performance of the film layer, and can effectively reduce the damage of mechanical impact to the coating, extend its service life, and achieve benefits such as energy saving. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0033] In the attached diagram:

[0034] Figure 1 This is a scanned image of a typical microsphere protrusion structure in the coating of this invention;

[0035] Figure 2 This is a scanned image of a typical micro-wrinkle structure of the coating of this invention;

[0036] Figure 3 This is a schematic diagram of the seaweed adhesion density on the surface of each coating of the present invention. Detailed Implementation

[0037] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0038] Example: Figure 1 and Figure 2 As shown, a method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating includes the following steps:

[0039] S1. Add xylene (25% of the total mass of PTMG2000 and IPDI) and 250g of PTMG to a three-necked flask. Stir slowly and heat to 60°C. Continue stirring for 10 minutes. Slowly add the measured amount of IPDI dropwise over 15 minutes. Continue the reaction at a constant temperature for 2 hours and then stop. Determine the reaction endpoint by titration. Control the theoretical NCO content to about 6.5% to obtain a slightly yellow oily liquid PTMG-IPDI matrix resin.

[0040] S2. Add 10g of hexamethylenediamine (HDA) and 2g of guanidine hydrochloride to a three-necked flask, mix thoroughly, heat to 90°C and maintain for 2 hours, then heat to 160°C at a rate of 10°C / min and stir for 1 hour to obtain a milky white liquid polymeric guanidine. Cool the obtained liquid to 60°C, add PTMG-IPDI matrix resin, stir for 1 hour to mix the materials thoroughly, heat to 80°C and stir for 2 hours to obtain a pale yellow, semi-transparent polyguanidine modified matrix resin (GPU).

[0041] S3, polyurethane IPN structural elastomer slurry contains three components:

[0042] Component A: PTMG-IPDI polyurethane resin obtained in step S1;

[0043] Component B: Mix a certain proportion of BDO and 330N evenly at room temperature, add the catalyst, and then seal and store.

[0044] Component C: Polyguanidine-modified polyurethane resin GPU obtained in step S2.

[0045] The three components are as follows by mass:

[0046] Component A: 100g polyurethane prepolymer resin; 10g diluent;

[0047] Component B: Chain extender 330N 20; chain extender BDO 30; catalyst 0.1; diluent 5;

[0048] Component C: GPU 15.

[0049] The three components A, B, and C were mixed according to their mass proportions and stirred rapidly for 5 minutes. The mixture was then placed under vacuum to remove air bubbles. The mixture, which is the high-toughness IPN long-lasting antifouling polyurethane elastomer coating to be prepared, was applied to the flow-through component preheated to 80°C. The mixture was then kept at the temperature and cured for 10 hours to obtain the IPN structure polyurethane film (IGPU).

[0050] Among them, such as Figure 3As shown, the density of algae adhesion on the surface of each coating can be seen. It can be seen that the preparation of the polymer guanidine modified polyurethane resin used in this invention can effectively trigger the repulsion effect of fouling organisms, thereby reducing the willingness of fouling organisms to adhere to the film surface and playing a role in antifouling.

[0051] Further Examples

[0052] In S1, the xylene solvent can be replaced with N,N-dimethylformamide (DMF), the polyether can be replaced with PPG3000, and the isocyanate can be replaced with MDI.

[0053] In S2, the mass ratio of the hexamethylenediamine added to guanidine hydrochloride is 5:1.

[0054] Among them, the ratio of hexamethylenediamine to guanidine hydrochloride is a key technology. The ratio of phytic acid to chitosan is 6:1, 5:1, 3:1, with 5:1 being suitable. The concentration of HDA will reduce the degree of binding between guanidine groups and polyurethane matrix, while too high a concentration will promote excessive cross-linking of polyurethane.

[0055] In S2, the mass of the added PTMG-IPDI matrix resin is 110g, with a variation range of 80g-150g, and the optimal mass is 110g.

[0056] In step S2, PTMG-IPDI polyurethane resin is added to the three-necked flask mentioned above. After heating to 80°C, stirring is continued. The reaction is considered terminated when the resin changes from milky white to a pale yellow semi-transparent state. The reaction time is 1.5h-3h.

[0057] In S3, the range of variation of the proportions of each component is as follows:

[0058] Component A: 100g polyurethane prepolymer resin; 0-20g diluent;

[0059] Component B: Chain extender 330N 0-60; chain extender BDO 0-40; catalyst 0.1-0.5; diluent 0-10;

[0060] Component C: GPU 0-15.

[0061] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for the preparation of high-toughness IPN long-lasting antifouling polyurethane elastomer coating characterized by, Includes the following steps: S1. Preparation of PTMG-IPDI polyurethane resin; Take a dry three-necked flask, add xylene and isophorone diisocyanate in a ratio of n(-NCO / -OH)=2.5, stir and heat to 80°C using a constant temperature stirrer, continue stirring for 10 min, slowly add a measured amount of polytetrahydrofuran diol within 15 min, continue the reaction at a constant temperature for 2 h, and obtain a slightly yellow oily liquid PTMG-IPDI polyurethane resin. S2. Preparation of polymeric guanidine modified polyurethane resin; 1) Take the measured amount of hexamethylenediamine and guanidine hydrochloride and add them to a new dry three-necked flask. Stir the material using the melting heat method and stir the material at 90°C for 2 hours. Then raise the temperature to 160°C and continue stirring for 1 hour to obtain a milky white liquid, thus obtaining polymeric guanidine. 2) Then cool down, take the measured PTMG-IPDI polyurethane resin obtained in step S1 and add it to the new three-necked flask. Heat to 80°C and continue stirring for 2 hours to obtain a light yellow semi-transparent polymeric guanidine modified polyurethane resin. S3. Prepare an IPN structured polyurethane film; Polyurethane IPN structural elastomer slurry contains three components; Component A: PTMG-IPDI polyurethane resin obtained in step S1; Component B: Mix 1,4-butanediol (BDO) and 330N in a certain proportion at room temperature until homogeneous, add catalyst and then seal and store. Component C: Polyguanidine-modified polyurethane resin is obtained through step S2; The three components A, B, and C were mixed according to the mass fractions and stirred rapidly for 5 minutes. The mixture was then placed under vacuum to remove air bubbles. The mixture was then coated onto the flow-through component preheated to 80°C and cured at that temperature for 10 hours to obtain the IPN structure polyurethane film. In step S2, the mass ratio of the hexamethylenediamine added to guanidine hydrochloride is 5:1; In step S2, the mass of the added PTMG-IPDI polyurethane resin is 110g; In step S3, the three components, by mass parts, include the following: Component A: 100g polyurethane prepolymer resin; 10-20g diluent; Component B: Chain extender 330N 20-60; chain extender BDO 30-40; catalyst 0.1-0.5; diluent 5-10; Component C: Polyguanidine modified polyurethane resin 15.

2. The method for preparing a high-toughness IPN long-lasting antifouling polyurethane elastomer coating according to claim 1, characterized in that: In step S1, the xylene is 25% of the total mass of PTMG2000 and IPDI.

Images