Polyurethane super-hydrophobic foam composite material for packaging and preparation method thereof

Abstract

The present invention relates to the technical field of polyurethane production, specifically to a polyurethane super-hydrophobic foam composition for encapsulation and a preparation method thereof. The polyurethane super-hydrophobic foam composition for encapsulation is prepared by reacting component A and component B in a mass ratio of 100: (31.7~46.5); wherein component A includes high molecular weight and high activity polyether polyol X, polymer polyol, chain extender, cross-linking agent, organometallic catalyst, tertiary amine catalyst, foam stabilizer, foaming agent, flame retardant, inorganic filler, etc., and component B is an isocyanate modified by high functionality polyether polyol Y. The present invention improves the internal soft segment structure and chemical crosslinking density of polyurethane foam by introducing ester bonds, rigid benzene ring groups, and Si-O-Si segments into polyether polyol molecular segments, and the prepared polyurethane super-hydrophobic foam not only has excellent hydrophobicity and high temperature resistance, but also has low density and good mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane production, in particular to a polyurethane super-hydrophobic foam composite material for encapsulation and a preparation method thereof. Background Art

[0002] In today's era of rapid technological development, precision instruments and meters have penetrated into all aspects of our lives, and packaging materials play a vital role in ensuring the long-term stable operation of electronic equipment. These high-tech products have extremely high requirements for the packaging of electronic components. Once damaged, the consequences may be disastrous. For example, the power batteries of new energy vehicles are generally installed at a relatively low position and exposed to a relatively open environment. Coastal and rainy areas are often attacked by rain and typhoons. The power batteries may have internal water ingress, which in turn leads to short circuits and electrolysis, causing fire and explosion accidents. Under high temperature conditions, the leakage of the battery will increase rapidly, and the heat will also increase, increasing the risk of battery explosion. As people's requirements for safety, environmental protection, and comfort become higher and higher, high temperature and humidity resistance, hydrophobicity, and lightweight have become new needs in the electronic component packaging industry.

[0003] Chinese patent CN117431032A, published on January 23, 2024, discloses a foamed polyurethane sealant composition for batteries and its preparation method. The composition is composed of a mixture of component A and component B. Component A is polyether polyol, flame retardant polyether polyol, polyester ether, crosslinking agent polyether, chain extender, flame retardant, foaming agent, foam stabilizer and composite catalyst. Component B is bio-based polyether polyol and liquefied MDI. The battery sealant product prepared by the composition is light in weight, excellent in mechanical properties, good in hydrolysis resistance and hydrophobicity. However, the density, hydrophobicity and heat resistance of the foamed polyurethane sealant obtained by the preparation method need to be further improved.

[0004] Chinese patent CN117050294A, published on November 14, 2023, discloses a method for preparing a super-hydrophobic polyether polyol, comprising the steps of: a) polymerization reaction: using a polyhydroxy compound as an initiator, under the action of a catalyst, and carrying out a ring-opening polymerization reaction with an epoxide, after the reaction is completed, aging, degassing, and obtaining polyether polyol A; b) esterification modification: under the action of a catalyst, polyether polyol A is esterified with a hydrophobic long-chain fatty acid to obtain a super-hydrophobic polyether polyol. The functionality of the super-hydrophobic polyether polyol prepared by the invention is ≥2.3, and the number average molecular weight is 3000~16000g / mol, but the method requires the polyether polyol to be esterified, the esterification reaction cycle is long, the preparation process is complicated, and the terminal hydroxyl groups of the polyether polyol are basically secondary hydroxyl groups, which are not suitable for preparing polyurethane foams.

[0005] Chinese patent CN113105616A, published on July 13, 2021, discloses a method for preparing a hydrophobic polyether polyol, using one or more hydrophobic initiators selected from terminal hydroxy fatty diols, bisphenol A, bisphenol F, and terminal hydroxy polysiloxane as initiators, using alkali metals or DMC as catalysts, and mixing with propylene oxide and one or two of butylene oxide and 1,2-epoxypentane as hydrophobic polymerization monomers for polymerization reaction to obtain a crude polymer of polyether polyol, and then refining to obtain a hydrophobic polyether polyol. The terminal hydroxyl groups of the hydrophobic polyether polyol prepared by this invention are also secondary hydroxyl groups, which are not suitable for the preparation of polyurethane foams. Summary of the invention

[0006] In view of the above deficiencies in the prior art, the purpose of the present invention is to provide a polyurethane super-hydrophobic foam composition for encapsulation, the molecular structure of the polyether polyol is designed, and rigid benzene ring groups, Si-O-Si segments, and ester bonds are introduced into the molecular chain segments, which can be used in polyurethane foam to significantly improve the heat resistance and hydrophobicity of the product, and the storage stability is high; and the product density is low, and the core density is 0.15~0.3g / cm 3 , meeting the requirements of lightweight development.

[0007] Another object of the present invention is to provide a method for preparing a polyurethane super-hydrophobic foam composite material for encapsulation, which has simple process, high production efficiency and is suitable for industrial production.

[0008] The present invention is achieved by adopting the following technical solutions:

[0009] The polyurethane super-hydrophobic foam composite material for encapsulation is prepared by reacting component A and component B in a mass ratio of 100:(31.7-46.5);

[0010] Wherein, the component A is composed of the following raw materials in parts by weight: polyether polyol X: 70-95 parts, polymer polyol: 5-30 parts, chain extender: 10-20 parts, cross-linking agent: 1-3 parts, organic metal catalyst: 0.04-0.12 parts, tertiary amine catalyst: 0.5-1.5 parts, foam stabilizer: 0.2-1.0 parts, foaming agent: 8.2-20.1 parts, flame retardant: 10-20 parts, inorganic filler: 2-10 parts;

[0011] The component B is an isocyanate modified by polyether polyol Y, with an isocyanate content of 24-28%, and is composed of the following raw materials in parts by weight: polyether polyol Y: 15.5-25.9 parts, pure MDI: 68.1-79.1 parts; MDI-50: 4.7-6.9 parts, polymethylene polyphenyl polyisocyanate: 0.5-0.8 parts;

[0012] The polyether polyol X in the component A is a high molecular weight and high activity polyether polyol with an average functionality of 2.7 to 5.0; the organic metal catalyst in the component A is a tin catalyst; the tertiary amine catalyst in the component A is one of N-methyldicyclohexylamine, pentamethyldiethylenetriamine, N,N-bis(dimethylaminopropyl)isopropanolamine and N,N-(dimethylaminopropyl)diisopropanolamine.

[0013] The high molecular weight and high activity polyether polyol in the A component has a number average molecular weight of 4000-12000 g / mol, a primary hydroxyl content of ≥70%, and an ester bond, a rigid benzene ring group, and a Si-O-Si segment in the polyether segment. It is prepared by ring-opening polymerization of castor oil, a benzene ring-containing initiator, and an initiator with a functionality of 4 or more as a composite initiator, and propylene oxide and cyclosiloxane in a mass ratio of (5.3-17.2):1 under the action of a phosphazene catalyst and a Lewis acid catalyst. The mass ratio of castor oil, a benzene ring-containing initiator, and an initiator with a functionality of 4 or more is (3.68-12):1:(0.2-2.28).

[0014] The benzene ring-containing initiator of the polyether polyol X is one or a mixture of two of bisphenol A, bisphenol fluorene, tetrabromobisphenol A, tetrachlorobisphenol A, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol M), α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene (bisphenol P); the initiator with a functionality of 4 or more is one or a mixture of two of pentaerythritol, erythritol, xylitol, sorbitol, mannitol, and lactitol.

[0015] The cyclosiloxane is a phenyl-containing cyclosiloxane, and the amount used is 2-20% of the total mass of the raw materials of the reaction system. The cyclosiloxane is preferably one of trimethyltriphenylcyclotrisiloxane, hexaphenylcyclotrisiloxane, bisphenyldimethylcyclosiloxane, tetramethyltetraphenylcyclotetrasiloxane or heptamethylphenylcyclotetrasiloxane.

[0016] Preferably, the phosphazene catalyst is one of phosphazene salt, phosphazene base and phosphazene oxide, and the amount used is 0.05-0.10% of the total mass of the raw materials of the reaction system. The Lewis acid catalyst is an alkyl borane or a borate, preferably one of tris(pentafluorophenyl)borane, triphenylborane, triethylboryl lithium and triethylboryl tetramethyl ammonium salt, and the amount used is 80-120 ppm of the total mass of the raw materials of the reaction system.

[0017] Preferably, the preparation method of the polyether polyol X adopts a conventional preparation method in the art, and the specific method is: adding an initiator and a phosphazene catalyst to a pressure-resistant reactor and mixing, nitrogen replacement, so that the oxygen content in the reactor is less than 50 ppm, heating to 90-105° C., vacuum dehydration for 1-2 hours, continuously dropping propylene oxide and cyclosiloxane at 90-105° C. for ring-opening polymerization, continuing the internal pressure reaction after the reaction is completed until the pressure no longer decreases, vacuuming to remove unreacted alkylene oxide monomers and small molecule by-products, acid-base neutralization to remove the catalyst, and obtaining a polyether intermediate, and then adding the intermediate polyether and a Lewis acid catalyst to a pressure-resistant reactor and mixing, continuously dropping propylene oxide at 80-100° C. for ring-opening polymerization, continuing the internal pressure reaction after the reaction is completed until the pressure no longer decreases, vacuuming to remove unreacted alkylene oxide monomers and small molecule by-products, and obtaining polyether polyol X.

[0018] The polymer polyol in the A component is a flame retardant polymer polyol, preferably one of YB-3081, YB-3082 and YB-3083 produced by Jiangyin Youbang Chemical Co., Ltd.

[0019] The crosslinking agent in the component A is prepared by ring-opening polymerization of propylene oxide and / or ethylene oxide with a small molecule alcohol or a small molecule amine having trifunctional or higher functions as an initiator, and the molar ratio of the initiator to the alkylene oxide is 1:(1-30), preferably, the molar ratio of the initiator to the alkylene oxide is 1:(4-15). Preferably, the small molecule alcohol and small molecule amine initiators are one or a mixture of two of glycerol, trimethylolpropane, erythritol, triethanolamine, and xylitol. Such crosslinking agents are used in polyurethane foams to improve the resilience of the product and produce a dense epidermis.

[0020] The chain extender in the A component is an alcohol chain extender. Preferably, one or a mixture of two of TCD tricyclic diol, 3-methyl-1,5-pentanediol, hydroquinone dihydroxyethyl ether (HQEE), 1,4-butanediol, ethylene glycol, and bisphenol A dihydroxyethyl ether is selected. The products made of such chain extenders have excellent adhesion, heat resistance, and weather resistance. The flame retardant in the A component is one of TCPP, TCEP, DMMP, and TEP.

[0021] The tin catalyst is preferably one of dioctyltin dilaurate, bis(dodecylthio)dimethyltin, dimethyltin mercaptan, and dioctyltin dioctanoate.

[0022] The foam stabilizer in the A component is one or a mixture of two of DC193, DC3042, DC3043 of Air Products and Chemicals, and L1501, L3003 of Momentive.

[0023] The foaming agent in the component A comprises a mixture of a physical foaming agent and a chemical foaming agent, the mass ratio of the physical foaming agent to the chemical foaming agent is (40-200):1, the physical foaming agent is one of difluoromonochloroethane, dichloroethane, and butane, and the chemical foaming agent is water.

[0024] The inorganic filler in the component A is one or a mixture of two of fumed silica, sericite, calcium sulfate and glass fiber.

[0025] The polyether polyol Y in the B component has a functionality of 6, a number average molecular weight of 6000-12000 g / mol, and a primary hydroxyl content of ≥70%. It is prepared by ring-opening polymerization of sorbitol, mannitol, dipentaerythritol and propylene oxide under the action of a Lewis acid catalyst, or by ring-opening polymerization of sorbitol, mannitol, dipentaerythritol, propylene oxide and ethylene oxide under the action of an alkali metal catalyst and / or a phosphazene catalyst; the preparation method adopts a conventional preparation method in the art, and is not particularly limited. For example, sorbitol is used as an initiator and tri(pentafluorophenyl)borane is used as a catalyst to catalyze the ring-opening polymerization of propylene oxide to obtain the product, wherein the concentration of the tri(pentafluorophenyl)borane catalyst is 80-120ppm, and the mass ratio of sorbitol to propylene oxide is 1:(32-65); mannitol is used as an initiator and KOH is used as a catalyst to first catalyze the ring-opening polymerization of propylene oxide and then catalyze the ring-opening polymerization of ethylene oxide to obtain the product, wherein the concentration of the KOH catalyst is 0.2-0.3wt%, and the mass ratio of mannitol to propylene oxide and ethylene oxide is 1:(28.7-51.8):(3.3-13.2). The method adopts dipentaerythritol as an initiator and phosphazene salt as a catalyst, first catalyzes the ring-opening polymerization of propylene oxide, and then catalyzes the ring-opening polymerization of ethylene oxide to obtain the product, wherein the concentration of the phosphazene salt catalyst is 0.03-0.08wt%, and the mass ratio of dipentaerythritol to propylene oxide and ethylene oxide is 1:(20.25-36.7):(2.4-9.6).

[0026] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0027] 1) Preparation of component A: Add polyether polyol X and polymer polyol into a reaction kettle at 30-40°C and stir, then add chain extender, cross-linking agent, organic metal catalyst, tertiary amine catalyst, foam stabilizer, foaming agent, flame retardant, inorganic filler, rotate at 40-50 rpm, stir for 1-2 hours, and seal for storage;

[0028] 2) Preparation of component B: put polyether polyol Y into a reactor, stir and heat to 100-110°C, vacuum dehydrate and degas for 2-3 hours, cool to 40-50°C, add pure MDI and MDI-50, heat to 80-85°C and keep warm for 2-3 hours, add polymethylene polyphenyl isocyanate and stir for 30 minutes, take samples to test the -NCO content to be between 24-28wt%, cool down, discharge, and seal for storage;

[0029] 3) Place components A and B in corresponding tanks of a low-pressure pouring machine, keep the temperature at 25-35°C, quickly mix components A and B in proportion and pour them into a mold. Open the mold after 10-20 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) The polyurethane super-hydrophobic foam composition for encapsulation described in the present invention organically combines ester bonds, ether bonds, rigid benzene ring groups, and Si-O-Si segments in the polyether polyol molecular chain segments, which can significantly improve the high temperature resistance and hydrophobicity resistance of the polyurethane foam.

[0032] 2) The polyurethane super-hydrophobic foam composition for encapsulation described in the present invention, component A and component B adopt high-functionality, high-molecular-weight and high-activity polyether polyols, which can reduce the density of the product while ensuring that it still has high mechanical properties; the high polyether functionality and primary hydroxyl content give the formula system sufficient cross-linking curing speed and post-ripening speed, solve the problem of slow cross-linking curing and aging speed of polyurethane foam, and effectively improve the product's resistance to moisture and heat aging.

[0033] 3) The preparation method of the polyurethane super-hydrophobic foam composite material for encapsulation described in the present invention has simple process, convenient operation and high production efficiency.

[0034] 4) The present invention designs the molecular structure of polyether polyols, introduces rigid benzene ring groups, Si-O-Si segments, and ester bonds into the molecular chain segments, and can be used in polyurethane foam to significantly improve the heat resistance and hydrophobicity of the products, and has high storage stability; and the product has low density, with a core density of 0.15-0.3 g / cm 3 , meeting the requirements of lightweight development. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to the examples. The raw materials used in the examples, unless otherwise specified, are all commercially available conventional raw materials; the process methods used in the examples, unless otherwise specified, are all conventional methods in the art.

[0036] Some of the raw materials used in the examples are described as follows:

[0037] INOVOL F330N, Shandong INOVOL New Materials Co., Ltd. (functionality 3, number average molecular weight 5000, EO end-capped).

[0038] DG5411, Shandong Yinuowei Polyurethane Co., Ltd.

[0039] Polymethylene polyphenyl isocyanate: PM-100, Yantai Wanhua Polyurethane Co., Ltd.

[0040] Example 1

[0041] The preparation method of the polyether polyol X1 is:

[0042] S1: 115.1 kg of castor oil, 9.6 kg of bisphenol M, 17.4 kg of sorbitol, and 1.5 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 2 h. 600 kg of propylene oxide and 150 kg of hexaphenylcyclotrisiloxane were slowly added dropwise at 90° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.45 kg of phosphoric acid, 30 kg of water, and 0.9 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 1 was obtained.

[0043] S2: 894 kg of intermediate polyether polyol 1 and 0.20 kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 80°C after nitrogen replacement for 3 times. 1107 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X1 with a hydroxyl value of 27.4 mgKOH / g, a functionality of 3.9, a number average molecular weight of 7985 g / mol, and a primary hydroxyl content of 76.7%.

[0044] The preparation method of the polyether polyol Y1 is:

[0045] 51 kg of sorbitol was used as an initiator and 0.3 kg of tri(pentafluorophenyl)borane was used as a catalyst to catalyze the ring-opening polymerization of 2947 kg of propylene oxide. After sufficient reaction, unreacted polymerized monomers and small molecular substances were removed to obtain polyether polyol Y1 with a hydroxyl value of 31.9 mgKOH / g, a number average molecular weight of 10552 g / mol and a primary hydroxyl content of 77.2%.

[0046] Crosslinking agent 1 is a mixture of trimethylolpropane, propylene oxide and ethylene oxide prepared by ring-opening polymerization in a molar ratio of 1:4:4, with a molecular weight of 542 g / mol;

[0047] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0048] 1) Component A: Weigh 95kg of polyether polyol X1 and 5kg of YB-3081 respectively into a reactor at 30°C and stir, then add 1.5kg of crosslinker 1, 6kg of TCD tricyclic glycol, 9kg of ethylene glycol, 0.08kg of dioctyltin dilaurate, 1kg of N-methyldicyclohexylamine, 0.5kg of DC193, 0.15kg of water, 15kg of difluoromonochloroethane, 20kg of TCPP, and 8kg of fumed silica, keep the speed at 40 rpm, stir for 2h, mix thoroughly and evenly, and seal for storage;

[0049] 2) Component B: Add 23.8 kg of polyether polyol Y1 into a reactor, stir and heat to 100°C, vacuum dehydrate and degas for 3 hours, cool to 40°C, add 69.8 kg of pure MDI and 5.9 kg of MDI-50, heat to 85°C and keep warm for 3 hours, add 0.5 kg of PM-100 and stir for 30 minutes, take a sample and test the -NCO content to be 25.01 wt%, cool down, discharge, and seal for storage;

[0050] Components A and B are placed in corresponding tanks of a low-pressure casting machine, kept at 25° C., and components A and B are quickly mixed at a ratio of 100:46.5 and poured into a mold. The mold is opened after 10 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

[0051] Example 2

[0052] The preparation method of the polyether polyol X2 is:

[0053] S1: 138.4 kg of castor oil, 37.6 kg of bisphenol fluorene, 7.8 kg of pentaerythritol, and 1.4 kg of phosphazene base catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 105° C. for dehydration for 1 hour. 300 kg of propylene oxide and 100 kg of trimethyltriphenylcyclotrisiloxane were slowly added dropwise at 105° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.42 kg of phosphoric acid, 20 kg of water, and 0.6 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 2 was obtained.

[0054] S2: 585 kg of intermediate polyether polyol 2 and 0.18 kg of triphenylborane were added to a pressure reactor. The temperature was raised to 90°C after nitrogen replacement for 3 times. 1415 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X2, with a hydroxyl value of 25.3 mg KOH / g, a functionality of 2.7, a number average molecular weight of 5987 g / mol, and a primary hydroxyl content of 77.5%.

[0055] The preparation method of the polyether polyol Y2 is:

[0056] 90 kg of mannitol was used as an initiator and 7.5 kg of KOH was used as a catalyst to first catalyze the ring-opening polymerization of 2465 kg of propylene oxide and then catalyze the ring-opening polymerization of 450 kg of ethylene oxide. After sufficient reaction, unreacted polymerization monomers and small molecular substances were removed, and the catalyst was removed by acid-base neutralization to obtain polyether polyol Y2 with a hydroxyl value of 56.3 mg KOH / g, a number average molecular weight of 5979 g / mol, and a primary hydroxyl content of 74.5%.

[0057] Cross-linking agent 2 is prepared by ring-opening polymerization of erythritol and propylene oxide in a molar ratio of 1:12, and has a molecular weight of 818 g / mol.

[0058] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0059] 1) Component A: weigh 90kg of polyether polyol X2 and 10kg of YB-3082 respectively and put them into a reactor at 40°C and stir. Then add 3kg of crosslinker 2, 15kg of 3-methyl-1,5-pentanediol, 0.04kg of bis(dodecylthio)dimethyltin, 0.5kg of pentamethyldiethylenetriamine, 0.4kg of DC3042, 0.2kg of water, 18kg of ethylene dichloride, 15kg of DMMP and 10kg of sericite. Keep the speed at 50 rpm and stir for 1h. Mix well and seal for storage.

[0060] 2) Component B: Add 17.3 kg of polyether polyol Y2 into a reactor, stir and heat to 110°C, vacuum dehydrate and degas for 2 hours, cool to 50°C, add 75.2 kg of pure MDI and 6.9 kg of MDI-50, heat to 80°C and keep warm for 3 hours, add 0.6 kg of PM-100 and stir for 30 minutes, take a sample and test the -NCO content, which is 27.08 wt%, cool down, discharge, and seal for storage;

[0061] Components A and B are placed in corresponding tanks of a low-pressure pouring machine, kept at 35° C., and components A and B are quickly mixed at a ratio of 100:33.9 and poured into a mold. The mold is opened after 10 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

[0062] Example 3

[0063] The preparation method of the polyether polyol X3 is:

[0064] S1: 230.7 kg of castor oil, 36.2 kg of tetrachlorobisphenol A, 15.8 kg of mannitol, 7.5 kg of erythritol, and 1.0 kg of phosphazene oxide catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 100° C. for dehydration for 1 hour. 702 kg of propylene oxide and 200.5 kg of diphenyl dimethylcyclosiloxane were slowly added dropwise at 100° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.3 kg of phosphoric acid, 40 kg of water, and 1.2 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 3 was obtained.

[0065] S2: 1193kg of the intermediate polyether polyol 3 and 0.16kg of triethylboronphenyl lithium were added to a pressure reactor. The temperature was raised to 100°C after nitrogen replacement for 3 times. 811kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X3, which had a hydroxyl value of 46.4mgKOH / g, a functionality of 3.3, a number average molecular weight of 3990g / mol, and a primary hydroxyl content of 74.8%.

[0066] The preparation method of the polyether polyol Y3 is:

[0067] 83.7 kg of dipentaerythritol was used as an initiator and 0.36 kg of tri(pentafluorophenyl)borane was used as a catalyst to catalyze the ring-opening polymerization of 2916 kg of propylene oxide. After sufficient reaction, unreacted polymerized monomers and small molecular substances were removed to obtain polyether polyol Y3 with a hydroxyl value of 37.7 mgKOH / g, a number average molecular weight of 8928 g / mol and a primary hydroxyl content of 77.8%.

[0068] Cross-linking agent 3 was prepared by ring-opening polymerization of triethanolamine and ethylene oxide in a molar ratio of 1:4, and had a molecular weight of 325 g / mol.

[0069] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0070] 1) Component A: Weigh 80kg of polyether polyol X3 and 20kg of YB-3083 respectively into a reactor at 35°C and stir, then add 2.5kg of crosslinker 3, 8kg of 1,4-butanediol, 12kg of bisphenol A dihydroxyethyl ether, 0.1kg of dioctyltin dilaurate, 1.3kg of pentamethyldiethylenetriamine, 0.6kg of DC3043, 0.1kg of water, 20kg of butane, 13kg of TEP, and 2kg of calcium sulfate, keep the speed at 45 rpm, stir for 1.5h, mix well, and seal for storage;

[0071] 2) Component B: Add 20.7 kg of polyether polyol Y3 into a reactor, stir and heat to 105°C, vacuum dehydrate and degas for 2.5 hours, cool to 45°C, add 72.7 kg of pure MDI and 5.8 kg of MDI-50, heat to 82.5°C and keep warm for 2.5 hours, add 0.8 kg of PM-100 and stir for 30 minutes, take a sample and test the -NCO content, which is 26.02 wt%, cool down, discharge, and seal for storage;

[0072] Components A and B are placed in corresponding tanks of a low-pressure pouring machine, kept at 30°C, and components A and B are quickly mixed at a ratio of 100:38.6 and poured into a mold. The mold is opened after 10 minutes to obtain the polyurethane super-hydrophobic foam combination material for encapsulation.

[0073] Example 4

[0074] The preparation method of the polyether polyol X4 is:

[0075] S1: 73.4 kg of castor oil, 4.5 kg of bisphenol A, 10.7 kg of tetrabromobisphenol A, 12.0 kg of xylitol, and 1.7 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 1 hour. 1250 kg of propylene oxide and 250 kg of tetramethyltetraphenylcyclotetrasiloxane were slowly added dropwise at 95° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.51 kg of phosphoric acid, 43 kg of water, and 1.2 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 4 was obtained.

[0076] S2: 1602g of the intermediate polyether polyol 4 and 0.24g of triethylboronphenyl tetramethylammonium salt were added to a pressure reactor. The temperature was raised to 90°C after nitrogen replacement for 3 times, and 398g of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The reaction was vacuumed to remove the unreacted residual monomers to obtain the target polyether polyol X4, which had a hydroxyl value of 19.5mgKOH / g, a functionality of 3.48, a number average molecular weight of 10012g / mol, and a primary hydroxyl content of 73.2%.

[0077] The preparation method of the polyether polyol Y4 is:

[0078] 44.4 kg of sorbitol was used as an initiator and 6 kg of KOH was used as a catalyst to first catalyze the ring-opening polymerization of 244 kg of propylene oxide. After sufficient reaction, 0.9 kg of phosphazene catalyst was added to first catalyze the ring-opening polymerization of 2352 kg of propylene oxide and then catalyze the ring-opening polymerization of 360 kg of ethylene oxide. After sufficient reaction, unreacted polymerized monomers and small molecular substances were removed, and the catalyst was removed by acid-base neutralization to obtain polyether polyol Y4 with a hydroxyl value of 28.5 mg KOH / g, a number average molecular weight of 11810 g / mol, and a primary hydroxyl content of 75.7%.

[0079] Cross-linking agent 4 is prepared by ring-opening polymerization of xylitol with propylene oxide and then with ethylene oxide in a molar ratio of 1:5:10, and has a molecular weight of 618 g / mol.

[0080] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0081] 1) Component A: weigh 70kg of polyether polyol X4 and 30kg of YB-3083 respectively and put them into a reactor at 35°C and stir. Then add 2kg of crosslinker 4, 9kg of hydroquinone dihydroxyethyl ether, 4kg of ethylene glycol, 0.06kg of dimethyltin mercaptan, 0.8kg of N,N-bis(dimethylaminopropyl)isopropanolamine, 1kg of L1501, 0.2kg of water, 8kg of difluorochloroethane, 10kg of TCEP, 3kg of sericite, and 3kg of fumed silica. Keep the speed at 45 rpm, stir for 2h, mix well, and seal for storage.

[0082] 2) Component B: Add 15.5 kg of polyether polyol Y4 into a reactor, stir and heat to 110°C, vacuum dehydrate and degas for 2.5 hours, cool to 50°C, add 79.1 kg of pure MDI and 4.7 kg of MDI-50, heat to 85°C and keep warm for 2 hours, add 0.8 kg of PM-100 and stir for 30 minutes, take a sample and test the -NCO content, which is 28.10 wt%, cool down, discharge, and seal for storage;

[0083] Components A and B are placed in corresponding tanks of a low-pressure pouring machine, kept at 35° C., and components A and B are quickly mixed at a ratio of 100:33.1 and poured into a mold. The mold is opened after 10 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

[0084] Example 5

[0085] The preparation method of the polyether polyol X5 is:

[0086] S1: 68.8 kg of castor oil, 9.5 kg of bisphenol P, 21.6 kg of lactitol, and 2.0 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 1 hour. 605 kg of propylene oxide and 302.5 kg of heptamethylphenylcyclotetrasiloxane were slowly added dropwise at 95° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.6 kg of phosphoric acid, 35 kg of water, and 1.0 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 5 was obtained.

[0087] S2: 1010kg of intermediate polyether polyol 5 and 0.22kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 85°C after nitrogen replacement for 3 times. 1008kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X5 with a hydroxyl value of 23.3mgKOH / g, a functionality of 5.0, a number average molecular weight of 12038g / mol, and a primary hydroxyl content of 75.6%.

[0088] The preparation method of the polyether polyol Y5 is:

[0089] 99.6 kg of dipentaerythritol was used as an initiator and 2.4 kg of phosphazene salt was used as a catalyst to first catalyze the ring-opening polymerization of 2480 kg of propylene oxide and then catalyze the ring-opening polymerization of 420 kg of ethylene oxide. After sufficient reaction, unreacted polymerized monomers and small molecular substances were removed, and the catalyst was removed by acid-base neutralization to obtain polyether polyol Y5 with a hydroxyl value of 44.9 mgKOH / g, a number average molecular weight of 7497 g / mol, and a primary hydroxyl content of 76.9%.

[0090] Crosslinking agent 5 is prepared by ring-opening polymerization of trimethylolpropane and propylene oxide in a molar ratio of 1:10, with a molecular weight of 729 g / mol;

[0091] The method for preparing the polyurethane super-hydrophobic foam composite material for encapsulation comprises the following steps:

[0092] 1) Component A: weigh 90kg of polyether polyol X5 and 10kg of YB-3081 respectively and put them into a reactor at 40°C and stir. Then add 1kg of crosslinker 5, 10kg of 3-methyl-1,5-pentanediol, 0.12kg of dioctyltin dioctanoate, 1.5kg of N,N-(dimethylaminopropyl)diisopropanolamine, 0.2kg of L3003, 0.3kg of water, 10kg of ethylene dichloride, 17kg of TEP, and 4kg of glass fiber. Keep the speed at 50 rpm, stir for 2h, mix well, and seal for storage.

[0093] 2) Component B: Add 25.9 kg of polyether polyol Y5 into a reactor, stir and heat to 100°C, vacuum dehydrate and degas for 3 hours, cool to 40°C, add 68.1 kg of pure MDI and 5.2 kg of MDI-50, heat to 80°C and keep warm for 3 hours, add 0.8 kg of PM-100 and stir for 30 minutes, take a sample and test the -NCO content, which is 23.97 wt%, cool down, discharge, and seal for storage;

[0094] Components A and B are placed in corresponding tanks of a low-pressure pouring machine, kept at 25° C., and components A and B are quickly mixed at a ratio of 100:31.7 and poured into a mold. The mold is opened after 10 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

[0095] Comparative Example 1

[0096] The difference between this comparative example and Example 1 is that polyether polyol X6 is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam; the preparation method is the same as that of Example 1.

[0097] Among them, the initiator of polyether polyol X6 does not contain sorbitol, and the specific preparation method is:

[0098] S1: 115.1 kg of castor oil, 42.8 kg of bisphenol M, and 1.5 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 2 h. 600 kg of propylene oxide and 150 kg of hexaphenylcyclotrisiloxane were slowly added dropwise at 90° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.45 kg of phosphoric acid, 30 kg of water, and 0.9 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 6 was obtained.

[0099] S2: 910 kg of intermediate polyether polyol 6 and 0.20 kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 80°C after nitrogen replacement for 3 times. 1091 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X6 with a hydroxyl value of 16.5 mgKOH / g, a functionality of 2.35, a number average molecular weight of 7990 g / mol, and a primary hydroxyl content of 76.2%.

[0100] Comparative Example 2

[0101] The difference between this comparative example and Example 1 is that polyether polyol X7 is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam; the preparation method is the same as that of Example 1.

[0102] The initiator of polyether polyol X7 does not contain castor oil, and the specific preparation method is as follows:

[0103] S1: 44.9 kg bisphenol M, 21.4 kg sorbitol, and 1.5 kg phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90°C for dehydration for 2 h. 600 kg propylene oxide and 150 kg hexaphenylcyclotrisiloxane were slowly added dropwise at 90°C. The pressure was controlled to be less than 0.30 MPa during the reaction. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85°C, and 0.45 kg phosphoric acid, 30 kg water, and 0.9 kg magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 7 was obtained.

[0104] S2: 818 kg of intermediate polyether polyol 7 and 0.20 kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 80°C after nitrogen replacement for 3 times. 1182 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X7 with a hydroxyl value of 27.5 mgKOH / g, a functionality of 3.9, a number average molecular weight of 7956 g / mol, and a primary hydroxyl content of 76.6%.

[0105] Comparative Example 3

[0106] The difference between this comparative example and Example 1 is that polyether polyol X8 is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam; the preparation method is the same as that of Example 1.

[0107] Among them, the initiator of polyether polyol X8 does not contain bisphenol M, and the specific preparation method is:

[0108] S1: 146.6 kg of castor oil, 21.4 kg of sorbitol, and 1.5 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 2 h. 600 kg of propylene oxide and 150 kg of hexaphenylcyclotrisiloxane were slowly added dropwise at 90° C. The pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., and 0.45 kg of phosphoric acid, 30 kg of water, and 0.9 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 8 was obtained.

[0109] S2: 920 kg of intermediate polyether polyol 8 and 0.20 kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 80°C after nitrogen replacement for 3 times. 1080 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X8 with a hydroxyl value of 27.1 mgKOH / g, a functionality of 3.9, a number average molecular weight of 8073 g / mol, and a primary hydroxyl content of 75.9%.

[0110] Comparative Example 4

[0111] The difference between this comparative example and Example 1 is that polyether polyol X9 is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam; the preparation method is the same as that of Example 1.

[0112] Among them, the initiator of polyether polyol X9 does not contain hexaphenylcyclotrisiloxane, and the specific preparation method is:

[0113] S1: 115.1 kg of castor oil, 9.6 kg of bisphenol M, 17.4 kg of sorbitol, and 1.5 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 2 h. 752 kg of propylene oxide was slowly added dropwise at 90° C. The pressure was controlled to be less than 0.30 MPa during the reaction. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. The unreacted residual monomers were removed by vacuumization. The temperature was lowered to 85° C., 0.45 kg of phosphoric acid, 30 kg of water, and 0.9 kg of magnesium silicate were added in sequence. After dehydration and filtration, the intermediate polyether polyol 9 was obtained.

[0114] S2: 894 kg of intermediate polyether polyol 9 and 0.20 kg of tri(pentafluorophenyl)borane were added to a pressure reactor. The temperature was raised to 80°C after nitrogen replacement for 3 times. 1107 kg of propylene oxide was continuously added dropwise. The pressure was controlled to be less than 0.30 MPa during the reaction. The internal pressure was reacted until the pressure no longer decreased. The unreacted residual monomers were removed by vacuum to obtain the target polyether polyol X9 with a hydroxyl value of 27.5 mgKOH / g, a functionality of 3.9, a number average molecular weight of 7956 g / mol, and a primary hydroxyl content of 76.7%.

[0115] Comparative Example 5

[0116] The difference between this comparative example and Example 1 is that polyether polyol X10 is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam; the preparation method is the same as that of Example 1.

[0117] Among them, the initiator of polyether polyol X10 contains ethylene oxide, and the specific preparation method is as follows:

[0118] 115.1kg castor oil, 9.6kg bisphenol M, 17.4kg sorbitol and 1.5kg phosphazene catalyst were added to the pressure reactor. After nitrogen replacement for 3 times, the temperature was raised to 90℃ for dehydration for 2h. 1308kg propylene oxide and 150kg hexaphenylcyclotrisiloxane were slowly added dropwise at 90℃. The pressure was controlled to be less than 0.30MPa during the reaction. After the reaction was completed, the internal pressure reaction was continued until the pressure no longer decreased. Then 1308kg ethylene oxide was slowly added dropwise. , control the pressure during the reaction to be less than 0.30MPa, continue the internal pressure reaction after the reaction is completed until the pressure no longer decreases, evacuate to remove the unreacted residual monomers, cool to 85°C, add 0.45kg of phosphoric acid, 70kg of water, and 2kg of magnesium silicate in sequence, dehydrate and filter to obtain the target polyether polyol X10, with a hydroxyl value of 28.0mgKOH / g, a functionality of 3.9, a number average molecular weight of 7814g / mol, and a primary hydroxyl content of 74.8%.

[0119] Comparative Example 6

[0120] The difference between this comparative example and Example 1 is that polyether polyol INOVOL F330N is used instead of polyether polyol X1 to prepare polyurethane super hydrophobic foam. The preparation method is the same as that of Example 1.

[0121] Comparative Example 7

[0122] The difference between this comparative example and Example 1 is that DG5411 is used instead of component B to prepare polyurethane super hydrophobic foam, and the preparation method is the same as Example 1.

[0123] The polyurethane super-hydrophobic foams prepared in Examples 1 to 5 and Comparative Examples 1 to 7 were placed in an environment at 25°C for 72 hours and then subjected to performance tests, wherein the core density was tested in accordance with GB / T 6343-2009, the hardness was tested in accordance with GB / T 10807-2006, the tensile strength and elongation at break were tested in accordance with GB / T 6344-2008, and the wet heat aging resistance was tested in accordance with the requirements of GB / T9640-2008. The foams were treated at a temperature of 120°C and a humidity of 100% for 72 hours, and the loss rates of tensile strength and elongation at break were calculated. The static water contact angle of the foam surface after aging was measured using a contact angle meter. The test results are shown in Table 1:

[0124] Table 1 Test results of polyurethane super hydrophobic foam performance of Examples 1 to 5 and Comparative Examples 1 to 7

[0125]

[0126] It can be seen from the data in Table 1 that the polyurethane super-hydrophobic foam prepared by the embodiment of the present invention has a static water contact angle of more than 150°, which is significantly better than the comparative example, indicating that it has excellent hydrophobic properties; after being treated for 72 hours in a hot and humid environment at a temperature of 120°C and a humidity of 100%, the mechanical property loss rate does not exceed 5%, which is significantly better than the comparative example, and its high temperature resistance and hydrolysis resistance are greatly improved.

Claims

1. A polyurethane super-hydrophobic foam composition for encapsulation, characterized in that: Prepared by reacting component A and component B at a mass ratio of 100: (31.7~46.5); Wherein, the component A is composed of the following raw materials in parts by weight: polyether polyol X: 70-95 parts, polymer polyol: 5-30 parts, chain extender: 10-20 parts, cross-linking agent: 1-3 parts, organic metal catalyst: 0.04-0.12 parts, tertiary amine catalyst: 0.5-1.5 parts, foam stabilizer: 0.2-1.0 parts, foaming agent: 8.2-20.1 parts, flame retardant: 10-20 parts, inorganic filler: 2-10 parts; The component B is an isocyanate modified by polyether polyol Y, with an isocyanate content of 24-28%, and is composed of the following raw materials in parts by weight: polyether polyol Y: 15.5-25.9 parts, pure MDI: 68.1-79.1 parts; MDI-50: 4.7-6.9 parts, polymethylene polyphenyl polyisocyanate: 0.5-0.8 parts; The polyether polyol X in the component A is a high molecular weight and high activity polyether polyol with an average functionality of 2.7 to 5.0; the organic metal catalyst in the component A is a tin catalyst; the tertiary amine catalyst in the component A is one of N-methyldicyclohexylamine, pentamethyldiethylenetriamine, N,N-bis(dimethylaminopropyl)isopropanolamine and N,N-(dimethylaminopropyl)diisopropanolamine; The high molecular weight and high activity polyether polyol in the component A has a number average molecular weight of 4000-12000 g / mol, a primary hydroxyl content of ≥70%, and an ester bond, a rigid benzene ring group, and a Si-O-Si segment in the polyether segment. The polyether polyol is prepared by ring-opening polymerization of castor oil, a benzene ring-containing initiator, and an initiator with a functionality of 4 or more as a composite initiator, in the presence of a phosphazene catalyst and a Lewis acid catalyst, with propylene oxide and cyclosiloxane in a mass ratio of (5.3-17.2):1; The benzene ring-containing initiator of the polyether polyol X is one or a mixture of two of bisphenol A, bisphenol fluorene, tetrabromobisphenol A, tetrachlorobisphenol A, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene; the initiator with a functionality of 4 or more is one or a mixture of two of pentaerythritol, erythritol, xylitol, sorbitol, mannitol, and lactitol; The cyclosiloxane is a phenyl-containing cyclosiloxane, and the amount used is 2-20% of the total mass of the raw materials in the reaction system; The Lewis acid catalyst is an alkyl borane or a borate; the mass ratio of castor oil, an initiator containing a benzene ring and an initiator with a functionality of 4 or more is (3.68-12):1:(0.2-2.28).

2. The polyurethane super-hydrophobic foam composition for encapsulation according to claim 1, characterized in that: The crosslinking agent in the component A is prepared by ring-opening polymerization of propylene oxide and / or ethylene oxide with a small molecule alcohol or a small molecule amine having trifunctional or higher functions as an initiator, and the molar ratio of the initiator to the alkylene oxide is 1: (1-30).

3. The polyurethane super-hydrophobic foam composition for encapsulation according to claim 1, characterized in that: The chain extender in component A is an alcohol chain extender, the polymer polyol is a flame retardant polymer polyol, the flame retardant is one of TCPP, TCEP, DMMP and TEP; the foam stabilizer is one of DC193, DC3042, DC3043, L1501 and L3003 or a mixture of two thereof.

4. The encapsulation polyurethane super-hydrophobic foam composition according to claim 1, characterized in that: The foaming agent in the component A comprises a mixture of a physical foaming agent and a chemical foaming agent, the mass ratio of the physical foaming agent to the chemical foaming agent is (40-200):1, the physical foaming agent is one of difluoromonochloroethane, dichloroethane, and butane, and the chemical foaming agent is water.

5. The polyurethane super-hydrophobic foam composition for encapsulation according to claim 1, characterized in that: The inorganic filler in the component A is one or two of fumed silica, sericite, calcium sulfate and glass fiber.

6. A method for preparing the polyurethane super-hydrophobic foam composition for encapsulation according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) Preparation of component A: Add polyether polyol X and polymer polyol into a reaction kettle at 30-40°C and stir, then add chain extender, cross-linking agent, organic metal catalyst, tertiary amine catalyst, foam stabilizer, foaming agent, flame retardant, inorganic filler, rotate at 40-50 rpm, stir for 1-2 hours, and seal for storage; 2) Preparation of component B: put polyether polyol Y into a reactor, stir and heat to 100-110°C, vacuum dehydrate and degas for 2-3 hours, cool to 40-50°C, add pure MDI and MDI-50, heat to 80-85°C and keep warm for 2-3 hours, add polymethylene polyphenyl isocyanate and stir for 30 minutes, take samples to test the -NCO content to be between 24-28wt%, cool down, discharge, and seal for storage; 3) Place components A and B in corresponding tanks of a low-pressure pouring machine, keep the temperature at 25-35°C, mix components A and B in proportion and pour them into a mold. Open the mold after 10-20 minutes to obtain the polyurethane super-hydrophobic foam composite material for encapsulation.

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