Trapezoidal polyphenyl silsesquioxane radiation-resistant additive and preparation method thereof

Abstract

The invention provides a trapezoidal polyphenyl silsesquioxane radiation-resistant additive and a preparation method thereof, and a method for preparing the trapezoidal polyphenyl silsesquioxane radiation-resistant additive # imgabs0 #. The method comprises the following steps: preparing a first intermediate, preparing a second intermediate, synthesizing and blocking. The polyphenyl silsesquioxane radiation-resistant additive containing the trapezoidal structure has more aromatic rings, the aromatic rings contain conjugated double bonds, radiation energy can be absorbed, the radiation resistance of phenyl silicone rubber can be remarkably improved, meanwhile, the main chain of the molecular structure of the radiation-resistant additive is of a silicon-oxygen-silicon structure, and the molecular structure of the radiation-resistant additive is uniform. The structure has good compatibility with silicone rubber, and the physical and mechanical properties of the phenyl silicone rubber material are not affected.

Description

Technical Field

[0001] The present invention discloses a special rubber functional material and its production technology field, and relates to a radiation-resistant additive of trapezoidal polyphenylsilsesquioxane and a preparation method thereof, and is particularly suitable for preparing a radiation-resistant additive for radiation-resistant silicone rubber. Background Art

[0002] Countries around the world generally attach importance to the development and utilization of energy. As a safe, clean and reliable energy source, the development and utilization of nuclear power is increasingly valued. In order to ensure the safety of nuclear power equipment, a large number of polymer elastomer sealing materials are used in the electrical instruments, wire and cable insulation materials, gasket seals, etc. in the equipment. This type of sealing material not only needs to have sufficient radiation resistance, but also needs to be able to withstand harsh environmental conditions such as high temperature, vacuum, high voltage, steam, and various chemical media. However, some polymers with excellent high temperature resistance and chemical resistance may not be able to withstand radiation, such as ordinary dimethyl silicone rubber. Although dimethyl silicone rubber has a wide applicable temperature range and good dielectric resistance and electrical properties, its radiation resistance is not as good as that of general hydrocarbon rubbers. Dimethyl silicone rubber is subjected to 12.9~15.48×103C / kg (5~6×10 7 After being irradiated, it will lose its elasticity. The radiation resistance of specially formulated methyl vinyl silicone rubber can only reach about 2.58×104C / kg (1×10 8 Therefore, it is necessary to find ways to improve the radiation resistance of silicone rubber.

[0003] As early as the 1950s, Robert discovered that the radiation resistance of phenyl-containing silicone rubber was significantly better than that of methyl silicone rubber. Tragcr found that after being subjected to the same irradiation, the crosslinking density and dynamic mechanical properties of phenyl-containing polysiloxane changed very little after irradiation, indicating that phenyl effectively reduced the radiation effect of the polymer main chain. This is because the huge aromatic ring contains conjugated double bonds, which can absorb radiation energy and make the polymer material stable. Therefore, the appropriate introduction of phenyl groups into silicone rubber molecules is expected to improve the radiation resistance of silicone rubber materials. Chinese patent CN100480333C and US patents US3032531, US3876605, US5196228A, etc. all use phenyl silicone rubber as raw rubber to prepare rubber with radiation resistance, which indeed improves the radiation resistance of silicone rubber. Its radiation resistance can reach 5×10 8 However, facing the current higher demand for radiation resistance, it is necessary to further improve the radiation resistance of phenyl silicone rubber. Summary of the invention

[0004] The purpose of the present invention is to provide a radiation-resistant additive with a trapezoidal polyphenylsilsesquioxane structure and a synthesis process thereof. The radiation-resistant silicone rubber material prepared with the additive can be used as a sheath for radiation-resistant and high-temperature-resistant lead-out wires in nuclear power plants, and can also be used alone or in combination with fabrics to make rubber clamps, rubber gaskets, rubber sleeves and various radiation-resistant profiles.

[0005] The technical solution of the present invention is:

[0006] Provide ladder-shaped polyphenyl silsesquioxane radiation-resistant additives, the molecular formula structure is:

[0007]

[0008] The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive comprises the following steps:

[0009] Step 1: Preparation of the first intermediate

[0010] Fully mix methanol, deionized water and hydrochloric acid to obtain a drop solution; drop the drop solution into phenyltrimethoxysilane to obtain a first mixed solution, and stir while dropping, with the dropping time being shorter than the stirring time; after sufficient stirring, vacuum distill the first mixed solution to obtain a colorless oily liquid, which is 1,3-diphenyl-1,1,3,3-tetramethoxydisiloxane and serves as a first intermediate;

[0011] Step 2: Preparation of the second intermediate

[0012] At 0°C to 10°C, the first intermediate is added to an ether solution to obtain a second mixed solution, the second mixed solution is added dropwise to an acetic acid aqueous solution, stirring is started while the addition is started, and the mixture is allowed to stand for stratification after stirring to obtain an ether mixed solution; deionized water is added to the ether mixed solution at least once, and the mixture is allowed to stand for stratification after each addition of deionized water is fully stirred, and the lower layer of liquid is drained to retain only the upper layer of the ether mixed solution (to wash away unreacted acetic acid);

[0013] Add anhydrous sodium sulfate to the ether mixture to remove residual water in the ether mixture, and then filter to remove the sodium sulfate;

[0014] The ether mixture is distilled under nitrogen protection to remove low-boiling ether to obtain crystals; ether is added dropwise to the crystals to form a saturated dissolved state, and then mixed with n-hexane, wherein the volume ratio of the added ether to n-hexane is 1:5-10; the mixture is fully mixed and extracted to obtain a precipitate, which is 1,3-diphenyl-1,1,3,3-tetrahydroxydisiloxane; the precipitate is used as the second intermediate:

[0015] Step 3: Synthesis

[0016] The second intermediate is dissolved in a mixed solution of acetonitrile and toluene, and then stirred for 1 to 3 hours, and triethylamine is added dropwise and stirred for 5 to 24 hours. After sufficient reaction, the mixed solution is distilled under reduced pressure to obtain a white solid;

[0017] Step 4: End-capping

[0018] The white solid is dissolved in toluene to form a reaction solution, triethylamine is added dropwise to the reaction solution, and the mixture is stirred at 30°C to 50°C for 5 to 24 hours; a toluene solution of trimethylchlorosilane is added to the reaction solution, and a capping reaction is carried out at 30°C to 50°C for 3 to 6 hours, and the insoluble gel is removed by filtration to obtain a filtrate; the filtrate is added to methanol to obtain a precipitate, and the precipitate is the trapezoidal polyphenylsilsesquioxane radiation-resistant additive.

[0019] Furthermore, in step 1, methanol is the solvent of the dropwise solution, and hydrochloric acid is the catalyst for the hydrolysis reaction, with a concentration of 1 mol / L. Furthermore, the molar ratio of deionized water to phenyltrimethoxysilane is 1:2-3.

[0020] Furthermore, the dropping temperature in step 1 is controlled at 23° C. to 25° C., the dropping time in step 1 is 1 to 3 hours, and the stirring time is 5 to 24 hours.

[0021] Furthermore, the molar concentration of the acetic acid aqueous solution in step 2 is 0.5 mol / L.

[0022] Furthermore, the dropping temperature in step 2 is controlled at 0°C to 10°C. In step 2, when the second mixed solution is added dropwise to the acetic acid aqueous solution, the dropping time is 1 to 3 hours and the stirring time is 5 to 24 hours.

[0023] Furthermore, the dropping temperature in step 3 is controlled at 0° C., the dropping time in step 3 is 1 to 3 hours, and the stirring time is 5 to 24 hours. In step 3, triethylamine is a catalyst.

[0024] Furthermore, the concentration of trimethylchlorosilane in step 4 is 0.1 mol / L.

[0025] The advantages and beneficial effects of the present invention are:

[0026] The radiation-resistant additive of the present invention containing a ladder-shaped structure of polyphenyl silsesquioxane itself has a large number of aromatic rings, and the aromatic rings contain conjugated double bonds, which can absorb radiation energy and further improve the radiation resistance of phenyl silicone rubber. At the same time, the main chain of the molecular structure of the radiation-resistant additive is a silicon-oxygen-silicon structure, which has good compatibility with silicone rubber and does not affect the physical and mechanical properties of the phenyl silicone rubber material.

[0027] The radiation-resistant silicone rubber material prepared by the present invention can be used to produce various types of rubber products such as wires, cable sheaths, rubber gaskets, sealing parts, diaphragms, etc. for various radiation occasions, and can be widely used in aerospace, nuclear industry, electronic communications, chemical industry, medicine, shipbuilding and other fields that require resistance to high-energy radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The product structure is shown by infrared spectrum; in the infrared spectrum, 3050cm -1 and 3073cm -1 The peak is the CH stretching vibration peak of the phenyl group, 1439 cm -1 、1490cm -1 and 1594cm -1 The peak at 1132 cm is the stretching vibration peak of the C=C double bond skeleton on the phenyl group. -1 and 1042cm -1 The peak is the Si-O-Si stretching vibration peak.

[0029] Figure 2 The NMR spectrum of the product structure. The NMR silicon spectrum has a single peak at -61ppm, which is obviously attributed to the silicon connected to the phenyl group in the ladder polymer. Due to the high molecular weight and low end group content, the peak indicated by the terminal trimethylsilyl group was not found on the silicon spectrum, indicating that the obtained product has high purity. The infrared and NMR results show that the target product was successfully obtained. Specific implementation methods

[0031] The disclosed examples will be more fully described with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples can be described and these examples should not be construed as limited to the examples set forth herein. Instead, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. :

[0032] Provide ladder-shaped polyphenyl silsesquioxane radiation-resistant additives, the molecular formula structure is:

[0033]

[0034] The radiation-resistant additive is used for preparing radiation-resistant rubber, as an additive for preparing radiation-resistant rubber.

[0035] The preparation method of the radiation-resistant additive providing a ladder-shaped polyphenylsilsesquioxane structure is as follows:

[0036] (1) Preparation of the first intermediate

[0037] In a 1000ml round-bottom flask, a mixed solution of 80ml methanol, 10.8ml deionized water and 0.3ml hydrochloric acid was slowly added dropwise to 317.3g phenyltrimethoxysilane, the dropping temperature was controlled at 23°C, the dropping time was about 2h, and then stirred at 23°C for 24h. The mixture was distilled under reduced pressure, and a colorless oily liquid (128-130°C / 1.0mmHg) was collected to obtain intermediate 1: 96g of 1,3-diphenyl-1,1,3,3-tetramethoxydisiloxane.

[0038] (2) Preparation of the second intermediate

[0039] At 10°C, the first intermediate is added to 400ml of ether solution to obtain a second mixed solution, and the second mixed solution is added dropwise to 60ml of 0.5mol / L acetic acid aqueous solution, and stirring is started at the same time, and the dropping time is about 3h. Stir at 10°C for 24h, and stand to separate after stirring to obtain an ether mixed solution; add deionized water to the ether mixed solution at least once, stir thoroughly after each addition of deionized water, and stand to separate, and drain the lower layer of liquid to retain only the upper layer of ether mixed solution (to wash away unreacted acetic acid);

[0040] Add anhydrous sodium sulfate to the ether mixture to remove residual water in the ether mixture, and then filter to remove the sodium sulfate;

[0041] The ether mixture is distilled under nitrogen protection to remove low-boiling ether to obtain crystals; ether is added dropwise to the crystals to form a saturated dissolved state, and the ether mixture of the crystals in the saturated dissolved state is mixed with n-hexane, and the volume ratio of the added ether to n-hexane is 1:5; the precipitate is fully mixed and extracted to obtain a precipitate, and the obtained precipitate is 1,3-diphenyl-1,1,3,3-tetrahydroxydisiloxane; the precipitate is used as the second intermediate 54g.

[0042] (3) Product Synthesis

[0043] At 0°C, the second intermediate was dissolved in a mixed solution of 400 ml of acetonitrile and toluene (volume ratio 1:2), stirred for 1 hour, and then 20 ml of triethylamine was added dropwise to the mixed solution. The reaction solution was then stirred at 0°C for 24 hours, and after sufficient reaction, the mixed solution was distilled under reduced pressure to obtain a white solid;

[0044] (4) End-capping

[0045] The white solid was dissolved in 400 ml of toluene, 2 ml of triethylamine was added dropwise, and then stirred at 50°C for 24 h. Finally, 10 ml of a toluene solution of trimethylsilyl chloride (0.1 mol / L) was added to the above reaction solution, and the end-capping reaction was continued for 6 h. The obtained reaction solution was filtered to remove the insoluble gel, and the filtrate was precipitated in methanol and filtered to obtain 38 g of a white trapezoidal polyphenylsilsesquioxane polymer.

[0046] The steps of the method for preparing radiation-resistant silicone rubber using the components of the formula in Table 1 are:

[0047] (1) Preparation of rubber compound sheets

[0048] Put 100 parts by weight of phenyl silicone rubber raw rubber on a double-roll rubber mixer, add 5-25 parts of a trapezoidal polyphenyl silsesquioxane radiation-resistant additive, 30-60 parts of white carbon black and 0-15 parts of a structure control agent after rolling, mix evenly and then thin out a sheet;

[0049] (2) Adding vulcanizing agent

[0050] Place the mixed rubber sheet on a double-roll rubber mixer, add 0.5-1.2 parts of vulcanizing agent after rolling, mix evenly and then put the sheet aside for use;

[0051] (3) Vulcanization molding of rubber

[0052] The first stage of vulcanization is carried out on a pressure molding machine under the conditions of 90-170°C for 10 minutes; the second stage of vulcanization is carried out in an oven under the conditions of 200°C for 4 hours to form radiation-resistant silicone rubber products of the required shape.

[0053] The physical and mechanical properties of the radiation-resistant silicone rubber samples prepared by the formula components listed in Table 1. Among them, 1) Mechanical properties test: tensile strength and elongation at break are tested according to GB / T 528; hardness is tested according to GB / T 531; 2) Co60 is used as the irradiation energy source, and the samples are subjected to 1×10 9 The test results are shown in Table 1.

[0054] The description of different advantageous arrangements has been presented for purposes of illustration and description, but the description is not intended to be exclusive or limited to examples of the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. Additionally, different advantageous examples may describe different advantages over other advantageous examples. The selected example or examples are chosen and described in order to best illustrate the principles of the examples, the practical application, and to enable those of ordinary skill in the art to understand the disclosure with various examples with various modifications suitable for the particular use contemplated.

Claims

1. A trapezoidal polyphenylsilsesquioxane radiation-resistant additive, characterized in that: The molecular formula structure is:

2. A method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive, characterized in that: The steps include: Step 1: Preparation of the first intermediate Fully mix methanol, deionized water and hydrochloric acid to obtain a drop solution; drop the drop solution into phenyltrimethoxysilane to obtain a first mixed solution, and stir while dropping, with the dropping time being shorter than the stirring time; after sufficient stirring, vacuum distill the first mixed solution to obtain a colorless oily liquid, which is 1,3-diphenyl-1,1,3,3-tetramethoxydisiloxane and serves as a first intermediate; Step 2: Preparation of the second intermediate At 0°C to 10°C, adding the first intermediate to an ether solution to obtain a second mixed solution, dropping the second mixed solution into an acetic acid aqueous solution, stirring while starting the dropping, and standing to separate after stirring to obtain an ether mixed solution; adding deionized water to the ether mixed solution at least once, stirring thoroughly each time deionized water is added, standing to separate, and draining the lower layer of liquid to retain only the upper layer of the ether mixed solution; Add anhydrous sodium sulfate to the ether mixture to remove residual water in the ether mixture, and then filter to remove the sodium sulfate; The ether mixture is distilled under nitrogen protection to remove low-boiling ether to obtain crystals; ether is added dropwise to the crystals to form a saturated dissolved state, and then mixed with n-hexane, wherein the volume ratio of the added ether to n-hexane is 1:5-10; the mixture is fully mixed and extracted to obtain a precipitate, which is 1,3-diphenyl-1,1,3,3-tetrahydroxydisiloxane; the precipitate is used as the second intermediate: Step 3: Synthesis The second intermediate is dissolved in a mixed solution of acetonitrile and toluene, and then stirred for 1 to 3 hours, and triethylamine is added dropwise and stirred for 5 to 24 hours. After sufficient reaction, the mixed solution is distilled under reduced pressure to obtain a white solid; Step 4: End-capping The white solid is dissolved in toluene to form a reaction solution, triethylamine is added dropwise to the reaction solution, and the mixture is stirred at 30°C to 50°C for 5 to 24 hours; a toluene solution of trimethylchlorosilane is added to the reaction solution, and a capping reaction is carried out at 30°C to 50°C for 3 to 6 hours, and the insoluble gel is removed by filtration to obtain a filtrate; the filtrate is added to methanol to obtain a precipitate, and the precipitate is the trapezoidal polyphenylsilsesquioxane radiation-resistant additive.

3. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: In step 1, methanol is the solvent of the dropwise solution, and hydrochloric acid is the catalyst for the hydrolysis reaction, with a concentration of 1 mol / L. Furthermore, the molar ratio of deionized water to phenyltrimethoxysilane is 1:2-3.

4. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: The dropping temperature in step 1 is controlled at 23° C. to 25° C., the dropping time in step 1 is 1 to 3 hours, and the stirring time is 5 to 24 hours.

5. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: The molar concentration of the acetic acid aqueous solution in step 2 is 0.5 mol / L.

6. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: The dropping temperature in step 2 is controlled at 0°C to 10°C. In step 2, when the second mixed solution is added dropwise to the acetic acid aqueous solution, the dropping time is 1 to 3 hours and the stirring time is 5 to 24 hours.

7. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: The dropping temperature in step 3 is controlled at 0° C., the dropping time in step 3 is 1 to 3 hours, and the stirring time is 5 to 24 hours. In step 3, triethylamine is a catalyst.

8. The method for preparing a trapezoidal polyphenylsilsesquioxane radiation-resistant additive according to claim 2, characterized in that: The concentration of trimethylchlorosilane in step 4 is 0.1 mol / L.

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