Organosilicon modified polyurethane polystyrene foam as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to organic silicon modified polyurethane polystyrene foam as well as a preparation method and application thereof. The polystyrene foam comprises a component A and a component B, the component A is prepared from 40 to 60 parts of polyethylene oxide polyol, 25 to 35 parts of cashew nut shell oil polyol, 15 to 25 parts of castor oil modified polyol, 5 to 10 parts of modified resin A, 18 to 22 parts of flame retardant filler, 0.5 to 1.5 parts of foam stabilizer, 0.1 to 0.2 part of catalyst and 0.4 to 0.9 part of pure water; the modified resin A is organic silicon modified resin which contains active amido and has alkoxy at the tail end; and the component B comprises the following components in parts by weight: 75-85 parts of polymerized MDI and 15-25 parts of prepolymer A. According to the invention, an organic silicon chain segment is connected into a polyurethane network in a chemical bond manner, so that high tensile strength and high bonding strength are maintained while the elongation at break is improved, and the technical problem that the performance of the polyurethane polystyrene foam is difficult to consider at the same time is solved.

Description

Technical Field

[0001] This invention relates to an organosilicon-modified polyurethane foam, its preparation method, and its application, belonging to the field of polymer materials technology. Background Technology

[0002] Polyurethane foam, as an important engineering material, is widely used for filling, sealing, and bonding in fields such as construction, automobiles, and aerospace. However, this material has long faced a key technical contradiction in practical applications: if its toughness and elongation are improved by adjusting the formula, it often leads to a decrease in material strength and a weakening of adhesive performance; conversely, if efforts are made to enhance its adhesive strength and rigidity, it usually causes material embrittlement, resulting in a significant reduction in elongation.

[0003] In existing technologies, plasticizers or the proportion of flexible segments are often added to improve toughness. However, these methods often significantly reduce the material's mechanical strength, heat resistance, and adhesive properties. On the other hand, simply increasing the crosslinking density to enhance adhesive strength inevitably leads to increased material brittleness, affecting its tolerance and service life under actual working conditions. This constraint between properties severely limits the further promotion of polyurethane foam in high-end and high-reliability applications.

[0004] Therefore, how to improve the toughness of materials while effectively maintaining their strength and adhesion properties, and avoid the performance trade-off problem common in traditional methods, has become a technical challenge that urgently needs to be overcome in this field. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing an organosilicon-modified polyurethane foam, its preparation method, and its applications.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides an organosilicon-modified polyurethane foam, comprising component A and component B; Component A comprises the following raw materials in parts by weight: 40-60 parts of polyethylene oxide polyol, 25-35 parts of cashew nut shell oil polyol, 15-25 parts of castor oil modified polyol, 5-10 parts of modified resin A, 18-22 parts of flame retardant filler, 0.5-1.5 parts of foam stabilizer, 0.1-0.2 parts of catalyst, and 0.4-0.9 parts of pure water; The modified resin A is an organosilicon modified resin containing active amine groups and terminal alkoxy groups, and has the general structural formula shown in formula (I):

[0007] Formula (I); Where n ranges from 30 to 50; R is C12 ~C 18 Alkyl groups; Component B comprises the following raw materials in parts by weight: 75-85 parts of polymeric MDI and 15-25 parts of prepolymer A; The prepolymer A is a polyurethane prepolymer with an NCO content of 16.0 ± 0.3%.

[0008] Based on the above technical solution, the present invention can also be improved as follows: Furthermore, the hydroxyl value of the polyoxyethylene polyol is 200–250 mgKOH / g.

[0009] Furthermore, the number-average molecular weight of the cashew nut shell oil polyol is 1000-1500.

[0010] Furthermore, the castor oil-modified polyol has three functions and a hydroxyl value of 450–500 mg KOH / g.

[0011] Furthermore, the modified resin A is prepared by ring-opening polymerization of amino silicone oil and long-chain alkyl glycidyl ether.

[0012] Furthermore, the amino silicone oil is a bis(3-aminopropyl)-terminated polydimethylsiloxane, which has the following structure: ; The value of n ranges from 30 to 50.

[0013] Furthermore, the long-chain alkyl glycidyl ether has the following structure: ; Where R is C 12 ~C 18 alkyl Furthermore, the preparation method of the modified resin A includes: reacting the amino silicone oil with the long-chain alkyl glycidyl ether at 70-80°C for 2-3 hours, then raising the temperature to 100-110°C, continuing the reaction under vacuum for 1.5-2 hours, and finally removing excess long-chain alkyl glycidyl ether by vacuum distillation.

[0014] Furthermore, the molar ratio of the long-chain alkyl glycidyl ether to the amino silicone oil is 2.1:1 to 2.2:1, the number average molecular weight of the amino silicone oil is 1500 to 2500, and the number average molecular weight of the long-chain alkyl glycidyl ether is 250 to 300.

[0015] Furthermore, the prepolymer A is prepared by reacting polyether diol with MDI-50, wherein the number average molecular weight of the polyether diol is 3000-5000.

[0016] Furthermore, the preparation method of the prepolymer A includes: heating the polyether diol to 100-110°C, dehydrating it under vacuum for 1-1.5 hours, cooling it to 40-50°C, adding MDI-50, and reacting it at 75-85°C until the NCO content of the product reaches 16.0±0.3%.

[0017] Furthermore, the mixing volume ratio of component A to component B is 1.95:1 to 2:1.

[0018] Furthermore, the flame retardant filler is selected from intumescent nitrogen-phosphorus flame retardants, preferably CF-IFR380 from Changfeng Chemical.

[0019] Furthermore, the foam stabilizer is selected from silicone-based foam stabilizers, preferably Dow Chemical's DC6070.

[0020] Furthermore, the catalyst is selected from amine catalysts, preferably triethylenediamine, such as Covestro's A33.

[0021] Secondly, the present invention provides a method for preparing the organosilicon-modified polyurethane foam as described above, comprising the following steps: Preparation of component A: Polyethylene oxide polyol, cashew nut shell oil polyol, castor oil modified polyol, modified resin A, flame retardant filler, foam stabilizer, and catalyst are stirred and dehydrated under vacuum conditions, then the vacuum is released, pure water is added and stirring is continued to obtain component A; Preparation of component B: Preheat the polymerized MDI, add prepolymer A, and stir until homogeneous to obtain component B; The components A and B are mixed using a metering and mixing device.

[0022] Thirdly, the present invention provides an application of the silicone-modified polyurethane foam as described above, mainly used in the sealing, shock absorption or battery pack encapsulation of transportation vehicles, or in the sealing of joints in building curtain walls or prefabricated buildings.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: I. Excellent Balance of Toughness and Strength: By modifying resin A, the flexible segments of silicone oil are introduced into the polyurethane network through chemical bonds, constructing an effective "rigid phase-flexible phase" microphase separation structure. Under external force, the flexible phase can effectively induce energy dissipation mechanisms such as crazes and shear bands, significantly increasing the elongation at break of the material to 25% or more. At the same time, the reinforcing effect of the rigid phase and urea bonds ensures that the tensile strength is maintained above 2.0 MPa, successfully resolving the performance contradiction of traditional technologies.

[0024] II. High Strength and Broad-Spectrum Adhesion: The active amine groups in modified resin A react with isocyanate to generate a large number of urea bonds. These urea bonds can form dense intermolecular hydrogen bonds, greatly enhancing the cohesive strength of the material. At the same time, the amine groups and urea bonds have strong interactions with the surfaces of various substrates, thus achieving high-strength adhesion (adhesion strength ≥ 2.0 MPa) to various materials such as aluminum plates, PET films, and epoxy coatings, with an adhesion grade of 0.

[0025] III. Excellent Overall Performance: While achieving high-toughness and high-strength adhesion, the flame retardant fillers in the formula ensure that the material meets the UL94-V0 flame retardant standard, satisfying stringent safety requirements. The synergistic effect of the components also gives the product good storage stability, workability, and weather resistance.

[0026] IV. Broad Application Prospects: The excellent comprehensive performance of this invention makes it particularly suitable for fields with extremely demanding requirements for the performance of sealing materials, such as sealing and buffering of new energy vehicle battery packs, shock absorption and sealing of high-speed rail carriages, and long-term sealing of dynamic joints in prefabricated buildings, etc., which has significant market value. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available conventional products. Unless otherwise specified, all parts are by weight.

[0028] Example 1 Preparation of modified resin A: In a dry reactor equipped with a stirrer, thermometer, nitrogen inlet pipe, and condenser, 2000 g of bis(3-aminopropyl)-terminated polydimethylsiloxane (molecular weight 2000) was added, and nitrogen was introduced for protection. Under stirring, 622 g of C15-alkyl glycidyl ether (number average molecular weight 290) was slowly added, with a molar ratio of long-chain alkyl glycidyl ether to bis(3-aminopropyl)-terminated polydimethylsiloxane of approximately 2.2:1. The reaction mixture was heated to 75°C and reacted at this temperature for 2.5 hours. Then, the temperature was increased to 105°C, and the system pressure was reduced to -0.098 MPa by turning on the vacuum pump, and the reaction continued for 1.8 hours. After the reaction was completed, unreacted excess C15-alkyl glycidyl ether was removed by distillation under reduced pressure to obtain modified resin A.

[0029] Preparation of prepolymer A: In a drying reactor, 500g of DL-4000D (Lanxing Dongda Chemical) was added, and the temperature was raised to 105℃. Dehydration was carried out under a vacuum of -0.098MPa for 1.5 hours. The temperature was then lowered to below 45℃, and 545g of MDI-50 (Wanhua Chemical) was added. After stirring thoroughly, the temperature was raised to 75℃, and the reaction was carried out at this temperature for 3.5 hours. The NCO content of the system was monitored using di-n-butylamine titration. When the NCO content reached 16.0%, the reaction was stopped, yielding prepolymer A.

[0030] Preparation of expanding foam: Preparation of Component A: 50 parts of DIO-260 (hydroxyl value 225 mgKOH / g, Tyronde), 30 parts of cashew nut shell oil polyol (molecular weight 1000, Cardley Chemical), 20 parts of castor oil modified polyol (functionality 3, hydroxyl value 475 mgKOH / g, Anshan Chuangye Biotechnology), 8 parts of modified resin A, 20 parts of flame retardant (Changfeng Chemical, CF-IFR380), 1.0 part of foaming agent (Dow Chemical, DC6070), and 0.15 parts of catalyst A33 (Covestro) were added to a vacuum planetary mixer. The mixture was stirred and dehydrated at 48℃ and -0.09MPa vacuum for 2 hours. After the vacuum was turned off and atmospheric pressure was restored, 0.7 parts of pure water were added, and stirring continued for 0.5 hours to obtain Component A.

[0031] Preparation of component B: 80 parts of polymeric MDI (Wanhua PM-200) were preheated to 40°C, and 20 parts of prepolymer A were added. The mixture was stirred at low speed for 1.5 hours until homogeneous to obtain component B.

[0032] During construction, a two-component metering and mixing device is used to mix component A and component B at a volume ratio of 2:1.

[0033] Example 2 Unlike Example 1, the formulation of component A was adjusted to: 40 parts of polyethylene oxide polyol (Tairund, DIO-260), 35 parts of cashew nut shell oil polyol (molecular weight 1000, Cardley Chemical), 25 parts of castor oil modified polyol (functionality 3, hydroxyl value 475mgKOH / g, Anshan Chuangye Biotechnology), 10 parts of modified resin A, 20 parts of flame retardant filler (Changfeng Chemical, CF-IFR380), 1.0 part of foam stabilizer (Dow Chemical, DC6070), 0.15 parts of catalyst (Covestro A33), and 0.7 parts of water.

[0034] The formulation of component B is the same as in Example 1.

[0035] The volume ratio of component A to component B is 1.95:1. The preparation and mixing processes of components A and B are the same as in Example 1, and will not be repeated here.

[0036] Example 3 Unlike Example 1, the formulation of component A was adjusted to: 60 parts of polyethylene oxide polyol (Tairund, DIO-260), 25 parts of cashew nut shell oil polyol (molecular weight 1000, Cardley Chemical), 15 parts of castor oil modified polyol (functionality 3, hydroxyl value 475mgKOH / g, Anshan Chuangye Biotechnology), 5 parts of modified resin A, 20 parts of flame retardant filler (Changfeng Chemical, CF-IFR380), 1.0 part of foam stabilizer (Dow Chemical, DC6070), 0.15 parts of catalyst (Covestro A33), and 0.7 parts of water.

[0037] The formulation of component B is the same as in Example 1.

[0038] The volume ratio of component A to component B is 1.98:1. The preparation and mixing processes of components A and B are the same as in Example 1, and will not be repeated here.

[0039] Comparative Example 1 The difference between this comparative example and Example 1 is that the amount of C15-alkyl glycidyl ether used to prepare modified resin A is reduced to 603 g (the molar ratio with bis(3-aminopropyl)-terminated polydimethylsiloxane is approximately 2.08:1). Everything else is the same as in Example 1.

[0040] Comparative Example 2 The difference between this comparative example and Example 1 is that the amount of C15-alkyl glycidyl ether used to prepare modified resin A is increased to 644 g (the molar ratio of C15-alkyl glycidyl ether to bis(3-aminopropyl)-terminated polydimethylsiloxane is approximately 2.24:1). Everything else is the same as in Example 1.

[0041] Comparative Example 3 The difference between this comparative example and Example 1 is that no modified resin A was added to component A, while the other components and their amounts remained unchanged.

[0042] Performance testing Component A and component B of Examples 1-3 and Comparative Examples 1-3 were mixed in a specific ratio to prepare sample pieces. These samples were then freely foamed and cured at room temperature for 7 days to prepare standard test strips. Performance tests were conducted according to the following standards: Tensile properties: GB / T 528-2009; Bond strength: GB / T 16777-2008 Adhesion: Tested according to GB / T 9286-1998.

[0043] The test results are shown in Table 1: Table 1 Performance data of the embodiments and comparative examples

[0044] The data in the table above shows that: The foamed adhesives prepared in Examples 1-3 of this invention maintain high tensile strength (2.03-2.21 MPa) while exhibiting elongation at break exceeding 25%, achieving an excellent balance between toughness and strength. In contrast, Comparative Example 3 (unmodified resin A) has a high tensile strength (3.15 MPa), but an extremely low elongation at break (5.45%), resulting in high brittleness.

[0045] The bonding strength of the present invention was significantly improved, demonstrating the key role of the amine groups in modified resin A in improving bonding performance.

[0046] In Comparative Examples 1 and 2, because the molar ratio of raw materials deviated from the preferred range of this invention (2.1–2.2:1) during the synthesis of modified resin A, the structure (number of amino groups and chain segment length) of the product was not optimal. Consequently, the performance of the final foamed adhesive (especially the elongation at break and bond strength) was significantly lower than that of the embodiments of this invention, but still superior to Comparative Example 3 without any additives. This demonstrates the necessity of controlling the synthesis process of modified resin A in this invention.

[0047] In summary, this invention, through the synergistic effect of modified resin A and its polyol / isocyanate system, successfully obtained a high-toughness polyurethane foam with comprehensive performance superior to existing technologies.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 silicone-modified polyurethane foam, characterized in that, Includes component A and component B; Component A comprises the following raw materials in parts by weight: 40-60 parts of polyethylene oxide polyol, 25-35 parts of cashew nut shell oil polyol, 15-25 parts of castor oil modified polyol, 5-10 parts of modified resin A, 18-22 parts of flame retardant filler, 0.5-1.5 parts of foam stabilizer, 0.1-0.2 parts of catalyst, and 0.4-0.9 parts of pure water; The modified resin A is an organosilicon modified resin containing active amine groups and terminal alkoxy groups, and has the general structural formula shown in formula (I): Formula (I); Where n ranges from 30 to 50; R is C 12 ~C 18 Alkyl groups; Component B comprises the following raw materials in parts by weight: 75-85 parts of polymeric MDI and 15-25 parts of prepolymer A; The prepolymer A is a polyurethane prepolymer with an NCO content of 16.0 ± 0.3%.

2. The silicone-modified polyurethane foam according to claim 1, characterized in that, The modified resin A is prepared by ring-opening polymerization of amino silicone oil and long-chain alkyl glycidyl ether.

3. The silicone-modified polyurethane foam according to claim 2, characterized in that, The preparation method of the modified resin A includes: reacting the amino silicone oil with the long-chain alkyl glycidyl ether at 70-80°C for 2-3 hours, then raising the temperature to 100-110°C and continuing the reaction under vacuum for 1.5-2 hours, and finally removing the excess long-chain alkyl glycidyl ether by vacuum distillation.

4. The silicone-modified polyurethane foam according to claim 3, characterized in that, The molar ratio of the long-chain alkyl glycidyl ether to the amino silicone oil is 2.1:1 to 2.2:1, the number average molecular weight of the amino silicone oil is 1500 to 2500, and the number average molecular weight of the long-chain alkyl glycidyl ether is 250 to 300.

5. The silicone-modified polyurethane foam according to claim 1, characterized in that, The prepolymer A is prepared by reacting polyether diol with MDI-50, wherein the number average molecular weight of the polyether diol is 3000-5000.

6. The silicone-modified polyurethane foam according to claim 5, characterized in that, The preparation method of the prepolymer A includes: heating the polyether diol to 100-110°C, dehydrating it under vacuum for 1-1.5 hours, cooling it to 40-50°C, adding MDI-50, and reacting it at 75-85°C until the NCO content of the product reaches 16.0±0.3%.

7. The silicone-modified polyurethane foam according to any one of claims 1 to 6, characterized in that, The volume ratio of component A to component B is 1.95:1 to 2:

1.

8. The silicone-modified polyurethane foam according to claim 1, characterized in that, The flame retardant filler is selected from intumescent nitrogen-phosphorus flame retardants; The foam leveler is selected from silicone-based foam levelers; The catalyst is selected from amine catalysts.

9. A method for preparing an organosilicon-modified polyurethane foam as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Preparation of component A: Polyethylene oxide polyol, cashew nut shell oil polyol, castor oil modified polyol, modified resin A, flame retardant filler, foam stabilizer, and catalyst are stirred and dehydrated under vacuum conditions, then the vacuum is released, pure water is added and stirring is continued to obtain component A; Preparation of component B: Preheat the polymerized MDI, add prepolymer A, and stir until homogeneous to obtain component B; The components A and B are mixed using a metering and mixing device.

10. The application of an organosilicon-modified polyurethane foam as described in any one of claims 1 to 8, characterized in that, It is used in sealing, shock absorption, or battery pack encapsulation of transportation vehicles, or in sealing joints of building curtain walls or prefabricated buildings.

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