High-temperature-resistant polyhedral oligomeric silsesquioxane material and preparation method thereof

Abstract

The invention belongs to the field of organic-inorganic hybrid materials, and discloses a high-temperature-resistant polyhedral oligomeric silsesquioxane material and a preparation method thereof. According to the high-temperature-resistant polyhedral oligomeric silsesquioxane material, polyimide serves as a main chain, aminopropyl hepta-isobutyl polyhedral oligomeric silsesquioxane serves as a side chain, and a hybrid system with a clear structure is formed through chemical bonding. The obtained high-temperature-resistant polyhedral oligomeric silsesquioxane material has both the toughness of polyimide and the high-temperature stability of a cage structure, is high in thermal decomposition temperature, and is suitable for the fields of high-temperature-resistant coatings, electronic packaging, aerospace and the like. According to the method, the raw materials are low in price, wide in source channel and low in toxicity, and the obtained product is high in purity and excellent in performance and has good actual use value.

Description

Technical Field

[0001] This invention belongs to the field of organic-inorganic hybrid materials and relates to a high-temperature resistant cage-type polysilsesquioxane material and its preparation method. Background Technology

[0002] Cage-like polysilsesquioxanes are a class of nanoscale synthetic silicon-based compounds with well-defined structures. Each cage-like polysilsesquioxane molecule possesses an inorganic silicon-oxygen-silicon core and numerous organic substituent arms, which offer rich modification possibilities and can be introduced into polymers through physical blending or chemical copolymerization. Over the past two decades, cage-like polysilsesquioxane compounds have been extensively studied in polymer nanocomposites due to their inherent thermal and chemical stability, organic-inorganic hybrid structures, and designability.

[0003] The inorganic silicon-oxygen framework structure of cage-like polysilsesquioxanes endows them with excellent thermal stability, radiation resistance, and oxidation resistance. On one hand, because the Si-O bond energy is much higher than the C-C bond energy, when cage-like polysilsesquioxane molecules are bonded to the main chain or side chains of a polymer, the structure and properties of the cage-like polysilsesquioxane molecules remain stable even above the glass transition temperature or when the temperature reaches the melting point and begins to melt. On the other hand, when the organic groups on the surface of cage-like polysilsesquioxanes are oxidized and decomposed at high temperatures, because Si-O-Si is very stable to oxygen free radicals, the cage-like polysilsesquioxanes can still form a SiO2 ceramic protective layer on the polymer matrix surface after degradation, providing thermal insulation, radiation protection, and structural support.

[0004] Aromatic polyimides are aromatic heterocyclic polymers containing imide groups in their molecular backbone. They possess excellent comprehensive properties, including good thermal stability, superior mechanical properties, low dielectric constant, high breakdown voltage, low coefficient of thermal expansion, high flame retardancy, and long-term stability. Therefore, they are widely used in various high-tech fields such as electronics, aerospace, machinery, and chemical engineering. Compared to ordinary thermoplastic resins, polyimides have a high glass transition temperature (typically 200-500℃) due to the rigidity of their backbone. Consequently, they exhibit good heat resistance, oxidation resistance, and flame retardancy, and are commonly used in the manufacture of high-temperature protective clothing, gloves, insulating carpets, and high-temperature resistant materials.

[0005] Introducing cage-like polysilsesquioxanes into polyimide systems combines the advantages of both: polyimide provides toughness and film-forming properties, while the cage structure enhances thermal stability and structural retention at high temperatures. Currently, related research still focuses on physical blending, with limited systematic studies on chemically bonded hybrid materials, especially those with well-defined structures and controllable preparation processes. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature resistant cage-type polysilsesquioxane material, and another purpose is to provide a method for preparing the high-temperature resistant cage-type polysilsesquioxane material.

[0007] The technical solution of the present invention:

[0008] A high-temperature resistant cage-type polysilsesquioxane material has the following structure:

[0009] .

[0010] Among them, aminopropyl heptaisobutyl cage-type polysilsesquioxane has the following structure:

[0011] .

[0012] A method for preparing a high-temperature resistant cage-type polysilsesquioxane material includes the following steps:

[0013] (1) Under an inert atmosphere, 1,3-dihydro(3,4-dicarboxyphenoxy) phthalic anhydride, 3,3'-diaminodiphenylmethane and organic solvent A are stirred and mixed evenly, and reacted at 0℃-25℃ for 12-24h to obtain a polyamic acid solution.

[0014] (2) Add polyamic acid solution, aminopropyl heptaisobutyl cage-type polysilsesquioxane and organic solvent B into a reaction vessel and react at 120℃-160℃ for 5-12h. Wash with N-methylpyrrolidone and alcohol-water mixture with a volume ratio of 1:1 in sequence. After post-treatment, high temperature resistant cage-type polysilsesquioxane material is obtained.

[0015] The organic solvent A is preferably one of N,N-dimethylformamide, N,N-dimethylhexamamide, and N-methylpyrrolidone.

[0016] The organic solvent B is preferably one of xylene, benzene, toluene, cyclohexane, and carbon tetrachloride.

[0017] In step (1), the molar ratio of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride to 3,3'-diaminodiphenylmethane is 1:1-1:1.2, and the concentration of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride is 15-30 wt.

[0018] In step (2), the amount of aminopropyl heptaisobutyl cage-type polysilsesquioxane added is 5-20% of the mass of the polyamic acid solution.

[0019] The reaction in step (2) is carried out under a nitrogen atmosphere.

[0020] The post-treatment involves washing and drying the product after the reaction is complete; the drying temperature is 150℃-200℃ and the drying time is 3-8 hours.

[0021] The beneficial effects of this invention are:

[0022] (1) The high-temperature resistant cage-type polysilsesquioxane material of the present invention has polyimide as the main chain structure and aminopropyl heptaisobutyl cage-type polysilsesquioxane as the side chain. The temperature required for the silicon-oxygen bond to break is higher than that for the carbon-carbon bond. It decomposes into silicon dioxide. Silicon dioxide is an inorganic oxide and has the characteristics of high safety, non-toxicity, non-corrosiveness, high melting point, and strong aging resistance.

[0023] (2) The polyimide groups possess continuous high-temperature weather resistance, chemical solvent resistance, and radiation resistance, and also impart a certain degree of toughness to the material, overcoming the disadvantage of high brittleness of pure organosilicon resin, making it less prone to cracking when subjected to alternating hot and cold temperatures. In summary, the high-temperature resistant cage-type polysilsesquioxane material of this invention exhibits excellent high-temperature resistance.

[0024] (3) The raw materials used in the preparation process of this invention are inexpensive and widely available, have low toxicity, and pose no significant harm to the human body. The resulting product has high purity, excellent performance, and good practical application value. Attached Figure Description

[0025] Figure 1 The mass spectrum of the prepared aminopropyl heptaisobutyl cage-type polysilsesquioxane is shown.

[0026] Figure 2 The liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) chromatograms of the prepared 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride are shown below. (a) is a high-resolution mass spectrum of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride, (b) is an extractive ion chromatogram of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride at a mass-to-charge ratio of 403.04, and (c) is a total ion chromatogram of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride.

[0027] Figure 3 Infrared spectrum of the prepared high-temperature resistant cage-type polysilsesquioxane material;

[0028] Figure 4 Thermogravimetric analysis (TGA) of the prepared high-temperature resistant cage-type polysilsesquioxane material. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0030] Example 1

[0031] Under nitrogen protection, 10.0 g of 3,3'-diaminodiphenylmethane was dissolved in 100 mL of N,N-dimethylformamide and stirred until completely dissolved. 21.1 g of 1,3-dihydro(3,4-dicarboxyphenoxy)phthalic anhydride was added in three batches (1 hour apart), and the mixture was stirred at 0 °C for 24 hours to obtain a pale yellow polyamic acid solution.

[0032] The solution was transferred to a polytetrafluoroethylene-lined reactor, and 20 mL of xylene and 2.2 g of aminopropylheptaisobutyl cage-type polysilsesquioxane were added. The reactor was sealed and placed in an oven at 120 °C for 12 hours. After cooling, the mixture was filtered and washed successively with N-methylpyrrolidone and an alcohol-water mixture (volume ratio 1:1). Finally, it was dried at 180 °C for 8 hours to obtain a pale yellow solid product.

[0033] Example 2

[0034] Under nitrogen protection, 15 g of 3,3'-diaminodiphenylmethane was dissolved in 150 mL of N,N-dimethylhexamethylene and stirred until completely dissolved. 31.65 g of 1,3-dihydro(3,4-dicarboxyphenoxy)phenyl dianhydride was added in three batches (1 hour apart), and the mixture was stirred at 0 °C for 24 hours to obtain a pale yellow polyamic acid solution.

[0035] The solution was transferred to a polytetrafluoroethylene-lined reactor, and 30 mL of toluene and 3.3 g of aminopropylheptaisobutyl cage-type polysilsesquioxane were added. The reactor was sealed and placed in an oven at 140 °C for 8 hours. After cooling, the mixture was filtered and washed successively with N-methylpyrrolidone and an alcohol-water mixture (volume ratio 1:1). Finally, the mixture was dried at 190 °C for 6 hours to obtain a pale yellow solid product.

[0036] Example 3

[0037] Under nitrogen protection, 20 g of 3,3'-diaminodiphenylmethane was dissolved in 200 mL of N-methylpyrrolidone and stirred until completely dissolved. 42.2 g of 1,3-dihydro(3,4-dicarboxyphenoxy)phenyl dianhydride was added in three batches (1 hour apart), and the mixture was stirred at 5 °C for 12 hours to obtain a pale yellow polyamic acid solution.

[0038] The solution was transferred to a polytetrafluoroethylene-lined reactor, and 40 mL of carbon tetrachloride and 4.4 g of aminopropylheptaisobutyl cage-type polysilsesquioxane were added. The reactor was sealed and placed in an oven at 160 °C for 5 hours. After cooling, the mixture was filtered and washed successively with N-methylpyrrolidone and an alcohol-water mixture (volume ratio 1:1). Finally, the mixture was dried at 200 °C for 5 hours to obtain a pale yellow solid product.

[0039] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high temperature resistant, caged polysilsesquioxane material, characterized in that, A high-temperature-resistant cage-type polysilsesquioxane material has a structure as follows: ； The aminopropyl heptaisobutyl cage-type polysilsesquioxane has a structure as follows: 。 2. A method for producing a high temperature resistant, caged polysilsesquioxane material, characterized by, The method comprises the following steps: (1) Under an inert atmosphere, 1,3-dihydro(3,4-dicarboxyphenoxy)benzene dianhydride, 3,3'-diaminodiphenyl methane and an organic solvent A are stirred and mixed uniformly, and reacted at 0-25°C for 12-24 hours to obtain a polyamic acid solution; (2) The polyamic acid solution, the aminopropyl heptaisobutyl cage-type polysilsesquioxane and an organic solvent B are added into a reaction kettle, and reacted at 120-160°C for 5-12 hours, and then washed with N-methyl pyrrolidone and an alcohol-water mixture with a volume ratio of 1:1, and aftertreated to obtain the high-temperature-resistant cage-type polysilsesquioxane material.

3. The preparation method according to claim 2, wherein the organic solvent A is preferably one of N,N-dimethylformamide, N,N-dimethylhexanamide and N-methyl pyrrolidone.

4. The preparation method according to claim 2, wherein the organic solvent B is preferably one of dimethylbenzene, benzene, toluene, cyclohexane and carbon tetrachloride.

5. The preparation method according to claim 2, wherein in step (1), the molar ratio of 1,3-dihydro(3,4-dicarboxyphenoxy)benzene dianhydride to 3,3'-diaminodiphenyl methane is 1:1-1:1.2, and the concentration of 1,3-dihydro(3,4-dicarboxyphenoxy)benzene dianhydride is 15-30 wt%.

6. The preparation method according to claim 2, wherein in step (2), the addition amount of the aminopropyl heptaisobutyl cage-type polysilsesquioxane is 5-20% of the mass of the polyamic acid solution.

7. The preparation method according to claim 2, wherein the reaction in step (2) is carried out under a nitrogen atmosphere.

8. The preparation method according to claim 2, wherein the aftertreatment is washing and drying treatment of the product after the reaction; the drying temperature is 150-200°C, and the drying time is 3-8 hours. ​ ​ ​ ​ ​ ​

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