Polyurethane-based spraying material and application of polyurethane-based spraying material and ethylene-propylene-diene monomer composite thermal insulation layer

Abstract

The invention relates to the technical field of heat insulation materials, and particularly discloses a polyurethane-based spraying material and application of the polyurethane-based spraying material and an ethylene-propylene-diene monomer composite heat insulation layer, the polyurethane-based spraying material comprises a component A and a component B. The component A comprises, by mass, 50-70% of isocyanate prepolymer, 10-20% of liquid rubber, 10-20% of ablation-resistant resin, 5-10% of fiber filler and 1-5% of plasticizer. And the component B comprises 45%-70% of amino-terminated polyether, 1%-3% of a vulcanization cross-linking agent, 2%-6% of a vulcanization activation accelerator, 5%-15% of a chain extender, 10%-15% of fiber filler, 10%-15% of ablation-resistant resin and 1%-5% of a plasticizer. The liquid rubber curing system is introduced into the spraying heat-insulating material, so that the bonding strength of the polyurethane-based spraying heat-insulating material and the EPDM heat-insulating material is improved, a polyurethane / EPDM rubber composite heat-insulating layer can be manufactured, and a new solution is provided for production and manufacturing of the engine spraying heat-insulating layer.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation and ablation-resistant materials for solid rocket engines, and in particular to a polyurethane-based spray material and an application of the polyurethane-based spray material and an EPDM composite thermal insulation layer. Background Art

[0002] Solid rocket engines use insulation layers for heat insulation and ablation protection. Currently, commonly used ablative insulation materials are nitrile, EPDM and silicone rubber insulation materials. This type of rubber insulation is made using patch or molding processes, and has problems such as low production efficiency and low product quality stability.

[0003] CN115028987 A discloses a sprayable polyurethane ablation-resistant material formula, preparation method and application, which can prepare thermal insulation materials through spray molding to improve work efficiency. The molecular polarity of the spray polyurethane material is relatively high, and the bonding performance with the nitrile thermal insulation material is good, but the molecular polarity of the spray polyurethane material is quite different from that of the EPDM thermal insulation material, and the bonding strength is relatively low. The usual method to solve the interface bonding is to use an adhesive to bond the interface, but the EPDM rubber is vulcanized at a high temperature of 150℃-160℃, and the spray thermal insulation material is cured at room temperature or medium temperature (50℃~90℃). The curing temperatures used by the two thermal insulation materials are quite different, and the curing temperature of the adhesive is difficult to simultaneously meet the curing temperature range of the two thermal insulation materials. Summary of the invention

[0004] The invention provides a polyurethane-based spraying material and an application of the same with an EPDM composite thermal insulation layer, and introduces a liquid rubber curing system into the spraying thermal insulation material, thereby solving the problem of poor bonding quality between the polyurethane-based spraying thermal insulation material and the EPDM rubber thermal insulation material.

[0005] The technical solution of the present invention is to provide a polyurethane-based spray material, comprising component A and component B, wherein component A comprises, by mass fraction, 50% to 70% isocyanate prepolymer, 10% to 20% liquid rubber, 10% to 20% ablation-resistant resin, 5% to 10% fiber filler and 1% to 5% plasticizer.

[0006] Component B: 45%~70% amino-terminated polyether, 1%~3% vulcanization crosslinking agent, 2%~6% vulcanization activation accelerator, 5%~15% chain extender, 10%~15% fiber filler, 10%~15% ablation-resistant resin and 1%~5% plasticizer.

[0007] Optionally, the isocyanate prepolymer is one or more of hexamethylene diisocyanate (HDI) or diphenylmethane-4,4-diisocyanate (MDI).

[0008] Optionally, the liquid rubber is one or more of maleic anhydride grafted liquid isoprene rubber, maleic anhydride grafted liquid EPDM rubber and maleic anhydride grafted liquid polybutadiene.

[0009] Optionally, when maleic anhydride is grafted onto liquid rubber, maleic anhydride (MAH) is used as a grafting agent, an anionic initiator or a peroxide initiator is used, and a solution grafting method is used for grafting. The ratio of maleic anhydride to liquid rubber in the preparation of maleic anhydride grafted liquid rubber is 100: (2-6), diisopropylbenzene peroxide is used as an initiator, the reaction temperature is 120 min ~ 160 ° C, and the reaction time is 30 min ~ 120 min.

[0010] Optionally, component A and component B satisfy at least one of the following conditions: the ablation-resistant resin is one or both of polyimide resin and phenolic resin; the fiber filler is one or both of carbon fiber and basalt fiber; and the plasticizer is dioctyl phthalate.

[0011] Optionally, the amino-terminated polyether is one or both of CGA-D2000 and CGA-T5000.

[0012] Optionally, the B component satisfies at least one of the following conditions: the vulcanization crosslinking agent is one or more of diisopropylbenzene peroxide, di-tert-butyl diisopropylbenzene peroxide or dimethyl di-tert-butyl peroxide; the vulcanization activation accelerator is one or more of zinc oxide, stearic acid, zinc stearate, N,N-dicyclohexyl-2-benzothiazole sulfonamide (CZ), N-tert-butyl-2-benzothiazole sulfonamide (NS), tetrapentamethylenethiuram tetrasulfide (TRA) and zinc dimethyldithiocarbamate (PZ); the chain extender is one or more of 3,3-dichloro-4,4-diaminodiphenylmethane (MOCA), diethyltoluenediamine (DETDA) and N,N-dialkylphenylenediamine.

[0013] The invention also relates to a method for preparing the polyurethane-based spray material, wherein component A and component B are prepared respectively according to a ratio, and before use, component A and component B are mixed evenly and placed in a spraying device for spraying.

[0014] The invention also relates to the application of the polyurethane-based spray material in the preparation of a thermal insulation layer of a solid rocket engine.

[0015] Optionally, the thermal insulation layer is a polyurethane / ethylene propylene diene monomer rubber composite thermal insulation layer.

[0016] The present invention has the following beneficial effects: 1. Liquid rubber is added to the polyurethane-based spray material provided by the present invention, wherein the liquid rubber is grafted with maleic anhydride polar functional groups to increase a part of the polarity of the liquid rubber, so that it has a certain compatibility with the polyurethane-based resin, increases the "interface affinity", and makes the mixing and dispersion more uniform. At the same time, the long-chain structure of the liquid rubber has similar properties to EPDM rubber. The addition of the liquid rubber to the polyurethane-based spray material improves the interfacial bonding performance between the spray material and the EPDM rubber, which can effectively solve the problem of poor bonding quality between the polyurethane-based spray insulation material and the EPDM rubber insulation material.

[0017] 2. A rubber peroxide vulcanization system is also introduced into the polyurethane-based spray material of the present invention, forming a "dual-curing" network system with the spray polyurethane system, so that when the material is bonded with the EPDM insulation material, a co-"vulcanization bond" is formed at the interface, thereby improving the interfacial bonding performance between the polyurethane-based spray insulation material and the EPDM insulation layer. DETAILED DESCRIPTION

[0018] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified.

[0019] The polyurethane-based spray material provided by the present invention comprises component A and component B, wherein component A comprises 50% to 70% of isocyanate prepolymer, 10% to 20% of liquid rubber, 10% to 20% of ablation-resistant resin, 5% to 10% of fiber filler and 1% to 5% of plasticizer, and component B comprises 45% to 70% of amino-terminated polyether, 1% to 3% of vulcanization crosslinking agent, 2% to 6% of vulcanization activation accelerator, 5% to 15% of chain extender, 10% to 15% of fiber filler, 10% to 15% of ablation-resistant resin and 1% to 5% of plasticizer, according to mass fraction.

[0020] In some embodiments, the isocyanate prepolymer is one or more of hexamethylene diisocyanate (HDI) or diphenylmethane-4,4-diisocyanate (MDI).

[0021] In some embodiments, the ablation-resistant resin is one or both of a polyimide resin and a phenolic resin.

[0022] In some embodiments, the fiber filler is one or both of carbon fiber and basalt fiber.

[0023] In some embodiments, the plasticizer is dioctyl phthalate.

[0024] In some embodiments, the amino-terminated polyether is one or both of CGA-D2000 and CGA-T5000.

[0025] In some embodiments, the vulcanization crosslinking agent is one or more of diisopropylbenzene peroxide, di-tert-butyl diisopropylbenzene peroxide, or dimethyl di-tert-butyl peroxide.

[0026] In some embodiments, the vulcanization activation accelerator is one or more of zinc oxide, stearic acid, zinc stearate, N,N-dicyclohexyl-2-benzothiazole sulfenamide (CZ), N-tert-butyl-2-benzothiazole sulfenamide (NS), dipentamethylenethiuram tetrasulfide (TRA), and zinc dimethyldithiocarbamate (PZ).

[0027] In some embodiments, the chain extender is one or more of 3,3-dichloro-4,4-diaminodiphenylmethane (MOCA), diethyltoluenediamine (DETDA), and N,N-dialkylphenylenediamine.

[0028] The liquid rubber in the present invention is one or more of maleic anhydride grafted liquid isoprene rubber, maleic anhydride grafted liquid EPDM rubber and maleic anhydride grafted liquid polybutadiene.

[0029] In a preferred embodiment, the maleic anhydride grafted liquid rubber is prepared by grafting maleic anhydride (MAH) with an anionic initiator or a peroxide initiator using a solution grafting method. The weight ratio of maleic anhydride to liquid rubber in the preparation of the maleic anhydride grafted liquid rubber is (2-5):100, diisopropylbenzene peroxide is used as an initiator in an amount of 1-2.5 parts, the reaction temperature is 130°C-150°C, and the reaction time is 30 min-120 min.

[0030] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0031] Example 1 The formula of the polyurethane-based spray material is shown in Table 1.

[0032] Table 1

[0033] When preparing the liquid rubber maleic anhydride grafted product, the feed ratio of liquid EPDM rubber to maleic anhydride is 100:5, the amount of initiator diisopropylbenzene peroxide is 2.5 parts, the reaction temperature is 150° C., and the reaction time is 120 min.

[0034] When preparing the polyurethane-based spray material, first prepare component A and component B according to the ratio, mix component A and component B before use, place them in the spray equipment, and spray. The mass ratio of component A to component B is 1.02:1.

[0035] Example 2 The formula of polyurethane-based spray material is shown in Table 2.

[0036] Table 2

[0037] When preparing the liquid rubber maleic anhydride grafted product, the feed ratio of liquid isoprene rubber to maleic anhydride is 100:2, the amount of initiator diisopropylbenzene peroxide is 1 part, the reaction temperature is 130° C., and the reaction time is 30 min.

[0038] The preparation of the polyurethane-based spray material is the same as in Example 1.

[0039] Example 3 The formula of polyurethane-based spray material is shown in Table 3.

[0040] Table 3

[0041] When preparing the liquid rubber maleic anhydride grafted product, the feed ratio of liquid polybutadiene rubber to maleic anhydride is 100:3, the amount of initiator diisopropylbenzene peroxide is 1.5 parts, the reaction temperature is 130° C., and the reaction time is 60 minutes.

[0042] The preparation of the polyurethane-based spray material is the same as in Example 1.

[0043] Example 4 The formula of polyurethane-based spray material is shown in Table 4.

[0044] Table 4

[0045] The specific preparation method of the liquid rubber maleic anhydride grafted material and the preparation of the polyurethane-based spray material are the same as those in Example 1.

[0046] Comparative Example 1: Taking Example 1 as the object, the mass of maleic anhydride grafted liquid ethylene propylene rubber in component A is replaced by hexamethylene diisocyanate, and the diisopropylbenzene peroxide, zinc oxide, stearic acid and N-tert-butyl-2-benzothiazolesulfonamide in component B are replaced by CGA-D2000 in the same proportion, and the other components and proportions remain unchanged. The polyurethane spray material is prepared in the same way as in Example 1.

[0047] Comparative Example 2 Based on Example 1, the only difference is that the mass of maleic anhydride grafted liquid EPDM rubber is replaced by liquid EPDM rubber (ie, no maleic anhydride grafting modification is performed).

[0048] Comparative Example 3 Based on Example 1, diisopropylbenzene peroxide, zinc oxide, stearic acid and N-tert-butyl-2-benzothiazolesulfonamide in component B were replaced with CGA-D2000 in the same proportion, and the other components and proportions remained unchanged, and a polyurethane spray material was prepared in the same manner as in Example 1.

[0049] The polyurethane spray materials obtained in the above embodiments and comparative examples were sampled and tested with reference to relevant test standards. The oxygen-acetylene line ablation rate test was based on GJB 323A, the tear strength test was based on aerospace industry standard QJ 2038.1, and the peel strength test was based on GB / T 2791. The specific performance of the test results is shown in Table 5.

[0050] Table 5

[0051] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polyurethane-based spray material, characterized in that: It comprises component A and component B. According to the mass fraction, component A comprises 50% to 70% of isocyanate prepolymer, 10% to 20% of liquid rubber, 10% to 20% of ablation-resistant resin, 5% to 10% of fiber filler and 1% to 5% of plasticizer. Component B: 45%~70% amino-terminated polyether, 1%~3% vulcanization crosslinking agent, 2%~6% vulcanization activation accelerator, 5%~15% chain extender, 10%~15% fiber filler, 10%~15% ablation-resistant resin and 1%~5% plasticizer.

2. The polyurethane-based spray material according to claim 1, characterized in that: The isocyanate prepolymer is one or more of hexamethylene diisocyanate (HDI) and diphenylmethane-4,4-diisocyanate (MDI).

3. The polyurethane-based spray material according to claim 1, characterized in that: The liquid rubber is one or more of maleic anhydride grafted liquid isoprene rubber, maleic anhydride grafted liquid EPDM rubber and maleic anhydride grafted liquid polybutadiene.

4. The polyurethane-based spray material according to claim 3, characterized in that: When maleic anhydride is grafted onto liquid rubber, maleic anhydride (MAH) is used as a grafting agent, an anionic initiator or a peroxide initiator is used, and a solution grafting method is used for grafting.

5. The polyurethane-based spray material according to claim 1, characterized in that: Component A and component B meet at least one of the following conditions: the ablation-resistant resin is one or both of polyimide resin and phenolic resin; the fiber filler is one or both of carbon fiber and basalt fiber; and the plasticizer is dioctyl phthalate.

6. The polyurethane-based spray material according to claim 1, characterized in that: The amino-terminated polyether is one or both of CGA-D2000 and CGA-T5000.

7. The polyurethane-based spray material according to claim 1, characterized in that: The B component satisfies at least one of the following conditions: the vulcanization crosslinking agent is one or more of diisopropylbenzene peroxide, di-tert-butyl diisopropylbenzene peroxide or dimethyl di-tert-butyl peroxide; the vulcanization activation accelerator is one or more of zinc oxide, stearic acid, zinc stearate, N,N-dicyclohexyl-2-benzothiazole sulfenamide (CZ), N-tert-butyl-2-benzothiazole sulfenamide (NS), tetrapentamethylenethiuram tetrasulfide (TRA) and zinc dimethyldithiocarbamate (PZ); the chain extender is one or more of 3,3-dichloro-4,4-diaminodiphenylmethane (MOCA), diethyltoluenediamine (DETDA) and N,N-dialkylphenylenediamine.

8. The method for preparing the polyurethane-based spray material according to any one of claims 1 to 7, characterized in that: Prepare component A and component B respectively according to the ratio, mix component A and component B evenly before use, place them in the spraying equipment, and spray them.

9. Use of the polyurethane-based spray material according to any one of claims 1 to 7 in the preparation of thermal insulation layers of solid rocket engines.

10. The use according to claim 9, characterized in that: The heat insulating layer is a polyurethane / ethylene propylene diene monomer rubber composite heat insulating layer.

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