Polyurethane resin matrix material for composites and use thereof, liquid moulded composite
By using specific isocyanate components and redox systems in polyurethane resins, the problems of reactivity and moisture sensitivity of polyurethane resins were solved, improving the heat resistance and mechanical properties of the materials while extending the operating time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2022-07-01
- Publication Date
- 2026-05-19
AI Technical Summary
Polyurethane resin, as the matrix of composite materials, has high reactivity, resulting in short working time. In addition, isocyanates are highly sensitive to water vapor and easily react with water in high humidity environments to generate bubbles, which affects the material performance.
Diphenylmethane diisocyanate and dimethylene triphenyl triisocyanate were used as isocyanate components, and initiators, catalysts and polymerization inhibitors in the redox system were combined to adjust the reaction rate, reduce moisture sensitivity and extend the operating time.
It significantly improves the heat resistance and mechanical properties of polyurethane resin, reduces the sensitivity of isocyanate to moisture, avoids bubble formation, and extends the working time.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polyurethane and composite materials, specifically relating to a polyurethane resin matrix material for composite materials, its use in manufacturing liquid molding composite materials, and also relating to a liquid molding composite material. Background Technology
[0002] Composite materials were first used in high-end fields such as aerospace and military defense. However, with the development of the national economy, the application of composite materials in civilian fields such as energy, transportation, construction, sports and leisure is changing rapidly. Especially in the field of new energy such as wind power, photovoltaics, and hydrogen energy, composite materials are playing a key supporting role. Compared with other thermosetting resins such as epoxy resin, polyurethane resin itself has higher reactivity and toughness. At the same time, its molecular and formulation properties have the characteristics of being designable and adjustable within a wide range, with good design freedom. As a resin matrix for composite materials, it has broad application potential.
[0003] Invention patent CN105778005B discloses a polyurethane composition that can be polymerized by free radicals, comprising isocyanate containing active olefin bonds and its prepolymer, and a reactive diluent. This composition is suitable for various composite material molding methods such as pultrusion, winding, infusion, and hand lay-up molding.
[0004] Invention patent CN104974502B discloses a polyurethane composite material and its preparation method. By introducing a hydroxyl-containing acrylate reactive component into a polyurethane system of polyether polyol and isocyanate, the system simultaneously exhibits the reaction of isocyanate and hydroxyl groups and free radical reaction, thus preparing a polyurethane composite material with excellent mechanical properties.
[0005] However, polyurethane resins, as the matrix of composite materials, still present unresolved problems. On the one hand, due to their high reactivity, viscosity increases rapidly, making it difficult to guarantee a sufficiently long working time. On the other hand, isocyanates are more sensitive to moisture; in high humidity environments, the resin matrix easily reacts with water to generate bubbles, thus affecting the performance of the composite material. Summary of the Invention
[0006] To address the aforementioned problems in the prior art, this invention provides a polyurethane resin matrix material for composite materials. This material not only significantly improves the heat resistance and mechanical properties of the matrix resin, but also reduces the sensitivity of isocyanate to environmental moisture, preventing the formation of numerous bubbles upon contact with moisture, and extends the workability of the polyurethane resin matrix material.
[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0008] A polyurethane resin matrix material for composite materials, said polyurethane resin matrix material being prepared by a polyurethane composition comprising:
[0009] A) Isocyanate component, wherein the isocyanate component comprises diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate, wherein the isocyanate component contains 4-28 wt% of 2,4'-diphenylmethane diisocyanate and 12-27% of dimethylene triphenyl triisocyanate.
[0010] B) Organic polyol components;
[0011] C) (Meth)acrylate components that have reactive active hydrogen atoms that resonate with isocyanate groups;
[0012] D) Redox system.
[0013] This invention, through the design of the content of two isocyanate components with different structures, 2,4-diphenylmethane diisocyanate and dimethylene triphenyl triisocyanate, not only significantly improves the heat resistance and mechanical properties of the matrix resin, but also reduces the sensitivity of isocyanates to environmental moisture, avoids the generation of a large number of bubbles when the resin system comes into contact with moisture, and extends the workability of the polyurethane resin matrix material.
[0014] The polyurethane resin matrix material of the present invention has a content of 36-55 wt% for component A), calculated based on a total mass of 100 wt% of the polyurethane matrix material.
[0015] The polyurethane resin matrix material of the present invention, wherein component B) is selected from one or more of polyether polyols, polyester polyols or small molecule polyols; preferably, the organic polyol component contains a polyether polyol with a molecular weight of 120-500, a functionality of 2-4, and a hydroxyl value of 100-600 mgKOH / g.
[0016] Preferably, the content of component B is 24-35 wt%, calculated based on the total mass of the polyurethane matrix material as 100 wt%.
[0017] In the polyurethane resin matrix material of the present invention, component C) is selected from one or more combinations of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.
[0018] The polyurethane resin matrix material of the present invention has a content of 15-39 wt% for the (meth)acrylate component having reactive active hydrogen with the isocyanate group, calculated based on a total mass of 100 wt% of the polyurethane matrix material.
[0019] The polyurethane resin matrix material of this invention comprises an initiator (D1), a catalyst (D2), and a polymerization inhibitor (D3). Through the synergistic effect of the initiator, catalyst, and polymerization inhibitor, the free radical reaction time is delayed, the rate of free radical polymerization is adjusted, thereby further extending the operating time and solving the problem of concentrated exothermic reaction during the polyurethane resin curing process.
[0020] Preferably, the D1 component is selected from one or more peroxide initiators, such as benzoyl peroxide, tert-butyl peroxide-2-ethylhexyl carbonate, methyl ethyl ketone peroxide, or one or more of these, and is added in an amount of 0.1-1.1 wt% of the total mass of the polyurethane matrix material.
[0021] The catalyst component D2 is selected from one or more organometallic compounds of copper, potassium, calcium, cobalt, and sodium, preferably isooctanoate or naphthenate of cobalt metal, and is added in an amount of 10-100 ppm of the total mass of the polyurethane matrix material.
[0022] The polyurethane resin matrix material of this invention, wherein the D3 component is selected from one or more combinations of quinone and phenolic polymerization inhibitors; including but not limited to one or more of tetrachlorobenzoquinone, 1,4-naphthoquinone, methylhydroquinone (THQ), p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone. The addition amount is 40-600 ppm of the total mass of the polyurethane matrix material.
[0023] As a preferred embodiment, the method for preparing the polyurethane resin matrix material of the present invention includes the following steps:
[0024] 1) Preparation of black material: The isocyanate component and initiator are uniformly mixed in a closed environment at room temperature;
[0025] 2) Preparation of white material: The organic polyol component, the (meth)acrylate component with reactive active hydrogen to the isocyanate group, the polymerization inhibitor, and the catalyst are uniformly mixed in a closed environment at room temperature;
[0026] 3) Mix the black and white materials evenly, and mix them mechanically at room temperature for 10-20 minutes at a speed of 500-1000 r / min to obtain the polyurethane resin matrix material. Then, vacuum degas at room temperature for 3-5 minutes.
[0027] The polyurethane resin matrix material described in this invention can be used to manufacture liquid-molded composite materials, such as wind turbine blade composite materials.
[0028] A liquid molding composite material includes a polyurethane matrix material and a reinforcing material, with a mass ratio of 1:(1.5-5).
[0029] Preferably, the reinforcing material is selected from one or more combinations of glass fiber, carbon fiber, carbon nanotube, graphene, aramid fiber, natural fiber, ultra-high molecular weight polyethylene fiber, boron fiber, silicon carbide fiber, polyester fiber, nylon fiber, basalt fiber, and whiskers.
[0030] More preferably, the liquid molding composite material is prepared by resin transfer molding (RTM), wet compression molding (WCM), filament winding, pultrusion, or vacuum injection molding, with vacuum injection or RTM molding being preferred.
[0031] The vacuum infusion molding process involves first laying the reinforcing material (fiber fabric, core material) in a mold, creating a negative pressure environment through a vacuum bag, then introducing the polyurethane matrix material into the mold to fully impregnate the fiberglass fabric, then heating to the curing temperature, maintaining it for a certain time to complete the curing and molding, and finally demolding to complete the preparation of the polyurethane composite material.
[0032] More preferably, during the liquid molding process, the curing temperature is 40-100℃, and the curing time is 2-7 hours. Compared with the prior art, the positive effects of this invention are:
[0033] (1) By adjusting the content of 2,4-diphenylmethane diisocyanate in the isocyanate component, the present invention significantly reduces the sensitivity of isocyanate to water vapor, effectively solving the problem of bubbles generated in the polyurethane matrix during processing and curing. At the same time, the lower reactivity of the isocyanate also helps to extend the working time of the polyurethane resin matrix material. Furthermore, the introduction of 2,4-diphenylmethane diisocyanate and trifunctional isocyanate (dimethylene triphenyl triisocyanate) enhances the rigidity of the polyurethane molecular chain and increases the crosslinking density in the microstructure. Therefore, the heat distortion temperature and modulus of the polyurethane matrix resin are greatly improved, achieving unexpected results.
[0034] (2) In the preferred redox system, through the combination of initiator, catalyst and polymerization inhibitor, the polymerization inhibitor delays the free radical reaction time, and the initiator and catalyst regulate the rate of free radical polymerization reaction, thereby further extending the operation time and reducing the peak exothermic temperature of polyurethane resin curing.
[0035] Attached image description: Figure 1 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared in Example 1.
[0036] Figure 2 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared in Example 2.
[0037] Figure 3 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared in Example 3.
[0038] Figure 4 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared for Comparative Example 1.
[0039] Figure 5 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared for Comparative Example 2.
[0040] Figure 6 Photographs of the water vapor sensitivity test of the polyurethane resin matrix prepared for Comparative Example 3. Detailed Implementation
[0041] The present invention will be further illustrated by specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.
[0042] I. The main raw materials and their sources in the embodiments are detailed in Table 1.
[0043] Table 1 Raw Materials and Sources
[0044]
[0045]
[0046] Unless otherwise specified in Table 1, all other raw materials were purchased from the market.
[0047] II. Performance Testing Methods:
[0048] Viscosity testing method: The viscosity was tested using a Bollerfeld DV-II rotational viscometer.
[0049] Gel time test method: hot plate method, resin thickness 1mm, stirring and stringing method to determine gel point;
[0050] Mechanical property testing methods: The polyurethane matrix resin material was cured at 80℃ for 4 hours to prepare mechanical property test strips, which were then tested using a universal testing machine from Instron Corporation, USA. The mechanical properties of the resin matrix material were tested according to standard GB / T 2567. The fracture toughness KIC test was performed according to ASTM D 5045-99. The tensile properties of the polyurethane composite material were tested according to standard ISO 527-5. The interlaminar shear strength of the polyurethane composite material was tested according to standard ASTM 7078.
[0051] Heat distortion temperature (HDT): Heating rate: 2℃ / min, Test standard: ISO-306.
[0052] Peak exothermic temperature: 100g resin, 25℃ circulating water bath, temperature change recorded by paperless recorder;
[0053] Air humidity sensitivity test: After mixing and degassing 25 grams of polyurethane composition, place it in a wide-mouth container and then place it in a constant temperature and humidity chamber. Control the temperature at 25℃ and the humidity at 40% for 0.5 hours and observe the number of bubbles generated.
[0054] Examples 1-3: Preparation of polyurethane resin matrix
[0055] Methods for preparing resin matrix materials:
[0056] 1) First, vacuum dry the glass plate casting mold system in a 100℃ oven for 4 hours, and then cool it to 70℃;
[0057] 2) Preparation of black material: Isocyanate and initiator are mixed uniformly in a certain proportion in a closed environment at room temperature;
[0058] 3) Preparation of white material: Organic polyol, (meth)acrylate component with reactive active hydrogen to isocyanate group, polymerization inhibitor, catalyst are mixed uniformly in a closed environment in a certain proportion, and the mixing temperature is room temperature;
[0059] 4) Mix the black and white components evenly, and mix mechanically at room temperature for 10-20 minutes at a speed of 500-1000 r / min to obtain the polyurethane matrix resin material. Then, degas under vacuum at room temperature for 3-5 minutes. Take 25 grams of the polyurethane matrix resin for water resistance testing.
[0060] 5) Slowly pour the polyurethane matrix resin material into the mold and cure it at 70°C for 4 hours to obtain the polyurethane resin matrix material of Examples 1-5.
[0061] Table 1 shows the mass of each component added in the examples.
[0062]
[0063]
[0064] Table 2. Performance test results of polyurethane compositions in the examples and comparative examples
[0065] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Mixed viscosity (cps) at 25℃ 49 54 73 40 320 76 Operation time (min / 25℃) 127 121 98 81 61 48 Gel time (min / 40℃) 170 162 149 97 82 62 Maximum heat release temperature (25℃) 47 53 76 32 172 151 Water vapor sensitivity (bubble volume) + + ++ ++ +++++ ++++ Tensile strength (MPa) 83 88 75 53 58 62 Tensile modulus (GPa) 3.6 3.5 3.1 2.7 3.0 3.1 Bending strength (MPa) 130 138 112 89 92 112 Flexural modulus (MPa) 3.5 3.4 3.0 2.5 2.9 3.0 Elongation at break (%) 6.1 6.5 5.5 4.9 3.2 2.7 Heat distortion temperature (HDT) (°C) 69 68 63 48 51 60
[0066] A comparison of the performance data of the embodiments and the comparative examples in Table 2 shows that, firstly, the embodiments, compared to the comparative examples, exhibit reduced sensitivity to environmental moisture and are less likely to react with moisture to produce bubbles under the same humidity conditions. (See Appendix) Figure 1-6Second, compared to the comparative example, the mechanical properties of the compositions in the examples, especially the tensile modulus and flexural modulus, are significantly improved, and the heat distortion temperature (HDT) is also significantly increased. Third, in Comparative Example 1, the content of 2,4'-diphenylmethane diisocyanate in the isocyanate component is too high, resulting in low curing reactivity of the composition, leading to low curing degree and poor mechanical properties. Fourth, no polymerization inhibitor was introduced in Comparative Example 3, so the exothermic peak temperature is much higher than that in the examples, and the operating time is shorter.
[0067] Example 4: Preparation of polyurethane composite material
[0068] The composite material was prepared by vacuum injection molding. First, the reinforcing material (glass fiber fabric) was laid in the mold, and a negative pressure environment was formed by a vacuum bag. The mold temperature was controlled at 25°C. Then, the polyurethane matrix resin material prepared in step 4 of Example 1 was introduced into the mold to fully impregnate the glass fiber fabric. Then, the temperature was raised to 50°C and cured for 1 hour. The temperature was then raised to 70°C and cured for 2 hours to complete the preparation of the polyurethane composite material.
[0069] Example 5: Preparation of polyurethane composite materials
[0070] The composite material was prepared by vacuum injection molding. First, the reinforcing material (glass fiber fabric) was laid in the mold, and a negative pressure environment was formed by a vacuum bag. The mold temperature was controlled at 25°C. Then, the polyurethane matrix resin material prepared in step 4 of Example 2 was introduced into the mold to fully impregnate the glass fiber fabric. Then, the temperature was raised to 50°C and cured for 1 hour. The temperature was then raised to 75°C and cured for 2 hours to complete the preparation of the polyurethane composite material.
[0071] Table 3. Molding and performance data of polyurethane composite materials
[0072] project Example 4 Example 5 Pre-curing temperature (°C) 50 50 Post-curing temperature (°C) 75 70 Tensile strength (MPa) 1260 1202 Tensile modulus (GPa) 48.1 47.5 Interlaminar shear strength (MPa) 74 69
[0073] Note: The composite materials prepared in Examples 4 and 5, due to the use of the polyurethane resin matrix material prepared in Examples 1 and 2, firstly have lower viscosity and longer working time, resulting in better resin wetting of fibers and a higher degree of wetting; secondly, the resin's sensitivity to moisture is reduced, so defects such as bubbles will not be generated in the composite material; finally, the matrix resin contains trifunctional isocyanate, thus exhibiting higher strength and interfacial adhesion. Considering all these factors, the composite materials of the examples have higher tensile properties and interlaminar shear strength.
Claims
1. A polyurethane resin matrix material for composite materials, characterized in that, The polyurethane resin matrix material is prepared by a polyurethane composition comprising: A) Isocyanate component, wherein the isocyanate component comprises diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate, wherein the isocyanate component contains 4-28 wt% of 2,4'-diphenylmethane diisocyanate and 12-27 wt% of dimethylene triphenyl triisocyanate. B) Organic polyol components; C) (Meth)acrylate components that have reactive active hydrogen atoms that resonate with isocyanate groups; D) Redox system, including initiator D1), catalyst D2), and polymerization inhibitor D3; The content of component A is 36-55 wt%, the content of component B is 24-35 wt%, and the content of component C is 15-39 wt%, calculated based on the total mass of the polyurethane matrix material as 100 wt%. The amount of initiator D1 is 0.1-1.1 wt% of the total mass of the polyurethane matrix material, the amount of catalyst D2 is 10-100 ppm of the total mass of the polyurethane matrix material, and the amount of polymerization inhibitor D3 is 40-600 ppm of the total mass of the polyurethane matrix material.
2. The polyurethane resin matrix material according to claim 1, characterized in that, Component B) is selected from one or more of polyether polyols, polyester polyols, or small molecule polyols.
3. The polyurethane resin matrix material according to claim 2, characterized in that, The organic polyol component contains polyether polyols with a molecular weight of 120-500, a functionality of 2-4, and a hydroxyl value of 100-600 mgKOH / g.
4. The polyurethane resin matrix material according to any one of claims 1-3, characterized in that, Component C) is selected from one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.
5. The polyurethane resin matrix material according to claim 1, characterized in that, The D1) is selected from one or more peroxide initiators.
6. The polyurethane resin matrix material according to claim 1, characterized in that, The D2) is selected from one or more organometallic compounds of copper, potassium, calcium, cobalt, and sodium.
7. The polyurethane resin matrix material according to claim 6, characterized in that, The D2) is selected from cobalt metal isooctanoate or cycloalkanoate.
8. The polyurethane resin matrix material according to claim 1, characterized in that, The D3 is selected from one or more of quinone and phenolic polymerization inhibitors.
9. A polyurethane resin matrix material according to any one of claims 1-8 for use in the manufacture of liquid molding composite materials.
10. A liquid molding composite material, characterized in that, It includes the polyurethane resin matrix material and reinforcing material as described in any one of claims 1-8; the mass ratio of the matrix material to the reinforcing material is 1:(1.5-5).
11. The composite material according to claim 10, characterized in that, The reinforcing material is selected from one or more combinations of glass fiber, carbon fiber, carbon nanotube, graphene, aramid fiber, natural fiber, ultra-high molecular weight polyethylene fiber, boron fiber, silicon carbide fiber, polyester fiber, nylon fiber, basalt fiber, and whiskers.
12. The composite material according to claim 10, characterized in that, The liquid molding composite material is prepared by resin transfer molding (RTM), wet compression molding (WCM), filament winding, pultrusion, or vacuum injection molding.
13. The composite material according to claim 12, characterized in that, During the liquid molding process, the curing temperature is 40-100℃ and the curing time is 2h-7h.