Polyphosphazene modified polyurethane-based spraying thermal insulation material and preparation method thereof

Abstract

The invention relates to the technical field of thermal insulation materials, and particularly discloses a polyphosphazene modified polyurethane-based spraying thermal insulation material and a preparation method thereof.The thermal insulation material comprises a component A and a component B. The component A comprises, by mass, 60%-70% of isocyanate prepolymer, 10%-20% of ablation-resistant resin, 5%-15% of fiber filler and 5%-15% of viscosity reducer; the component B comprises 30%-40% of amine-terminated polyether, 20%-40% of modified polyphosphazene, 8%-15% of a chain extender, 10%-20% of fiber filler, 5%-15% of ablation-resistant resin and 5%-15% of a viscosity reducer. The modified polyphosphazene containing hydroxyl and amino is added, N-P groups with strong polarity are introduced, the polarity of the polyurethane-based spraying thermal insulation material is improved, the bonding strength of the spraying thermal insulation material and composite materials such as rubber, steel and carbon fibers can be improved, an adhesive bonding interface is not needed, and solvent-free, green and safe manufacturing of the engine thermal insulation layer is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal protection materials for solid rocket engines, and in particular to a polyphosphazene-modified polyurethane-based spray insulation material and a preparation method thereof. Background Art

[0002] The main function of the solid engine insulation layer is to prevent high-temperature, high-pressure propellant gas from damaging the engine casing and causing the engine to fail. At present, nitrile and EPDM rubber insulation sheets are generally pasted to the inner wall of the engine casing. This patch process has problems such as many manual operations, low production efficiency and poor molding quality consistency, which seriously restricts the high-quality, high-efficiency and low-cost production of weapons and equipment engines.

[0003] CN115028987 A discloses a sprayable polyurethane ablation-resistant material formula, preparation method and application, which can be used to prepare thermal insulation materials by spray molding. However, the oxygen-acetylene line ablation rate of the polyurethane-based spray thermal insulation material provided by the formula is 0.11~0.21mm / s. The ablation performance of the formula can only meet the requirements of engines with less harsh working ablation environments, and there is a certain gap in the ablation performance compared with traditional nitrile and EPDM rubber thermal insulation materials.

[0004] In CN117186618A, the oxygen-acetylene line ablation rate of the insulation material can be reduced to below 0.1 mm / by adding an anti-scour reinforcement layer and compounding it with the spray material. However, the fiber-reinforced polyurethane-based spray insulation material has poor flexibility and is only suitable for the anti-scour and ablation area of ​​the engine, and cannot meet the insulation structure requirements of the engine barrel section. Summary of the invention The present invention provides a polyphosphazene-modified polyurethane-based spray insulation material and a preparation method thereof. The material has good anti-ablation performance and good mechanical flexibility, and can meet the application requirements of the spray insulation material in different scenarios and fields.

[0005] The technical solution of the present invention is to provide a polyphosphazene modified polyurethane-based spray insulation material, characterized in that it comprises component A and component B, wherein component A comprises 60% to 70% of isocyanate prepolymer, 10% to 20% of ablation-resistant resin, 5% to 15% of fiber filler and 5% to 15% of viscosity reducer, and component B comprises 30% to 40% of terminal amino polyether, 20% to 40% of modified polyphosphazene, 8% to 15% of chain extender, 10% to 20% of fiber filler, 5% to 15% of ablation-resistant resin and 5% to 15% of viscosity reducer, calculated by mass fraction.

[0006] Optionally, the isocyanate prepolymer is one or more of hexamethylene diisocyanate (HDI), diphenylmethane-4,4-diisocyanate (MDI), isophorone diisocyanate (IPDI) and xylylene diisocyanate (XDI).

[0007] Optionally, 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, aramid fiber and basalt fiber; the viscosity reducer is one or both of octyl phthalate and tri(2-ethylhexyl) phosphate; Optionally, the amino-terminated polyether is one or more of CGA-T403, CGA-D2000 and CGA-T5000.

[0008] Optionally, the modified polyphosphazene is a polyphosphazene containing hydroxyl groups and amino groups.

[0009] Optionally, the modified polyphosphazene preparation method comprises the following steps: The hexachlorocyclotriphosphazene is dissolved in a solvent, an ethylenediamine solution is added dropwise to react, glycerol is then added dropwise and the temperature is raised to react, and finally precipitation is carried out in methanol, and the precipitate is filtered and washed to obtain the modified polyphosphazene.

[0010] Optionally, the preparation of the modified polyphosphazene satisfies at least one of the following conditions: the solvent is anhydrous tetrahydrofuran or dichloromethane; the molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol is 1:0.5-1:0.3-1.5; the reaction temperature after dropwise addition of ethylenediamine solution is 0-5°C; the temperature of the heating reaction after dropwise addition of glycerol is 40-60°C; and the total reaction time of the modified polyphosphazene is 6-12h.

[0011] Optionally, the chain extender is one or more of diethyltoluenediamine, dimethylthiotoluenediamine and N,N-dialkylmethyldiamine.

[0012] The present invention also relates to a method for preparing the thermal insulation material, comprising the following steps: S1. Mix the raw materials of component A evenly under a protective atmosphere, and mix the raw materials of component B evenly; S2. Component A and component B are mixed, and then sprayed, and then cured to obtain a thermal insulation material.

[0013] Optionally, during curing, the sample is first cured at room temperature for 24 to 48 hours, then cured at 70 to 90° C. for 48 hours, and finally cured at 110 to 130° C. for 24 to 72 hours.

[0014] The present invention has the following beneficial effects: Polyphosphazene has excellent carbon-forming and high-temperature resistance. The present invention copolymerizes the polyphosphazene material with a polyurethane resin by chemical bonding to form a polyphosphazene-polyurethane composite resin material, thereby improving the anti-ablation performance of the matrix resin, thereby improving the anti-ablation performance of the polyurethane-based spray insulation material, so that it has both good mechanical flexibility and ablation resistance.

[0015] The polyphosphazene added in the present invention is a modified polyphosphazene containing hydroxyl and amino groups, which introduces a strong polar NP group, increases the polarity of the polyurethane-based spray insulation material, and can improve the bonding strength between the spray insulation material and composite materials such as rubber, steel and carbon fiber, without the need for an adhesive bonding interface, thereby achieving solvent-free green and safe manufacturing of the engine insulation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The polyphosphazene-modified polyurethane-based spray insulation material sample prepared in Example 1 is a schematic diagram of the sample before and after ablation. DETAILED DESCRIPTION

[0017] 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.

[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 spray insulation material formula contains the following raw materials in terms of mass fraction: Component A: 60%~70% isocyanate prepolymer, 10%~20% ablation-resistant resin, 5%~15% fiber filler and 5%~15% viscosity reducer.

[0020] Component B: 30%~40% amino-terminated polyether, 20%~40% modified polyphosphazene, 8%~15% chain extender, 10%~20% fiber filler, 5%~15% ablation-resistant resin, and 5%~15% viscosity reducer.

[0021] The isocyanate prepolymer includes one or more of hexamethylene diisocyanate (HDI), diphenylmethane-4,4-diisocyanate (MDI), isophorone diisocyanate (IPDI) and xylene diisocyanate (XDI). The ablation-resistant resin is one or both of polyimide resin and phenolic resin. The fiber filler is one or more of carbon fiber, aramid fiber and basalt fiber. The viscosity reducer is one or both of octyl phthalate and tri(2-ethylhexyl) phosphate. The amino-terminated polyether is one or more of CGA-T403, CGA-D2000 and CGA-T5000. The chain extender is one or more of diethyltoluenediamine, dimethylthiotoluenediamine and N,N-dialkylmethyldiamine.

[0022] The modified polyphosphazene is a polyphosphazene containing hydroxyl groups and amino groups, and its preparation method comprises the following steps: S1: Dissolve hexachlorocyclotriphosphazene in an appropriate amount of anhydrous tetrahydrofuran or dichloromethane, add an appropriate amount of ethylenediamine solution to the solution, maintain the temperature at 0-5°C, and keep the reaction for 30 minutes after the addition is completed.

[0023] S2: After the amine reaction is completed, slowly add a certain amount of glycerol liquid, keep the temperature at 20-25°C during the addition, and raise the temperature to 40-60°C after the addition is completed, and continue to stir the reaction.

[0024] S3: After the reaction is completed, the reaction mixture is poured into a large amount of cold methanol for precipitation, and the precipitated polyphosphazene product is collected. The precipitate is washed with ethanol several times to remove unreacted raw materials and by-products. The polyphosphazene product is dried in a vacuum dryer for 24 hours at a temperature of 40-60°C. After drying, it is set aside.

[0025] Embodiment 1: A polyphosphazene-modified polyurethane-based spray insulation material formula and preparation method, wherein the formula and related properties are shown in Table 1.

[0026] Table 1

[0027] In this embodiment, the molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol in the modified polyphosphazene synthesis process is 1:0.7:0.8, and the reaction time is 6 hours (the reaction time after adding ethylenediamine is 2 hours, and the reaction time after adding glycerol is 4 hours).

[0028] Preparation of polyphosphazene modified polyurethane based spray insulation material: The raw materials of component A are mixed evenly under a protective atmosphere, and the raw materials of component B are mixed evenly; then component A and component B are mixed at a mass ratio of 1.02 to 1, and spraying operation is carried out. The obtained sample is first cured at room temperature for 24 hours, then cured at 70°C for 48 hours, and finally cured at 110°C for 48 hours to obtain the insulation material.

[0029] from Figure 1 It can be seen that the polyphosphazene-modified polyurethane-based spray insulation material prepared in this embodiment has good ablation resistance.

[0030] Embodiment 2: A formula and preparation method of a polyphosphazene-modified polyurethane-based spray insulation material, wherein the formula and related properties are shown in Table 2.

[0031] Table 2

[0032] The molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol in the modified polyphosphazene synthesis process is 1:0.9:1.0, and the total reaction time is controlled to be 10 hours.

[0033] Preparation of polyphosphazene modified polyurethane based spray insulation material: The raw materials of component A are mixed evenly under a protective atmosphere, and the raw materials of component B are mixed evenly; then component A and component B are mixed at a mass ratio of 1.02 to 1, and spraying operation is carried out. The obtained sample is first cured at room temperature for 48 hours, then cured at 70°C for 48 hours, and finally cured at 120°C for 24 hours to obtain the insulation material.

[0034] Embodiment 3: A formula and preparation method of a polyphosphazene-modified polyurethane-based spray insulation material, wherein the formula and related properties are shown in Table 3.

[0035] Table 3

[0036] The molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol in the modified polyphosphazene synthesis process is 1:0.5:0.5, and the total reaction time is 6 hours.

[0037] In the preparation of polyphosphazene modified polyurethane-based spray insulation material, the raw materials of component A are mixed evenly under a protective atmosphere, and the raw materials of component B are mixed evenly; then component A and component B are mixed at a mass ratio of 1.02 to 1, and spraying operation is carried out. The obtained sample is first cured at room temperature for 48 hours, then cured at 90°C for 48 hours, and finally cured at 130°C for 48 hours to obtain the insulation material.

[0038] Embodiment 4: A formula and preparation method of a polyphosphazene-modified polyurethane-based spray insulation material, wherein the formula and related properties are shown in Table 4.

[0039] Table 4

[0040] The molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol in the modified polyphosphazene synthesis process is 1:1.0:1.4, and the total reaction time is 12h.

[0041] Preparation of polyphosphazene modified polyurethane based spray insulation material: The raw materials of component A are mixed evenly under a protective atmosphere, and the raw materials of component B are mixed evenly; then component A and component B are mixed at a mass ratio of 1.02:1 and sprayed. The obtained sample is first cured at room temperature for 48 hours, then cured at 80°C for 48 hours, and finally cured at 120°C for 72 hours to obtain the insulation material.

[0042] Comparative Example 1 Based on the formulation of Example 1, the modified polyphosphazene was replaced by CGA-D2000, the other components of the formulation remained unchanged, and the preparation process parameters were the same as those of Example 1. The properties of the obtained samples are shown in Table 5.

[0043] Table 5

[0044] Comparative Example 2 Based on the formulation of Example 1, the modified polyphosphazene was replaced by commercially available phenoxy polyphosphazene, the other components of the formulation remained unchanged, and the preparation process parameters were the same as those of Example 1. The properties of the obtained samples are shown in Table 6.

[0045] Table 6

[0046] 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 polyphosphazene modified polyurethane-based spray insulation material, characterized in that: The invention comprises component A and component B. Component A comprises 60% to 70% of isocyanate prepolymer, 10% to 20% of ablation-resistant resin, 5% to 15% of fiber filler and 5% to 15% of viscosity reducer, and component B comprises 30% to 40% of amino-terminated polyether, 20% to 40% of modified polyphosphazene, 8% to 15% of chain extender, 10% to 20% of fiber filler, 5% to 15% of ablation-resistant resin and 5% to 15% of viscosity reducer, calculated by mass fraction.

2. The thermal insulation material according to claim 1, characterized in that: The isocyanate prepolymer is one or more of hexamethylene diisocyanate (HDI), diphenylmethane-4,4-diisocyanate (MDI), isophorone diisocyanate (IPDI) and xylylene diisocyanate (XDI).

3. The thermal insulation 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, aramid fiber and basalt fiber; the viscosity reducer is one or both of dioctyl phthalate and tri(2-ethylhexyl) phosphate.

4. The thermal insulation material according to claim 1, characterized in that: The amino-terminated polyether is one or more of CGA-T403, CGA-D2000 and CGA-T5000.

5. The thermal insulation material according to any one of claims 1 to 4, characterized in that: The modified polyphosphazene is a polyphosphazene containing hydroxyl groups and amino groups.

6. The thermal insulation material according to claim 5, characterized in that: The modified polyphosphazene preparation method comprises the following steps: The hexachlorocyclotriphosphazene is dissolved in a solvent, an ethylenediamine solution is added dropwise to react, glycerol is then added dropwise and the temperature is raised to react, and finally precipitation is carried out in methanol, and the precipitate is filtered and washed to obtain the modified polyphosphazene.

7. The thermal insulation material according to claim 6, characterized in that: The preparation of the modified polyphosphazene meets at least one of the following conditions: the solvent is anhydrous tetrahydrofuran or dichloromethane; the molar ratio of hexachlorocyclotriphosphazene, ethylenediamine and glycerol is 1:0.5-1:0.3-1.5; the reaction temperature after dropwise addition of ethylenediamine solution is 0-5°C; the temperature of the heating reaction after dropwise addition of glycerol is 40-60°C; and the total reaction time of the modified polyphosphazene is 6-12h.

8. The thermal insulation material according to claim 1, characterized in that: The chain extender is one or more of diethyltoluenediamine, dimethylthiotoluenediamine and N,N-dialkylmethyldiamine.

9. The method for preparing the thermal insulation material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Mix the raw materials of component A evenly under a protective atmosphere, and mix the raw materials of component B evenly; S2. Component A and component B are mixed, and then sprayed, and then cured to obtain a thermal insulation material.

10. The method according to claim 9, characterized in that: During curing, the sample is first cured at room temperature for 24 to 48 hours, then cured at 70 to 90°C for 48 to 72 hours; and finally cured at 110 to 130°C for 24 to 72 hours.

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