Polyurethane foaming process and corrosion-resistant polyurethane material

Abstract

The invention discloses a polyurethane foaming process and a corrosion-resistant polyurethane material, and the process comprises the following steps: providing a polyol component containing fluorinated modified polyether polyol, and mixing the polyol component with a nano graphene oxide filler, an organic phosphine corrosion-resistant additive, water, an amine catalyst and a non-silicon-based surfactant to form a mixture X; the isocyanate component Y is used for providing polyfunctionality and is a prepolymer formed by reacting modified diphenylmethane diisocyanate with a compound containing two or more active hydrogen groups; and mixing the mixture X and an isocyanate component Y according to a mass ratio of 1: 1 to form an active mixture Z, pouring the active mixture Z into a mold for foaming and curing, then taking out the active mixture Z from the mold for heat treatment and surface treatment, and finally obtaining the corrosion-resistant polyurethane product. Through innovative design of material components and process conditions, efficient preparation of the corrosion-resistant polyurethane material is realized, the application requirements in a specific corrosion environment are met, and the corrosion resistance and mechanical properties of the material are improved.

Description

Technical Field

[0001] The invention relates to the field of polyurethane foam, in particular to a polyurethane foaming process and a corrosion-resistant polyurethane material. Background Art

[0002] With the rapid development of the industrial field, polyurethane foam materials are widely used in building insulation, pipeline insulation, cold storage insulation and other fields due to their excellent thermal insulation, heat preservation and lightweight properties. In some special application scenarios, such as chemical plants, sewage treatment plants, mine tunnels, landfills and other environments, these places usually have the characteristics of high humidity, high salinity or the presence of corrosive chemical media, which puts higher requirements on the corrosion resistance of materials. Under these harsh environmental conditions, traditional materials are often difficult to use for a long time, and are prone to aging, cracking, performance degradation and other problems, which affect the normal operation and service life of the equipment. Therefore, it is of great practical significance to develop a corrosion-resistant polyurethane foam material suitable for high humidity and high salinity environments.

[0003] In the prior art, conventional polyether polyols and isocyanate components are usually used to prepare polyurethane foam materials through a foaming process. However, these traditional polyurethane foams are susceptible to erosion by moisture and corrosive media in high humidity and high salinity environments, resulting in the destruction of the foam structure and degradation of material performance. In order to improve corrosion resistance, some technical solutions attempt to add anti-corrosion fillers to the foaming system or apply a protective layer on the surface, but these methods often have problems such as uneven filler dispersion, poor interface compatibility, and complex processing technology. They cannot fundamentally solve the problem of insufficient corrosion resistance of the material, limiting the application of polyurethane foam materials in specific corrosive environments.

[0004] In view of this, it is necessary to improve the preparation technology of polyurethane foam materials in the prior art to solve the technical problem of poor tolerance to external corrosive media. Summary of the invention

[0005] The purpose of the present invention is to provide a polyurethane foaming process and a corrosion-resistant polyurethane material to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions: A polyurethane foaming process, comprising: Step S1, providing a polyol component containing a fluorinated polyether polyol, mixing the polyol component with a nano-graphene oxide filler, an organic phosphine-based preservative, water, an amine catalyst and a non-silicon-based surfactant, and stirring the mixture to form a uniform mixture X; Step S2, providing a multifunctional isocyanate component Y, wherein the isocyanate component Y is a prepolymer formed by reacting modified diphenylmethane diisocyanate with a compound containing two or more active hydrogen groups, so that the compound has a reactivity within a preset range; Step S3, at room temperature, the mixture X and the isocyanate component Y are rapidly mixed in a mass ratio of 1:1, and high-speed stirring is adopted to allow the two components to fully react to form a reactive mixture Z; Step S4, pouring the active mixture Z into a pre-treated mold, controlling the temperature and humidity conditions of the foaming process so that it foams and cures in a closed environment to obtain a preliminarily formed polyurethane foam material; Step S5, taking the preliminarily formed polyurethane foam material out of the mold, and then performing heat treatment and surface treatment to finally obtain a corrosion-resistant polyurethane product.

[0007] Optionally, the polyol component containing fluorinated polyether polyol comprises: polyether polyol A, fluorinated modifier B, chain extender C and auxiliary agent D, wherein: The polyether polyol A may be any one of polyoxypropylene diol, polyoxypropylene triol or polyoxyethylene-polyoxypropylene copolyol; The fluorinated modifier B may be any one of a perfluoroalkyl alcohol, a fluorinated alkyl sulfonic acid or a fluorosilane coupling agent; The chain extender C may be any one of 1,4-butanediol, diethylene glycol or trimethylolpropane; The auxiliary agent D may be any one of an antioxidant, an ultraviolet absorber or a hydrophobic additive; The polyether polyol A reacts with the fluorinated modifier B to obtain a fluorinated modified polyether polyol, wherein the fluorinated modified polyether polyol accounts for 70-90 weight % of the polyol component; the chain extender C accounts for 5-20 weight %; and the auxiliary agent D accounts for 0.1-5 weight %.

[0008] Optionally, the organic phosphine preservative is selected from any one of trialkylphosphine, triphenylphosphine or phosphine oxide compounds; the amine catalyst is selected from any one of triethylenediamine, bis(dimethylaminoethyl)ether or N-methylmorpholine; the non-silicon-based surfactant is selected from any one of polyether-modified polyester, sorbitan monostearate or alkyl polyglycoside.

[0009] Optionally, the preparation process of the compound containing two or more active hydrogen groups is: Step S101, providing a polyol E, wherein the polyol E is selected from any one of glycerol, pentaerythritol or sorbitol; Step S102, performing an addition reaction between the polyol E and an epoxy compound F in the presence of a catalyst, wherein the epoxy compound F is selected from any one of ethylene oxide, propylene oxide or epichlorohydrin, the reaction temperature is 50-120° C., the reaction time is 2-6 hours, and a polyether polyol G containing multiple hydroxyl groups is generated; Step S103 , dehydrating and refining the obtained polyether polyol G to remove unreacted substances and by-products, thereby obtaining a high-purity compound containing two or more active hydrogen groups.

[0010] Optionally, the step S3 specifically includes: Step S31, at room temperature, the mixture X and the isocyanate component Y are placed in a constant temperature environment for pretreatment respectively, so that the temperatures of the two are consistent to ensure the stability of the reaction conditions; Step S32, using an electronic balance, accurately weighing the mixture X and the isocyanate component Y in a mass ratio of 1:1; Step S33, pouring the isocyanate component Y into the high-speed reaction kettle, starting the stirrer to pre-stir at a speed of 300-500 rpm for 1-2 minutes to eliminate bubbles in the isocyanate component Y.

[0011] Optionally, after step S33, the following steps are further included: Step S34, while continuously stirring the isocyanate component Y, rapidly adding the mixture X into the reaction kettle within 10-30 seconds; Step S35, increasing the stirring speed to 2000-3000 rpm, and continuing high-speed stirring for 2-5 minutes, so that the mixture X and the isocyanate component Y are fully mixed and reacted to form a reactive mixture Z; during this process, monitoring the temperature of the mixture to maintain the temperature between 25-35° C.; Step S36, during the stirring process, the viscosity change of the active mixture Z is monitored by a particle size detection device. When the viscosity reaches a preset value, the stirring is stopped, and the preparation of the active mixture Z is completed.

[0012] Optionally, the step S4 specifically includes: Step S41, prepare a foaming mold, clean and polish the inner surface of the mold, and then evenly spray a layer of release agent on the inner surface of the mold, wherein the release agent is a semi-permanent release agent, and let it stand for 5-10 minutes to fully dry and form a uniform release layer; Step S42, pouring the prepared active mixture Z into the processed mold, and the pouring process is controlled to be completed within the gel time of the active mixture Z; Step S43, after the active mixture Z is poured into the mold, the mold is immediately closed to form a closed environment in the mold.

[0013] Optionally, after step S43, the following steps are further included: Step S44, placing the closed mold in a constant temperature and humidity foaming chamber, controlling the temperature of the foaming environment to 35-45° C. and the relative humidity to 50-70%, and foaming for 15-30 minutes under this condition. The temperature and humidity during the foaming process are monitored and adjusted in real time by a temperature and humidity controller; Step S45, during the foaming process, applying an external pressure of 0.1-0.3 MPa; Step S46, after the foaming is completed, the temperature and pressure conditions in the mold are maintained and the curing process is continued. The curing time is 30-60 minutes to obtain a preliminarily formed polyurethane foam material.

[0014] Optionally, the step S5 specifically includes: Step S51, taking out the cured polyurethane foam material from the mold, and leaving the taken out polyurethane foam material at room temperature for 1-2 hours to gradually release its internal stress; Step S52, heat-treating the polyurethane foam material, placing the polyurethane foam material in a heat treatment furnace, and adopting a staged heating method, first keeping the temperature at 60-80° C. for 1-2 hours, and then heating to 100-120° C. and keeping the temperature for 2-4 hours; Step S53, after the heat treatment is completed, the polyurethane foam material is taken out from the heat treatment furnace and slowly cooled to room temperature; Step S54, surface treatment of the polyurethane foam material, using plasma treatment and ultraviolet irradiation to modify the surface of the foam material to introduce hydrophilic or hydrophobic groups; wherein the power of the plasma treatment is 50-100 W, and the treatment time is 5-10 minutes; Step S55, after the surface treatment, the polyurethane foam material is subjected to performance testing, the performance testing including density, compression strength, and corrosion resistance index testing, and after confirming that the product meets the preset performance requirements, the preparation of the corrosion-resistant polyurethane product is completed.

[0015] The present invention also provides a corrosion-resistant polyurethane material, which is prepared by the polyurethane foaming process as described above, and the corrosion-resistant polyurethane material specifically comprises: A polyurethane matrix, wherein the polyurethane matrix is ​​formed by reacting a fluorinated modified polyether polyol with a multifunctional isocyanate component, wherein the polyether polyol is prepared by reacting a polyether polyol A with a fluorinated modifier B; Nano graphene oxide filler dispersed in the polyurethane matrix; Organic phosphine anticorrosion additives are used to enhance the corrosion resistance of materials; The cellular structure is obtained by promoting the reaction through an amine catalyst and adopting a non-silicon-based surfactant.

[0016] Compared with the prior art, the invention has the following beneficial effects: during preparation, a polyol component containing a fluorinated modified polyether polyol is mixed with a nano graphene oxide filler, an organic phosphine-based anticorrosive agent, water, an amine catalyst and a non-silicon-based surfactant, thereby improving the hydrophobicity and corrosion resistance of the polyurethane material, providing a multifunctional isocyanate component Y, controlling the reactivity of the isocyanate, and facilitating the configuration with the polyol component; at room temperature, the mixture X and the isocyanate component Y are rapidly mixed in a mass ratio of 1:1, a high-speed stirring method is adopted to ensure that the two components fully react, the active mixture Z is poured into a pre-treated mold, foamed and cured in a closed environment to form a preliminary shape, taken out from the mold, and subjected to subsequent heat treatment and surface treatment, so as to finally obtain a polyurethane product with excellent corrosion resistance; the method realizes the efficient preparation of corrosion-resistant polyurethane materials through the innovative design of material components and process conditions, meets the application requirements under specific corrosion environments, and improves the corrosion resistance and mechanical properties of the materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0019] Figure 1 This is one of the schematic diagrams of the preparation process of the polyurethane foaming process of the first embodiment; Figure 2 This is the second schematic diagram of the preparation process of the polyurethane foaming process of the first embodiment; Figure 3 This is the third schematic diagram of the preparation process of the polyurethane foaming process of the first embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0022] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0023] Embodiment 1: Combination Figures 1 to 3 As shown, an embodiment of the present invention provides a polyurethane foaming process, comprising: Step S1, providing a polyol component containing a fluorinated polyether polyol, mixing the polyol component with a nano-graphene oxide filler, an organic phosphine-based preservative, water, an amine catalyst and a non-silicon-based surfactant, and stirring the mixture to form a uniform mixture X; In the first step, the polyol component required for polyurethane foaming is prepared. By providing a fluorinated polyether polyol, the hydrophobicity and corrosion resistance of the material are improved, which is due to the low surface energy and chemical inertness of the fluorine element. It is mixed with nano-graphene oxide filler, which has excellent mechanical properties and barrier properties and can enhance the strength and durability of the foam. Organic phosphine-based preservatives are added to further improve the stability of the material in a corrosive environment. Water, as a chemical foaming agent, reacts with isocyanate to generate carbon dioxide gas to form a cellular structure. Amine catalysts are used to accelerate the foaming and curing reactions of polyurethane and improve production efficiency. Non-silicon-based surfactants help stabilize the foam cell structure and prevent the cellular merging and collapse. The above ingredients are fully stirred to ensure that the components are evenly dispersed to form a uniform mixture X, laying the foundation for the subsequent foaming reaction.

[0024] Step S2, providing a multifunctional isocyanate component Y, wherein the isocyanate component Y is a prepolymer formed by reacting modified diphenylmethane diisocyanate with a compound containing two or more active hydrogen groups, so that the compound has a reactivity within a preset range; In the second step, isocyanate component Y is prepared, which is an essential reactant in the polyurethane formation process. A multifunctional isocyanate component Y is provided, which is formed by reacting modified diphenylmethane diisocyanate (MDI) with a compound containing two or more active hydrogen groups to form a prepolymer. In the form of a prepolymer, the reactivity of the isocyanate can be adjusted so that it is within a preset range, which facilitates the control of the rate of the foaming reaction and the structure of the foam. The use of the prepolymer can also reduce the volatility of the isocyanate and improve the safety of the production process. This step ensures that the reactivity of the isocyanate component matches the reactivity of the polyol component, preparing for the preparation of a polyurethane foam material with excellent performance.

[0025] Step S3, at room temperature, the mixture X and the isocyanate component Y are rapidly mixed in a mass ratio of 1:1, and high-speed stirring is adopted to allow the two components to fully react to form a reactive mixture Z; In the third step, the mixture X prepared in the first two steps and the isocyanate component Y are mixed and reacted. At room temperature, they are quickly mixed in a mass ratio of 1:1, and the strict ratio ensures the completeness of the reaction and the stability of the product performance. High-speed stirring is adopted, usually at a stirring speed of several thousand revolutions per minute, so that the two components are fully mixed to promote the chemical reaction. High-speed stirring can ensure that the isocyanate is quickly and evenly mixed with components such as polyols and water, and prevents local reactions from being too fast or uneven, resulting in unstable pore structure. During the reaction process, isocyanate and polyol undergo addition reaction to generate a polyurethane main chain, and react with water to generate carbon dioxide gas to form a pore structure. The reactive mixture Z finally formed is a uniform reaction system with ideal foaming properties.

[0026] Step S4, pouring the active mixture Z into a pre-treated mold, controlling the temperature and humidity conditions of the foaming process so that it foams and cures in a closed environment to obtain a preliminarily formed polyurethane foam material; In the fourth step, the active mixture Z is poured into a pre-treated mold for foaming. The mold is cleaned and treated with a release agent before use to ensure that the surface of the product is smooth and easy to demold. It is crucial to control the temperature and humidity conditions of the foaming process, which is usually carried out under a constant temperature and humidity environment to maintain the stability of the reaction and the consistency of the foam structure. Foaming and curing in a closed environment can prevent external humidity and temperature fluctuations from interfering with the foaming process and avoid instability or defects in the pore structure. After a certain period of foaming and curing, the active mixture Z gradually forms a polyurethane foam material with a continuous pore structure, and the initially formed product has the expected size and shape.

[0027] Step S5, taking the preliminarily formed polyurethane foam material out of the mold, and then performing heat treatment and surface treatment to finally obtain a corrosion-resistant polyurethane product.

[0028] In the fifth step, the initially formed polyurethane foam material is removed from the mold. Subsequently, heat treatment is carried out, usually heating at a specific temperature for a certain period of time to further complete the reaction inside the material, eliminate internal stress, and improve the mechanical properties and dimensional stability of the material. Surface treatment is then carried out, and methods such as plasma treatment, ultraviolet irradiation, or coating of a protective layer can be used to enhance the corrosion resistance and other properties of the material surface. After these treatments, the corrosion-resistant polyurethane products finally obtained have excellent physical and chemical properties, and can be used stably for a long time in corrosive environments such as high humidity and high salinity, meeting the application requirements in specific scenarios.

[0029] The working principle of the invention is as follows: during preparation, a polyol component containing a fluorinated modified polyether polyol is mixed with a nano graphene oxide filler, an organic phosphine-based anticorrosive agent, water, an amine catalyst and a non-silicon-based surfactant, thereby improving the hydrophobicity and corrosion resistance of the polyurethane material, providing a multifunctional isocyanate component Y, controlling the reactivity of the isocyanate, and facilitating the configuration with the polyol component; at room temperature, the mixture X and the isocyanate component Y are rapidly mixed in a mass ratio of 1:1, a high-speed stirring method is adopted to ensure that the two components fully react, the active mixture Z is poured into a pre-treated mold, foamed and cured in a closed environment to form a preliminary shape, taken out from the mold, and subsequently subjected to heat treatment and surface treatment, so as to finally obtain a polyurethane product with excellent corrosion resistance; the method realizes the efficient preparation of corrosion-resistant polyurethane materials through innovative design of material components and process conditions, meets the application requirements under specific corrosion environments, and improves the corrosion resistance and mechanical properties of the materials.

[0030] In this embodiment, the polyol component containing fluorinated polyether polyol comprises: polyether polyol A, fluorinated modifier B, chain extender C and auxiliary agent D, wherein: The polyether polyol A can be any one of polyoxypropylene diol, polyoxypropylene triol or polyoxyethylene-polyoxypropylene copolyol. These polyether polyols have different molecular weights and functionalities, provide active hydrogen groups required for polyurethane reaction, and affect the flexibility and mechanical properties of the final foam.

[0031] The fluorinated modifier B can be any one of perfluoroalkyl alcohol, fluorinated alkyl sulfonic acid or fluorosilane coupling agent. The fluorinated modifier reacts with the polyether polyol A to introduce fluorine element to form a fluorinated modified polyether polyol. This structural adjustment gives the polyurethane material excellent hydrophobicity and corrosion resistance because the fluorine element has extremely low surface energy and high chemical inertness.

[0032] The chain extender C can be any one of 1,4-butanediol, diethylene glycol or trimethylolpropane. The chain extender plays a role in adjusting the molecular chain length and hardness in the synthesis of polyurethane, and affects the mechanical properties and thermal properties of the material.

[0033] The additive D may be any one of an antioxidant, an ultraviolet absorber or a hydrophobic additive; the addition of the additive can improve the aging resistance of the material, resist the influence of environmental factors such as oxidation and ultraviolet rays, and extend the service life of the material.

[0034] Polyether polyol A reacts with fluorinated modifier B to obtain fluorinated modified polyether polyol, wherein the fluorinated modified polyether polyol accounts for 70-90 weight percent of the polyol component; the chain extender C accounts for 5-20 weight percent; and the auxiliary agent D accounts for 0.1-5 weight percent.

[0035] During the preparation process, polyether polyol A reacts with fluorinated modifier B to obtain fluorinated modified polyether polyol. The fluorinated modified polyether polyol accounts for 70-90% by weight in the polyol component, ensuring that the material has sufficient fluorine content to provide excellent corrosion resistance. Chain extender C accounts for 5-20% by weight and is used to adjust the hardness and strength of the polyurethane. Auxiliary agent D accounts for 0.1-5% by weight. Although the addition amount is small, it has a significant effect on the stability and durability of the material.

[0036] In this embodiment, the organic phosphine preservative is selected from any one of trialkylphosphine, triphenylphosphine or phosphine oxide compounds; the amine catalyst is selected from any one of triethylenediamine, bis(dimethylaminoethyl)ether or N-methylmorpholine; the non-silicon-based surfactant is selected from any one of polyether-modified polyester, sorbitan monostearate or alkyl polyglycoside.

[0037] By selecting and matching the above components, the prepared polyurethane foam material not only meets the requirements of the foaming process, but also further enhances the corrosion resistance, mechanical properties and stability of the material. It is suitable for applications in special corrosive environments such as high humidity and high salinity (such as chemical plants, sewage treatment plants, mine tunnels, etc.).

[0038] In this embodiment, it is specifically described that the preparation process of the compound containing two or more active hydrogen groups is: Step S101, providing a polyol E, wherein the polyol E is selected from any one of glycerol, pentaerythritol or sorbitol; First, select an appropriate polyol E as the starting material for synthesizing compounds containing two or more active hydrogen groups. Polyol E can be selected from any one of glycerol, pentaerythritol or sorbitol. These polyols all have multiple hydroxyl (-OH) functional groups, which can provide active hydrogen atoms and undergo ring-opening addition reactions with epoxy compounds. Among them, glycerol is a triol with three hydroxyl groups; pentaerythritol is a tetraol with four hydroxyl groups; and sorbitol is a hexaol with six hydroxyl groups. According to the functionality and performance requirements of the required polyether polyol, select an appropriate polyol E to provide multiple active reaction sites for subsequent reactions.

[0039] Step S102, performing an addition reaction between polyol E and epoxy compound F in the presence of a catalyst, wherein the epoxy compound F is selected from any one of ethylene oxide, propylene oxide or epichlorohydrin, the reaction temperature is 50-120° C., the reaction time is 2-6 hours, and a polyether polyol G containing multiple hydroxyl groups is generated; It should be noted that the selected polyol E is subjected to an addition reaction with the epoxy compound F in the presence of a catalyst. The epoxy compound F can be selected from any one of ethylene oxide, propylene oxide or epichlorohydrin. These epoxy compounds have a cyclic oxygen bridge structure and are prone to ring-opening reaction under the action of an acid or alkaline catalyst. The reaction temperature is controlled at 50-120°C and the reaction time is 2-6 hours. By adjusting the reaction temperature and time, the molecular weight and structure of the polyether polyol can be controlled. The catalyst can be an alkali metal hydroxide, a double metal cyanide complex, and the like. The hydroxyl group of the polyol E undergoes a ring-opening polymerization reaction with the epoxy group of the epoxy compound F, gradually growing the molecular chain to generate a polyether polyol G containing multiple hydroxyl groups. The polyether polyol G has the required molecular weight and functionality, and provides a key raw material for the preparation of polyurethane materials.

[0040] Step S103 , dehydrating and refining the obtained polyether polyol G to remove unreacted substances and by-products, thereby obtaining a high-purity compound containing two or more active hydrogen groups.

[0041] The polyether polyol G obtained by the reaction is subjected to dehydration and refining treatment. Since there may be unreacted raw materials, excess catalysts and by-products in the reaction process, these impurities will affect the purity of the polyether polyol and the performance of subsequent reactions. Dehydration treatment usually uses reduced pressure distillation or heating to remove residual water. Refining treatment removes unreacted substances and by-products, such as low molecular weight polymers or catalyst residues, by filtering, distillation or other purification methods. After dehydration and refining treatment, a high-purity compound containing two or more active hydrogen groups is obtained, that is, high-quality polyether polyol G. This compound has stable chemical properties and good reactivity, and can be used to react with isocyanate to prepare polyurethane prepolymers with excellent performance.

[0042] In this embodiment, it is specifically described that step S3 specifically includes: Step S31, at room temperature, the mixture X and the isocyanate component Y are placed in a constant temperature environment for pretreatment respectively, so that the temperatures of the two are consistent to ensure the stability of the reaction conditions; The mixture A and the isocyanate component B are pretreated in a constant temperature environment at room temperature (generally 20-25°C) to make the temperatures of the two consistent, in order to ensure the stability and controllability of the subsequent reaction conditions.

[0043] Step S32, using an electronic balance, accurately weigh the mixture X and the isocyanate component Y in a mass ratio of 1:1; the weighing error is controlled within ±0.1% to ensure the accuracy of the ratio; the mass ratio of 1:1 means that the equivalent ratio of the two components matches, which helps to achieve a complete reaction, avoid excessive isocyanate or polyol residues, and prevent the degradation of foam performance or defects caused by improper ratio.

[0044] Step S33, pouring the isocyanate component Y into the high-speed reaction kettle, starting the stirrer to pre-stir at a speed of 300-500 rpm for 1-2 minutes to eliminate bubbles in the isocyanate component Y and ensure its uniformity; Pour the isocyanate component B into the high-speed reactor and start the agitator to pre-stir for 1-2 minutes at 300-500 rpm. The purpose of this pre-stirring step is to eliminate bubbles in component B and ensure its uniformity. The presence of bubbles may introduce defects during the reaction, resulting in uneven foam structure or voids. Moderate pre-stirring can release small bubbles suspended in the liquid, improve the purity and reactivity of the isocyanate component, and lay a good foundation for subsequent steps.

[0045] Step S34, while continuously stirring the isocyanate component Y, quickly add the mixture X into the reactor within 10-30 seconds to avoid excessive local reaction due to slow addition; While continuously stirring the isocyanate component B, quickly add the mixture A to the reactor within 10-30 seconds. The purpose of quickly adding the mixture A is to prevent excessive isocyanate in a local area, which may lead to excessive or uneven reaction. Continuous stirring helps to quickly disperse the mixture A, so that it can fully contact with the isocyanate component B and promote uniform reaction. Controlling the addition time can avoid a sudden rise in the temperature of the reaction system and ensure the controllability and stability of the reaction.

[0046] Step S35, increasing the stirring speed to 2000-3000 rpm, and continuing high-speed stirring for 2-5 minutes, so that the mixture X and the isocyanate component Y are fully mixed and reacted to form a reactive mixture Z; during this process, monitoring the temperature of the mixture to maintain the temperature between 25-35° C. to prevent overheating of the reaction from affecting the quality of the product; Increase the stirring speed to 2000-3000 rpm, and continue stirring at high speed for 2-5 minutes to fully mix and react mixture A with isocyanate component B to form active mixture C. During this process, the temperature of the mixture needs to be monitored in real time to ensure that the temperature remains between 25-35°C. High-speed stirring can improve mixing efficiency, promote full reaction at the microscopic level, and obtain a uniform active mixture. Temperature control is crucial because the polyurethane reaction is an exothermic reaction, and excessively high temperatures may trigger side reactions or cause a decrease in foam quality. By monitoring and controlling the temperature, ensure that the reaction is carried out within the optimal temperature range to obtain an active mixture C with stable performance.

[0047] Step S36, during the stirring process, the viscosity change of the active mixture Z is monitored by a particle size detection device. When the viscosity reaches a preset value, the stirring is stopped, and the preparation of the active mixture Z is completed.

[0048] The change in viscosity reflects the progress of the reaction and the degree of mixing. When the viscosity reaches the preset value, it indicates that the reaction has reached an ideal state and the active mixture has suitable fluidity and reactivity. Stopping stirring in time can avoid over-stirring or over-reaction, and prevent processing difficulties or damage to foam quality due to high viscosity. At this point, the active mixture C is ready for further foaming.

[0049] In this embodiment, it is specifically described that step S4 specifically includes: Step S41, prepare the foaming mold, clean and polish the inner surface of the mold to ensure that there is no dust, oil stains and impurities left, and then evenly spray a layer of release agent on the inner surface of the mold. The release agent should be a highly efficient and environmentally friendly semi-permanent release agent. Let it stand for 5-10 minutes to allow it to fully dry and form a uniform release layer.

[0050] It should be noted that the purpose of cleaning and polishing the inner surface of the mold is to remove any dust, grease or other impurities that may affect the surface quality of the foam, ensuring that the surface of the product is smooth and defect-free. Then, spray a layer of release agent evenly on the inner surface of the mold. Choose a semi-permanent release agent, which is efficient and durable and can be used multiple times to reduce production costs and maintenance time. Let it stand for 5-10 minutes to allow the release agent to fully dry and form a uniform release layer to ensure that the subsequent demoulding process goes smoothly and prevent the polyurethane foam from sticking to the mold.

[0051] Step S42, pouring the prepared active mixture Z into the processed mold, and the pouring process is controlled to be completed within the gel time of the active mixture Z; to prevent the material from solidifying prematurely and affecting the foaming effect.

[0052] The pouring process must be completed within the gel time of the active mixture C. The gel time refers to the time it takes for the mixture to change from liquid to gel, which is usually only a few minutes. Therefore, the pouring process needs to be completed quickly and accurately to ensure that the mixture fills all parts of the mold in a state of good fluidity to avoid voids or defects. The pouring process must be smooth to prevent bubbles from mixing in or splashing, which will affect the quality of the product.

[0053] Step S43, after the active mixture Z is poured into the mold, the mold is immediately closed to form a closed environment in the mold to prevent external air and humidity from interfering with the foaming process.

[0054] Step S44, placing the closed mold in a constant temperature and humidity foaming chamber, controlling the temperature of the foaming environment to 35-45°C and the relative humidity to 50-70%, and foaming for 15-30 minutes under this condition. The temperature and humidity during the foaming process are monitored and adjusted in real time by a temperature and humidity controller to ensure the stable progress of the foaming reaction.

[0055] In step S44, the closed mold is placed in a constant temperature and humidity foaming chamber to provide stable environmental conditions for foaming and curing. The temperature of the foaming environment is controlled to be 35-45°C and the relative humidity is 50-70%. These conditions are conducive to the smooth progress of the polyurethane reaction and the formation of the pore structure. Foaming is carried out under this condition for 15-30 minutes to fully expand the material and partially cure it. The temperature and humidity during the foaming process are monitored and adjusted in real time by a temperature and humidity controller to ensure the accuracy and stability of environmental parameters and avoid the impact of environmental fluctuations on foam quality.

[0056] Step S45, during the foaming process, applying an external pressure of 0.1-0.3 MPa to improve the density and uniformity of the foam, reduce cell defects, and obtain better mechanical properties.

[0057] Step S46, after the foaming is completed, the temperature and pressure conditions in the mold are maintained, and the curing process is continued for 30-60 minutes to obtain a preliminarily formed polyurethane foam material. Ensure that the reaction inside the foam material is fully completed and the expected performance indicators are achieved; after the curing is completed, slowly release the pressure in the mold, open the mold, and carefully take out the preliminarily formed polyurethane foam material to avoid damage to the surface of the material.

[0058] In this embodiment, it is specifically described that step S5 specifically includes: Step S51, taking out the cured polyurethane foam material from the mold, and placing the taken out polyurethane foam material at room temperature for 1-2 hours to gradually release its internal stress, so as to avoid cracking or deformation of the material due to sudden temperature change; Step S52, heat-treating the polyurethane foam material, placing the polyurethane foam material in a heat treatment furnace, and adopting a staged heating method, first keeping the temperature at 60-80°C for 1-2 hours, and then heating to 100-120°C and keeping the temperature for 2-4 hours; so as to further promote the cross-linking reaction inside the material and improve the mechanical properties and stability of the material; Step S53, after the heat treatment is completed, the polyurethane foam material is taken out from the heat treatment furnace and slowly cooled to room temperature to avoid the increase of internal stress of the material caused by rapid cooling; Step S54, surface treatment of the polyurethane foam material, using plasma treatment and ultraviolet irradiation to modify the surface of the foam material to introduce hydrophilic or hydrophobic groups to improve the corrosion resistance of the material surface; wherein the power of the plasma treatment is 50-100 W, and the treatment time is 5-10 minutes; Step S55, after the surface treatment, the polyurethane foam material is subjected to performance testing, the performance testing including density, compression strength, and corrosion resistance index testing, and after confirming that the product meets the preset performance requirements, the preparation of the corrosion-resistant polyurethane product is completed.

[0059] Embodiment 2: The present invention further provides a corrosion-resistant polyurethane material, which is prepared by the polyurethane foaming process of Example 1. The corrosion-resistant polyurethane material specifically comprises: A polyurethane matrix, wherein the polyurethane matrix is ​​formed by reacting a fluorinated modified polyether polyol with a multifunctional isocyanate component, wherein the polyether polyol is prepared by reacting a polyether polyol A with a fluorinated modifier B; Nano-graphene oxide fillers dispersed in a polyurethane matrix; Organic phosphine anticorrosion additives are used to enhance the corrosion resistance of materials; The cellular structure is obtained by promoting the reaction through an amine catalyst and using a non-silicon-based surfactant.

[0060] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polyurethane foaming process, characterized in that: include: Step S1, providing a polyol component containing a fluorinated polyether polyol, mixing the polyol component with a nano-graphene oxide filler, an organic phosphine-based preservative, water, an amine catalyst and a non-silicon-based surfactant, and stirring the mixture to form a uniform mixture X; Step S2, providing a multifunctional isocyanate component Y, wherein the isocyanate component Y is a prepolymer formed by reacting modified diphenylmethane diisocyanate with a compound containing two or more active hydrogen groups, so that the compound has a reactivity within a preset range; Step S3, at room temperature, the mixture X and the isocyanate component Y are rapidly mixed in a mass ratio of 1:1, and high-speed stirring is adopted to allow the two components to fully react to form a reactive mixture Z; Step S4, pouring the active mixture Z into a pre-treated mold, controlling the temperature and humidity conditions of the foaming process so that it foams and cures in a closed environment to obtain a preliminarily formed polyurethane foam material; Step S5, taking the preliminarily formed polyurethane foam material out of the mold, and then performing heat treatment and surface treatment to finally obtain a corrosion-resistant polyurethane product.

2. The polyurethane foaming process according to claim 1, characterized in that: The polyol component containing fluorinated polyether polyol comprises: polyether polyol A, fluorinated modifier B, chain extender C and auxiliary agent D, wherein: The polyether polyol A may be any one of polyoxypropylene diol, polyoxypropylene triol or polyoxyethylene-polyoxypropylene copolyol; The fluorinated modifier B may be any one of a perfluoroalkyl alcohol, a fluorinated alkyl sulfonic acid or a fluorosilane coupling agent; The chain extender C may be any one of 1,4-butanediol, diethylene glycol or trimethylolpropane; The auxiliary agent D may be any one of an antioxidant, an ultraviolet absorber or a hydrophobic additive; The polyether polyol A reacts with the fluorinated modifier B to obtain a fluorinated modified polyether polyol, wherein the fluorinated modified polyether polyol accounts for 70-90 weight % of the polyol component; the chain extender C accounts for 5-20 weight %; and the auxiliary agent D accounts for 0.1-5 weight %.

3. The polyurethane foaming process according to claim 1, characterized in that: The organic phosphine preservative is selected from any one of trialkylphosphine, triphenylphosphine or phosphine oxide compounds; the amine catalyst is selected from any one of triethylenediamine, bisdimethylaminoethyl ether or N-methylmorpholine; the non-silicon-based surfactant is selected from any one of polyether-modified polyester, sorbitan monostearate or alkyl polyglycoside.

4. The polyurethane foaming process according to claim 1, characterized in that: The preparation process of the compound containing two or more active hydrogen groups is as follows: Step S101, providing a polyol E, wherein the polyol E is selected from any one of glycerol, pentaerythritol or sorbitol; Step S102, performing an addition reaction between the polyol E and an epoxy compound F in the presence of a catalyst, wherein the epoxy compound F is selected from any one of ethylene oxide, propylene oxide or epichlorohydrin, the reaction temperature is 50-120° C., the reaction time is 2-6 hours, and a polyether polyol G containing multiple hydroxyl groups is generated; Step S103 , dehydrating and refining the obtained polyether polyol G to remove unreacted substances and by-products, thereby obtaining a high-purity compound containing two or more active hydrogen groups.

5. The polyurethane foaming process according to claim 1, characterized in that: The step S3 specifically includes: Step S31, at room temperature, the mixture X and the isocyanate component Y are placed in a constant temperature environment for pretreatment respectively, so that the temperatures of the two are consistent to ensure the stability of the reaction conditions; Step S32, using an electronic balance, accurately weighing the mixture X and the isocyanate component Y in a mass ratio of 1:1; Step S33, pouring the isocyanate component Y into the high-speed reaction kettle, starting the stirrer to pre-stir at a speed of 300-500 rpm for 1-2 minutes to eliminate bubbles in the isocyanate component Y.

6. The polyurethane foaming process according to claim 5, characterized in that: After step S33, the following steps are also included: Step S34, while continuously stirring the isocyanate component Y, rapidly adding the mixture X into the reaction kettle within 10-30 seconds; Step S35, increasing the stirring speed to 2000-3000 rpm, and continuing high-speed stirring for 2-5 minutes, so that the mixture X and the isocyanate component Y are fully mixed and reacted to form a reactive mixture Z; during this process, monitoring the temperature of the mixture to maintain the temperature between 25-35° C.; Step S36, during the stirring process, the viscosity change of the active mixture Z is monitored by a particle size detection device. When the viscosity reaches a preset value, the stirring is stopped, and the preparation of the active mixture Z is completed.

7. The polyurethane foaming process according to claim 1, characterized in that: The step S4 specifically includes: Step S41, prepare a foaming mold, clean and polish the inner surface of the mold, and then evenly spray a layer of release agent on the inner surface of the mold, wherein the release agent is a semi-permanent release agent, and let it stand for 5-10 minutes to fully dry and form a uniform release layer; Step S42, pouring the prepared active mixture Z into the processed mold, and the pouring process is controlled to be completed within the gel time of the active mixture Z; Step S43, after the active mixture Z is poured into the mold, the mold is immediately closed to form a closed environment in the mold.

8. The polyurethane foaming process according to claim 7, characterized in that: After step S43, the following steps are further included: Step S44, placing the closed mold in a constant temperature and humidity foaming chamber, controlling the temperature of the foaming environment to 35-45° C. and the relative humidity to 50-70%, and foaming for 15-30 minutes under this condition. The temperature and humidity during the foaming process are monitored and adjusted in real time by a temperature and humidity controller; Step S45, during the foaming process, applying an external pressure of 0.1-0.3 MPa; Step S46, after the foaming is completed, the temperature and pressure conditions in the mold are maintained and the curing process is continued. The curing time is 30-60 minutes to obtain a preliminarily formed polyurethane foam material.

9. The polyurethane foaming process according to claim 1, characterized in that: The step S5 specifically includes: Step S51, taking out the cured polyurethane foam material from the mold, and leaving the taken out polyurethane foam material at room temperature for 1-2 hours to gradually release its internal stress; Step S52, heat-treating the polyurethane foam material, placing the polyurethane foam material in a heat treatment furnace, and adopting a staged heating method, first keeping the temperature at 60-80° C. for 1-2 hours, and then heating to 100-120° C. and keeping the temperature for 2-4 hours; Step S53, after the heat treatment is completed, the polyurethane foam material is taken out from the heat treatment furnace and slowly cooled to room temperature; Step S54, surface treatment of the polyurethane foam material, using plasma treatment and ultraviolet irradiation to modify the surface of the foam material to introduce hydrophilic or hydrophobic groups; wherein the power of the plasma treatment is 50-100 W, and the treatment time is 5-10 minutes; Step S55, after the surface treatment, the polyurethane foam material is subjected to performance testing, the performance testing including density, compression strength, and corrosion resistance index testing, and after confirming that the product meets the preset performance requirements, the preparation of the corrosion-resistant polyurethane product is completed.

10. A corrosion-resistant polyurethane material, characterized in that: The corrosion-resistant polyurethane material is prepared by the polyurethane foaming process according to any one of claims 1 to 9, and specifically comprises: A polyurethane matrix, wherein the polyurethane matrix is ​​formed by reacting a fluorinated modified polyether polyol with a multifunctional isocyanate component, wherein the polyether polyol is prepared by reacting a polyether polyol A with a fluorinated modifier B; Nano graphene oxide filler dispersed in the polyurethane matrix; Organic phosphine anticorrosion additives are used to enhance the corrosion resistance of materials; The cellular structure is obtained by promoting the reaction through an amine catalyst and adopting a non-silicon-based surfactant.

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