CN110078927A - A kind of heat-resisting boracic containing hydrogen silicone oil and preparation method - Google Patents

Abstract

The invention relates to a heat-resistant boron-containing hydrogen-containing silicone oil. The number average molecular weight of the heat-resistant boron-containing hydrogen-containing silicone oil is 8000-10000; in the thermogravimetric analysis test, under air conditions, the temperature at which it loses 5% of its weight is 380-400°C; under nitrogen conditions, the temperature at which it loses 5% of its weight The temperature is 450‑470°C. The present invention improves the service temperature of the silicone oil by introducing phenylboronic acid and phenylsilane on the basis of ordinary hydrogen-containing silicone oil, while maintaining the activity of Si-H bonds. When the temperature is raised in the air, due to the symmetrical distribution of the phenyl groups in the boron-containing phenylhydrogen silicone oil, it can dissipate heat through the free rotation of single bonds and increase its own heat-resistant temperature; the bond energy of the boron-oxygen bond is 537.6 kJ mol ^{‑ 1} is much larger than the bond energy 422.5kJ·mol ^‑1 of the silicon-oxygen bond, which can absorb more heat and then decompose; at the same time, the boron atoms on the main chain have empty electron orbits that can form intermolecular bonds with oxygen atoms on other chains Coordinate bonds, to obtain temporarily stable intermediates, improve thermal stability. The invention adopts a hydrolysis method to prepare heat-resistant boron-containing hydrogen-containing silicone oil, and the method and process are simple.

Description

A kind of heat-resistant boron-containing hydrogen-containing silicone oil and preparation method thereof

technical field

The invention belongs to the technical field of polymer materials, and in particular relates to a heat-resistant boron-containing hydrogen-containing silicone oil and a preparation method thereof.

Background technique

Silicone oils generally refer to linear polysiloxane products that remain liquid at room temperature. It is generally divided into two types: methyl silicone oil and modified silicone oil. Hydrogen-containing silicone oil in modified silicone oil has been widely used in daily life due to its excellent characteristics. Hydrogen-containing silicone oil has particularly excellent hydrophobicity and is suitable for surface treatment of glass, fiber, and powder. Under the action of metal salt catalysts, it can be cross-linked at low temperature to form a waterproof film on the surface of various substances. It can be used as fabric, paper, Water repellent for various materials such as leather and cement, solid silicone rubber-mixed silicone rubber as a bridging agent, anti-yellowing agent, coupling agent, and as a crosslinking agent for addition-type liquid silicone rubber.

At this stage, the domestic market has higher requirements for the use conditions of hydrogen-containing silicone oil: it can exist stably at high temperature and has certain reactivity. Modified hydrogen-containing silicone oil has broad development prospects in the mixing of high-temperature silicone rubber and the development of waterproofing agents for glass and ceramic materials.

There are two ways of thermal decomposition of polysiloxane: free radical oxidation of side chain groups and breaking of main chain structure into small molecule cyclic oligomers. It can be used as a coupling agent for high-temperature mixing silicone rubber, as a cross-linking agent for addition-type silicone rubber, and as a waterproofing agent in the textile and clothing industries.

SUMMARY OF THE INVENTION

In order to increase the use temperature of hydrogen-containing silicone oil and maintain the activity of Si-H bonds, the invention provides a heat-resistant boron-containing hydrogen-containing silicone oil; meanwhile, the invention provides a preparation method of heat-resistant boron-containing hydrogen-containing silicone oil.

The invention modifies the hydrogen-containing silicone oil to obtain the heat-resistant boron-containing hydrogen-containing silicone oil with excellent thermal stability.

The structural formula of the heat-resistant boron-containing hydrogen-containing silicone oil is as follows:

Wherein, R ₁ , R ₂ , R ₃ are methyl or phenyl;

a, b, c, and d are phenylboronic acid, methylhydrogendichlorosilane, diphenyldichlorosilane, and dimethyldichlorosilane, respectively, and a:b:c:d is 2:1:1:6;

The number average molecular weight of the heat-resistant boron-containing hydrogen-containing silicone oil is 8000-10000;

According to thermogravimetric analysis, under air conditions, the temperature at which it loses 5% of its weight is 390-410°C; under nitrogen, the temperature at which it loses 5% of its weight is 450-470°C.

The operation steps for preparing heat-resistant boron-containing hydrogen-containing silicone oil are as follows:

Step (1): Making the end group is boron hydroxyl hydrogen-containing silicone oil

Add 100 mL of solvent A to 30-40 g of phenylboronic acid to dissolve, and the solvent A is toluene or ether;

Slowly add 20-40g methylhydrogendichlorosilane, 50-80g diphenyldichlorosilane, 160-200g dimethyldichlorosilane dropwise sequentially;

Add 30mL of concentrated sulfuric acid (catalyst) with a mass fraction of 60%, react in a nitrogen atmosphere at 20-30°C for 6h, raise the temperature to 80-90°C for another 6-8h, cool, and separate toluene or ether substances with a separatory funnel. Collect the first crude oil phase;

Add 60mL of inorganic salt solution to the first crude oil phase to remove the residual catalyst, separate with a separatory funnel, wash and separate the oil phase with 100ml of ethanol, and obtain 150-200g of boron-containing silicone oil oligomer;

Step (2): End-capping of heat-resistant boron-containing hydrogen-containing silicone oil

Take 15-25g boron-containing silicone oil oligomer, add 100-120mL solvent B to dissolve, and the solvent B is toluene or amide;

Add 0.5-2g end-capping agent, then add 10mL concentrated sulfuric acid (catalyst) with a mass fraction of 60%, react with nitrogen gas at 100-110°C for 3-4h, and cool to obtain a blocked boron-containing hydrogen-containing silicone oil;

Add 60 mL of inorganic salt solution to the blocked boron-containing hydrogen-containing silicone oil to adjust the pH value to 6-7, separate with a separatory funnel, and collect the second crude oil phase;

The toluene or amide substances in the second crude oil phase are removed under reduced pressure to obtain a purified heat-resistant boron-containing hydrogen-containing silicone oil.

Further defined technical solutions are as follows:

The solvent A is one of diglyme, toluene and xylene.

In step (1) or step (2), the inorganic salt solution is a saturated sodium carbonate solution or a saturated sodium bicarbonate solution.

In step (2), the solvent B is one of toluene, N,N-dimethylformamide and xylene.

In step (2), the end-capping agent is one of hexamethyldisilazane and triphenylsilyl chloride.

Beneficial technical effect of the present invention is embodied in the following aspects:

1. This invention improves the use temperature of silicone oil by introducing phenylboronic acid and phenylsilane on the basis of ordinary hydrogen-containing silicone oil, while maintaining the activity of Si-H bond. When the temperature is raised in the air, due to the symmetrical distribution of the phenyl groups in the boron-containing phenylhydrogen silicone oil, it can dissipate heat through the free rotation of single bonds and improve its own heat-resistant temperature; the bond energy of the boron-oxygen bond is 537.6kJ·mol ^{- 1} is much larger than the bond energy 422.5 kJ mol ^-1 of the silicon-oxygen bond, which can absorb more heat and then decompose; at the same time, the boron atoms on the main chain have empty electron orbits, which can form intermolecular bonds with oxygen atoms on other chains Coordinate bonds, resulting in temporarily stable intermediates, thereby improving thermal stability. Using thermogravimetric analysis test, the heat-resistant boron-containing hydrogen-containing silicone oil of the present invention has a temperature of 5% weight loss of 390-410°C under air conditions; and a temperature of 5% weight loss of 450-470°C under nitrogen conditions; Coupling agent for high-temperature mixing silicone rubber, cross-linking agent for addition-type silicone rubber, and waterproofing agent in textile and clothing industries.

2. The present invention adopts the hydrolysis method to prepare heat-resistant boron-containing hydrogen-containing silicone oil. The method is simple, the monomer is cheap, the source is wide, and the operation is simple. The produced by-product hydrogen chloride can be collected as the raw material for the production of chlorosilane monomer, so as to realize the circulation of raw materials use.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail through the following examples. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. However, it should be understood that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Example 1

The preparation operation steps of a heat-resistant boron-containing hydrogen-containing silicone oil are as follows:

Step (1): Preparation of hydrogen-containing silicone oil with borohydroxyl terminal group

Weigh 30.48g (0.25mol) of phenylboronic acid, add 100mL solvent diethylene glycol dimethyl ether to dissolve; slowly add 28.75g (0.25mol) methylhydrogendichlorosilane, 63.25g (0.25mol) Phenyldichlorosilane and 193.5g (1.5mol) dimethyldichlorosilane, add 30mL concentrated sulfuric acid with a mass fraction of 60% as a catalyst, pass through a condensation device and nitrogen under mechanical stirring, and react at 30°C for 6h in a nitrogen atmosphere , then heated up to 90°C for another 8 hours, cooled, separated by a separatory funnel, and collected the first crude oil phase; 60ml of saturated sodium carbonate solution was added to the first crude oil phase to remove residual catalyst, and the separatory funnel separated the solvent diethylene glycol Dimethyl ether, the oil phase was washed with 100ml ethanol and separated to obtain 180g of boron-containing silicone oil oligomers with hydroxyl groups at the end;

Step (2): End-capping of heat-resistant boron-containing hydrogen-containing silicone oil

Weigh 20g of the hydrogen-containing oligomer with a benzene ring in the side chain of step (1) and dissolve it in 100mL of solvent toluene, add 0.6g of hexamethyldisilazane as an end-capping agent, and then add 10mL with a mass fraction of 60% sulfuric acid was used as a catalyst, nitrogen was continuously passed, reacted at 100°C for 4 hours, cooled, added 60mL saturated sodium carbonate solution to adjust the pH value to 6-7, separated by a separatory funnel, collected the second crude oil phase, and removed the solvent toluene under reduced pressure. 15-18g of end-capped heat-resistant boron-containing hydrogen-containing silicone oil was obtained.

The molecular weight of the prepared heat-resistant boron-containing hydrogen-containing silicone oil was determined to be 8500 by gel permeation chromatography (molecular weight is relative to polystyrene standard, the eluent is tetrahydrofuran, and the flow rate is 0.8mL/min). Under air conditions, the initial decomposition The temperature is 380°C, under the condition of nitrogen, the initial decomposition temperature is 460°C, and it contains obvious Si-H bond absorption peak as measured by Fourier transform infrared spectrometer. And using the absorption of Si-H bond in hydrogen-containing silicone oil at 2150cm ^-1 , carbon tetrachloride was used as solvent to measure the absorbance value, and the hydrogen content of the sample was obtained as 1.5% according to the calibration curve.

Example 2

The preparation operation steps of a heat-resistant boron-containing hydrogen-containing silicone oil are as follows:

Step (1): Preparation of hydrogen-containing silicone oil with borohydroxyl terminal group

Weigh 30.48g (0.25mol) of phenylboronic acid, add 100mL solvent diethylene glycol dimethyl ether to dissolve; slowly add 34.50g (0.30mol) methylhydrogen dichlorosilane, 75.90g (0.30 mol) diphenyldichlorosilane and 161.25g (1.25mol) dimethyldichlorosilane, add 30mL concentrated sulfuric acid with a mass fraction of 60% as a catalyst, pass through a condensing device and nitrogen under mechanical stirring, in a nitrogen atmosphere at 30°C React at low temperature for 6 hours, then raise the temperature to 90°C for another 8 hours, cool, separate the first crude oil phase with a separatory funnel, and collect the first crude oil phase; add 60 mL of saturated sodium carbonate solution to the first crude oil phase to remove residual catalyst, and separate the solvent with a separatory funnel Diethylene glycol dimethyl ether, the oil phase was washed with 100mL ethanol, and separated to obtain 190g of boron-containing silicone oil oligomers with hydroxyl groups at the end;

Step (2): End-capping of heat-resistant boron-containing hydrogen-containing silicone oil

Weigh 20g of the hydrogen-containing oligomer with a benzene ring in the side chain of step (1) and dissolve it in 100mL of solvent toluene, add 0.8g of hexamethyldisilazane as an end-capping agent, and then add 10mL of 60% sulfuric acid as a catalyst, continue to flow nitrogen, react at 100°C for 4 hours, cool, add 60mL saturated sodium carbonate solution to adjust the pH value to 6-7, separate with a separatory funnel, collect the second crude oil phase, and remove the solvent toluene under reduced pressure , to obtain 15-16g of end-capped heat-resistant boron-containing hydrogen-containing silicone oil;

The molecular weight of the prepared heat-resistant boron-containing hydrogen-containing silicone oil was determined to be 9000 by gel permeation chromatography (the molecular weight is relative to polystyrene standard, the eluent is tetrahydrofuran, and the flow rate is 0.8mL/min). Under air conditions, the initial decomposition The temperature is 390°C, under the condition of nitrogen, the initial decomposition temperature is 465°C, and it contains obvious Si-H bond absorption peak as measured by Fourier transform infrared spectrometer. And using the absorption of Si-H bond in hydrogen-containing silicone oil at 2150cm ^-1 , carbon tetrachloride was used as solvent to measure the absorbance value, and the hydrogen content of the sample was obtained as 1.8% according to the calibration curve.

Example 3

The preparation operation steps of a heat-resistant boron-containing hydrogen-containing silicone oil are as follows:

Step (1): Preparation of hydrogen-containing silicone oil with borohydroxyl terminal group

Weigh 36.30g (0.3mol) of phenylboronic acid, add 100mL solvent diethylene glycol dimethyl ether to dissolve; slowly add 23.00g (0.20mol) methylhydrogen dichlorosilane, 50.60g (0.20mol ) diphenyldichlorosilane and 193.50g (1.50mol) dimethyldichlorosilane, add 30mL concentrated sulfuric acid with a mass fraction of 60% as a catalyst, pass through a condensation device and nitrogen under mechanical stirring, and in a nitrogen atmosphere at 30 ° C React for 6 hours, then heat up to 90°C for another 8 hours, cool, separate with a separatory funnel, and collect the first crude oil phase; add 60ml of saturated sodium carbonate solution to the first crude oil phase to remove residual catalyst, and separate the solvent diethyl ether with a separatory funnel Glyme, the oil phase was washed with 100mL ethanol, and separated to obtain 160g of boron-containing silicone oil oligomers with hydroxyl groups at the end;

Step (2): End-capping of heat-resistant boron-containing hydrogen-containing silicone oil

Weigh 20g of the hydrogen-containing oligomer with a benzene ring in the side chain of step (1) and dissolve it in 100mL of solvent toluene, add 1.51g of triphenylsilyl chloride as an end-capping agent, and then add 10mL with a mass fraction of 60 % sulfuric acid as a catalyst, continue nitrogen flow, react at 100°C for 4h, cool, add 60ml saturated sodium carbonate solution to adjust the pH value to 6-7, separate with a separatory funnel, collect the second crude oil phase, remove the solvent toluene under reduced pressure to obtain 15 -17g end-capped heat-resistant boron-containing hydrogen-containing silicone oil;

The molecular weight of the prepared heat-resistant boron-containing hydrogen-containing silicone oil was determined to be 9500 by gel permeation chromatography (the molecular weight is relative to the polystyrene standard, the eluent is tetrahydrofuran, and the flow rate is 0.8mL/min). Under air conditions, the initial decomposition The temperature is 395°C, and under the condition of nitrogen, the initial decomposition temperature is 455°C, and it contains obvious Si-H bond absorption peaks as determined by Fourier transform infrared spectrometer. And using the absorption of Si-H bond in hydrogen-containing silicone oil at 2150cm ^-1 , carbon tetrachloride was used as solvent to measure the absorbance value, and the hydrogen content of the sample was obtained as 1.4% according to the calibration curve.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement or improvement made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (6)

1. a kind of heat-resisting boracic containing hydrogen silicone oil, it is characterised in that structural formula is as follows:

Wherein, R₁、R₂、R₃For methyl or phenyl；

A, b, c, d are respectively phenyl boric acid, methyl hydrogen dichlorosilane, diphenyl dichlorosilane, dimethyldichlorosilane, a:b:c:d For 2:1:1:6；

The number-average molecular weight of the heat-resisting boracic containing hydrogen silicone oil is 8000-10000；

Thermogravimetric analysis test, under air conditions, the temperature of weightlessness 5% is 390-410 DEG C；Under a nitrogen atmosphere, weightlessness 5% Temperature be 450-470 DEG C.

2. preparing a kind of method of heat-resisting boracic containing hydrogen silicone oil described in claim 1, it is characterised in that operating procedure is as follows:

Step (1): production end group is boron hydroxyl hydrogen silicone oil

The dissolution of 100mL solvent A is added in 30-40g phenylboric acid, the solvent A is toluene or ether material；

20-40g methyl hydrogen dichlorosilane, 50-80g diphenyl dichlorosilane, 160-200g dimethyl dichloro is successively slowly added dropwise Silane；

The concentrated sulfuric acid (catalyst) of 30mL mass fraction 60% is added, reacts 6h at 20-30 DEG C in nitrogen atmosphere, is warming up to 80- 90 DEG C are reacted 6-8h again, cooling, and separatory funnel separation of methylbenzene or ether material collect the first crude oil phase；

60mL inorganic salt solution is added in first crude oil phase and removes residual catalyst, separatory funnel separation, oil mutually uses 100mL ethyl alcohol It washs, separate, obtaining 150-200g boracic silicone oil oligomer；

Step (2): the sealing end of heat-resisting boracic containing hydrogen silicone oil

15-25g boracic silicone oil oligomer is taken, 100-120mL solvent B dissolution is added, the solvent B is toluene class or amides object Matter；

0.5-2g end-capping reagent is added, adds the concentrated sulfuric acid (catalyst) of 10mL mass fraction 60%, leads to nitrogen at 100-110 DEG C 3-4h is reacted, cooling, the boracic containing hydrogen silicone oil blocked；

60mL inorganic salt solution is added in boracic containing hydrogen silicone oil and adjusts pH value to 6-7, the second crude oil is collected in separatory funnel separation Phase；

Toluene class or amide substance in decompression the second crude oil phase of removal, the heat-resisting boracic containing hydrogen silicone oil purified.

3. preparation method according to claim 2, it is characterised in that: in step (1), the solvent A is diethylene glycol two At least one of methyl ether, toluene, dimethylbenzene.

4. preparation method according to claim 2, it is characterised in that: in step (1) or step (2), the inorganic salts are molten Liquid is saturated sodium carbonate solution or saturated sodium bicarbonate solution.

5. preparation method according to claim 2, it is characterised in that: in step (2), the solvent B is toluene, N, N- bis- At least one of methylformamide, dimethylbenzene.

6. preparation method according to claim 2, which is characterized in that in step (2), the end-capping reagent is two silicon of hexamethyl One of amine alkane, triphenyl oxosilane.