Polyvinyl perfluoropolyether fluorosilicone oil and preparation method thereof

Abstract

The invention belongs to the technical field of perfluoropolyether fluorosilicone oil preparation, and particularly relates to polyvinyl perfluoropolyether fluorosilicone oil and a preparation method thereof. The preparation method comprises the following steps: firstly, carrying out ring-opening reaction on tetramethyl tetravinyl cyclotetrasiloxane and cyclosiloxane to prepare polyvinyl polysiloxane, then carrying out reaction on the polyvinyl polysiloxane and perfluoropolyether trimethoxy silane to prepare polyvinyl perfluoropolyether fluorosilicone oil; the modified catalyst, which is prepared by carrying out a reaction on 1, 2, 5-g] isoquinoline and 2-iodopropane to prepare modified organic alkali and then carrying out a reaction on the modified organic alkali, tris (pentafluorophenyl) boron and mercaptan, has relatively high reaction activity, and avoids the difficulty in impurity removal by using a plurality of catalysts; the perfluoropolyether trimethoxy silane, which is prepared by reacting perfluoropolyether alcohol with allyl chloroformate and then carrying out addition with trimethoxy silane, has excellent mechanical properties. The preparation process is relatively simple, addition and use of a fluorine-containing solvent in the reaction process are reduced, and the prepared product contains more vinyl functional groups and has higher crosslinking degree and corrosion resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of perfluoropolyether fluorosilicone oil preparation, and specifically relates to polyvinyl perfluoropolyether fluorosilicone oil and a preparation method thereof. Background Art

[0002] Fluorosilicone oil refers to a type of silicone oil that contains fluorine-containing groups in the side groups of the polysiloxane chain. Introducing fluorine-containing groups into silicone polymers can reduce surface energy and improve solvent resistance, weather resistance and wear resistance. Perfluoropolyether is a high molecular polymer prepared from perfluorinated monomers. Compared with conventional fluorocarbon materials, the ether bond structure of perfluoropolyether has better biodegradability and lower toxicity than the carbon-carbon structure due to the introduction of oxygen elements.

[0003] The Chinese invention patent with publication number CN106336514B discloses a polyvinyl perfluoropolyether fluorosilicone oil and a preparation method thereof. The polyvinyl perfluoropolyether fluorosilicone oil is prepared with aminosilane coupling agent, tetramethyltetravinylcyclotetrasiloxane, hexamethyldisiloxane and perfluoropolyether compounds as main raw materials. The polyvinyl perfluoropolyether fluorosilicone oil of the invention has a high vinyl functionality and can significantly improve the mechanical strength and acid corrosion resistance of rubber when used to prepare rubber materials. However, the prior art does not further improve the raw material composition compounding and catalyst types of perfluoropolyether fluorosilicone oil, so as to improve the mechanical properties and corrosion resistance of rubber products after application. Summary of the invention

[0004] The object of the present invention is to provide a polyvinyl perfluoropolyether fluorosilicone oil and a preparation method thereof, so as to solve the technical problem that the prior art has not further improved the raw material composition compounding of the perfluoropolyether fluorosilicone oil and the catalyst types so as to improve the mechanical properties and corrosion resistance of the rubber products after being applied thereto.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing polyvinyl perfluoropolyether fluorosilicone oil comprises the following steps:

[0007] S1. Add tetramethyltetravinylcyclotetrasiloxane and cyclosiloxane into a reaction kettle, add n-hexane, introduce nitrogen to replace the air three times, add the modified catalyst dropwise under stirring, and complete the addition within 30 to 40 minutes. After the addition is completed, react at 70 to 90° C. for 2 to 6 hours;

[0008] S2, adding a capping agent to the reaction system of S1 for capping treatment, cooling the reaction solution and allowing it to stand for stratification, collecting the oil layer, washing it with water until it is neutral, and then distilling it under reduced pressure to obtain polyvinyl polysiloxane;

[0009] S3, adding polyvinyl polysiloxane and perfluoropolyether trimethoxysilane into a reaction kettle, adding a modified catalyst under stirring, and reacting at 70-90° C. for 5-8 hours;

[0010] After the reaction system of S4 and S3 is cooled to room temperature, methanol and trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0011] Preferably, the cyclosiloxane in S1 is one or more combinations of octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane and trimethylcyclotrisiloxane.

[0012] Preferably, the mass ratio of tetramethyltetravinylcyclotetrasiloxane, n-hexane, cyclosiloxane and modified catalyst in S1 is 1-2: 5-7: 6-8: 0.2-0.5.

[0013] Preferably, the capping agent in S2 is one or more combinations of ethanol, methanol and deionized water.

[0014] Preferably, the amount of the end-capping agent added in S2 is 80-90 wt % of the total amount of tetramethyltetravinylcyclotetrasiloxane and cyclosiloxane added in S1.

[0015] Preferably, the mass ratio of polyvinyl polysiloxane, modified catalyst and perfluoropolyether trimethoxysilane in S3 is 5-8:0.2-0.5:1-3.

[0016] Preferably, the method for preparing the modified catalyst comprises the following steps:

[0017] S11, adding tri(pentafluorophenyl)borane to ethyl acetate, adding modified organic base and thiol under stirring, and reacting at room temperature for 12 to 16 hours;

[0018] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane for 2 to 3 times, and drying to obtain a modified catalyst.

[0019] Preferably, the mass ratio of tri(pentafluorophenyl)borane, ethyl acetate, modified organic base and thiol in S11 is 2-3:60-80:10-15:5-7.

[0020] Preferably, the method for preparing the modified organic base comprises the following steps:

[0021] S21, adding 1H-imidazo[4,5-g]isoquinoline and a base catalyst into toluene, heating to 70-80° C. to react for 1-2 hours, and cooling the system to room temperature after the reaction is completed;

[0022] S22, add 2-iodopropane dropwise to the system within 1 to 2 hours, heat to 95 to 100°C, reflux for 36 to 48 hours, add deionized water and dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0023] S23. Add iodine salt to toluene, add toluene solution of potassium hexamethyldisilazide and react at room temperature for 12 to 18 hours. After the reaction is completed, filter and collect the solid, extract with n-hexane, and recrystallize at -10 to 0°C to obtain a modified organic base.

[0024] Preferably, the synthetic reaction principle involved in the preparation process of the modified organic base is as follows:

[0025]

[0026] Preferably, the alkaline catalyst in S21 is one or more combinations of potassium carbonate, potassium hydroxide and sodium hydroxide.

[0027] Preferably, the mass ratio of 1H-imidazo[4,5-g]isoquinoline, base catalyst, toluene and 2-iodopropane in S21 and S22 is 4-6:2-3:15-30:20-23.

[0028] Preferably, the mass ratio of iodine salt to potassium hexamethyldisilazide in S23 is 2:1 to 1.2.

[0029] Preferably, the preparation method of the perfluoropolyether trimethoxysilane comprises the following steps:

[0030] S31, adding perfluoropolyether alcohol to cyclohexane, adding sodium hydride under stirring, adding allyl chloroformate dropwise within 1 to 2 hours, raising the temperature to 55 to 65° C. and reacting for 12 to 20 hours to obtain a mixed solution;

[0031] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water 2 to 3 times, perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0032] S33. Add perfluoropolyether allyl ether and chloroplatinic acid into cyclohexane, raise the temperature to 55-65°C, then add trimethoxysilane dropwise, and complete the addition within 1-2 hours. After keeping the temperature at 55-65°C for 3-4 hours, raise the temperature to 70-80°C and react for 12-16 hours. Low-pressure distillation is performed to obtain perfluoropolyether trimethoxysilane.

[0033] Preferably, the synthesis reaction principle involved in the preparation process of the perfluoropolyether trimethoxysilane is as follows:

[0034]

[0035] Preferably, the mass ratio of perfluoropolyether alcohol, cyclohexane, sodium hydride and allyl chloroformate in S31 is 1-5:5-10:0.1-0.3:0.1-0.3.

[0036] Preferably, the mass ratio of perfluoropolyether propyl formate, chloroplatinic acid, cyclohexane and trimethoxysilane in S33 is 2:0.1-0.3:1-5:0.5-0.6.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. The present invention optimizes the preparation method of polyvinyl perfluoropolyether fluorosilicone oil on the basis of the prior art. First, tetramethyltetravinylcyclotetrasiloxane and cyclosiloxane are subjected to a ring-opening reaction to prepare polyvinyl polysiloxane, which is then reacted with perfluoropolyether trimethoxysilane to obtain polyvinyl perfluoropolyether fluorosilicone oil. The reaction process is relatively simple, easy to operate and control, and reduces the addition and use of fluorine-containing solvents during the reaction process. The obtained polyvinyl perfluoropolyether fluorosilicone oil contains more vinyl functional groups, has a higher degree of crosslinking and corrosion resistance.

[0039] 2. The present invention prepares a Lewis acid-base modified catalyst by reacting tri(pentafluorophenyl)boron with a modified organic base and a thiol. The reaction operation is relatively simple and the energy consumption required for the reaction is relatively small. Tri(pentafluorophenyl)boron and the modified organic base have a large steric hindrance and cannot approach each other without the existence of an interaction force. Therefore, the modified catalyst prepared by tri(pentafluorophenyl)boron with a modified organic base and a thiol can still maintain a high reaction activity to catalyze the ring-opening reaction and the addition reaction, thereby avoiding the problem of difficulty in removing impurities when using multiple catalysts.

[0040] 3. The modified organic base prepared by the reaction of 1H-imidazo[4,5-g]isoquinoline with 2-iodopropane has a large steric hindrance and a lone pair of electrons. The catalytic activity of the catalyst formed by the reaction with tri(pentafluorophenyl)borane is higher than that of the ring-opening reaction and addition reaction catalyzed by tri(pentafluorophenyl)borane alone.

[0041] 4. In the present invention, perfluoropolyether propyl formate is prepared by reacting perfluoropolyether alcohol with allyl chloroformate, and then the perfluoropolyether trimethoxysilane is prepared by addition reaction with trimethoxysilane. The utilization rate of the raw materials is high, and waste and the generation of by-products are reduced. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Embodiment 1, a method for preparing a polyvinyl perfluoropolyether fluorosilicone oil of this embodiment comprises the following steps:

[0044] S1. Add 20 g of tetramethyltetravinylcyclotetrasiloxane and 120 g of octamethylcyclotetrasiloxane into a reaction kettle, add 100 g of n-hexane, introduce nitrogen to replace the air three times, and drop 5 g of the modified catalyst under stirring within 40 min. After the dropwise addition is completed, react at 80 ° C for 4 h;

[0045] S2, adding 112g of 30wt% ethanol aqueous solution to the reaction system of S1 for end-capping treatment, cooling the reaction solution to room temperature, standing for stratification, collecting the oil layer, washing with water until neutral, and distilling under reduced pressure to obtain polyvinyl polysiloxane;

[0046] S3, adding 100 g of polyvinyl polysiloxane and 30 g of perfluoropolyether trimethoxysilane into a reaction kettle, adding 5 g of a modified catalyst while stirring, and reacting at 80° C. for 6 h;

[0047] After the reaction system of S4 and S3 is cooled to room temperature, 150 ml of methanol and 150 ml of trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0048] The preparation method of the modified catalyst of this embodiment comprises the following steps:

[0049] S11, add 3.3 g of tris(pentafluorophenyl)borane to 70 g of ethyl acetate, add 12 g of modified organic base and 6.2 g of mercaptan under stirring, and react at room temperature for 12 h;

[0050] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane for 3 times, and drying to obtain a modified catalyst.

[0051] The method for preparing the modified organic base of this embodiment comprises the following steps:

[0052] S21, adding 5.1 g of 1H-imidazo[4,5-g]isoquinoline and 2.7 g of potassium carbonate to 30 g of toluene, heating to 70° C. and reacting for 2 h, and cooling the system to room temperature after the reaction;

[0053] S22, add 25.5g of 2-iodopropane to the system dropwise within 2h, heat to 100°C and reflux for 48h, add 30ml of deionized water and 30ml of dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0054] S23. Add 20 g of iodine salt to 20 ml of toluene, add 30 ml of toluene solution containing 10 g of potassium hexamethyldisilazide, and react at room temperature for 18 hours. After the reaction, filter and collect the solid, extract with n-hexane, and recrystallize at -10°C to obtain a modified organic base.

[0055] The preparation method of perfluoropolyether trimethoxysilane of this embodiment comprises the following steps:

[0056] S31, add 3 g of perfluoropolyether alcohol with a number average molecular weight of about 3000 to 10 g of cyclohexane, add 0.2 g of sodium hydride under stirring, add 0.18 g of allyl chloroformate dropwise within 2 h, heat to 60 ° C and react for 18 h to obtain a mixed solution;

[0057] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water twice, 10 ml of perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0058] S33. Add 2 g of perfluoropolyether propyl formate and 0.1 g of chloroplatinic acid into cyclohexane, heat to 60°C and then add 0.5 g of trimethoxysilane dropwise within 2 h. Keep the temperature at 60°C for 4 h, heat to 75°C and react for 12 h. Distill under low pressure to obtain perfluoropolyether trimethoxysilane.

[0059] Embodiment 2, a method for preparing a polyvinyl perfluoropolyether fluorosilicone oil of this embodiment comprises the following steps:

[0060] S1. Add 40 g of tetramethyltetravinylcyclotetrasiloxane and 120 g of hexamethylcyclotrisiloxane into a reaction kettle, add 140 g of n-hexane, introduce nitrogen to replace the air three times, and add 6 g of modified catalyst dropwise under stirring within 30 min. After the addition is completed, react at 75 ° C for 6 h;

[0061] S2, adding 130g of 40wt% ethanol aqueous solution to the reaction system of S1 for end-capping treatment, cooling the reaction solution to room temperature, standing for stratification, collecting the oil layer, washing with water until neutral, and distilling under reduced pressure to obtain polyvinyl polysiloxane;

[0062] S3, adding 100 g of polyvinyl polysiloxane and 40 g of perfluoropolyether trimethoxysilane into a reaction kettle, adding 2.5 g of a modified catalyst while stirring, and reacting at 90° C. for 8 h;

[0063] After the reaction system of S4 and S3 is cooled to room temperature, 200 ml of methanol and 200 ml of trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0064] The preparation method of the modified catalyst of this embodiment comprises the following steps:

[0065] S11, add 6.6 g of tris(pentafluorophenyl)borane to 80 g of ethyl acetate, add 14.9 g of modified organic base and 6.8 g of mercaptan under stirring, and react at room temperature for 18 h;

[0066] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane twice, and drying to obtain a modified catalyst.

[0067] The method for preparing the modified organic base of this embodiment comprises the following steps:

[0068] S21, adding 4.2 g of 1H-imidazo[4,5-g]isoquinoline and 2.7 g of potassium hydroxide to 35 g of toluene, heating to 75° C. to react for 2 h, and cooling the system to room temperature after the reaction;

[0069] S22, add 27.7g of 2-iodopropane to the system dropwise within 2h, heat to 95°C and reflux for 48h, add 30ml of deionized water and 30ml of dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0070] S23. Add 20 g of iodine salt to 20 ml of toluene, add 30 ml of toluene solution containing 10 g of potassium hexamethyldisilazide, and react at room temperature for 12 hours. After the reaction, filter and collect the solid, extract with n-hexane, and recrystallize at -5°C to obtain a modified organic base.

[0071] The preparation method of perfluoropolyether trimethoxysilane of this embodiment comprises the following steps:

[0072] S31, add 4 g of perfluoropolyether alcohol with a number average molecular weight of about 4000 to 10 g of cyclohexane, add 0.3 g of sodium hydride under stirring, add 0.24 g of allyl chloroformate dropwise within 2 h, heat to 65 ° C and react for 20 h to obtain a mixed solution;

[0073] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water three times, 15 ml of perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0074] S33. Add 2 g of perfluoropolyether propyl formate and 0.2 g of chloroplatinic acid into cyclohexane, heat to 55°C and then add 0.55 g of trimethoxysilane dropwise within 2 h. Keep the temperature at 55°C for 3 h, heat to 80°C and react for 16 h. Distill under low pressure to obtain perfluoropolyether trimethoxysilane.

[0075] Embodiment 3, a method for preparing a polyvinyl perfluoropolyether fluorosilicone oil of this embodiment comprises the following steps:

[0076] S1. Add 30 g of tetramethyltetravinylcyclotetrasiloxane and 180 g of trimethylcyclotrisiloxane into a reaction kettle, add 150 g of n-hexane, introduce nitrogen to replace the air three times, and add 10 g of modified catalyst dropwise under stirring within 30 min. After the addition is completed, react at 70 ° C for 8 h;

[0077] S2, adding 185g of 50wt% methanol aqueous solution to the reaction system of S1 for end-capping treatment, cooling the reaction solution to room temperature, standing for stratification, collecting the oil layer, washing with water until neutral, and distilling under reduced pressure to obtain polyvinyl polysiloxane;

[0078] S3, adding 120g of polyvinyl polysiloxane and 15g of perfluoropolyether trimethoxysilane into a reaction kettle, adding 3g of modified catalyst under stirring, and reacting at 80°C for 8h;

[0079] After the reaction system of S4 and S3 is cooled to room temperature, 150 ml of methanol and 150 ml of trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0080] The preparation method of the modified catalyst of this embodiment comprises the following steps:

[0081] S11, add 2.6 g of tris(pentafluorophenyl)borane to 60 g of ethyl acetate, add 15 g of modified organic base and 5.2 g of mercaptan under stirring, and react at room temperature for 14 h;

[0082] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane for 3 times, and drying to obtain a modified catalyst.

[0083] The method for preparing the modified organic base of this embodiment comprises the following steps:

[0084] S21, adding 5.1 g of 1H-imidazo[4,5-g]isoquinoline and 2 g of potassium carbonate to 25 g of toluene, heating to 70° C. for reaction for 1 h, and cooling the system to room temperature after the reaction;

[0085] S22, add 15.3 g of 2-iodopropane to the system, complete the addition within 2 h, heat to 95 ° C and reflux for 42 h, add 30 ml of deionized water and 30 ml of dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0086] S23. Add 20 g of iodine salt to 20 ml of toluene, add 30 ml of toluene solution containing 12 g of potassium hexamethyldisilazide, and react at room temperature for 18 hours. After the reaction, filter and collect the solid, extract with n-hexane, and recrystallize at 0°C to obtain a modified organic base.

[0087] The preparation method of perfluoropolyether trimethoxysilane of this embodiment comprises the following steps:

[0088] S31, add 3.5g of perfluoropolyether alcohol with a number average molecular weight of about 3500 to 10g of cyclohexane, add 0.2g of sodium hydride under stirring, add 0.12g of allyl chloroformate dropwise within 2h, heat to 60°C and react for 20h to obtain a mixed solution;

[0089] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water twice, 10 ml of perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0090] S33. Add 2 g of perfluoropolyether propyl formate and 0.1 g of chloroplatinic acid into cyclohexane, heat to 60°C and then add 0.5 g of trimethoxysilane dropwise within 2 h. Keep the temperature at 60°C for 4 h, heat to 80°C and react for 16 h. Distill under low pressure to obtain perfluoropolyether trimethoxysilane.

[0091] Embodiment 4, a method for preparing a polyvinyl perfluoropolyether fluorosilicone oil of this embodiment comprises the following steps:

[0092] S1, 20g of tetramethyltetravinylcyclotetrasiloxane, 120g of octamethylcyclotetrasiloxane and 20g of hexamethylcyclotrisiloxane were added to a reaction kettle, 120g of n-hexane was added, nitrogen was introduced to replace the air three times, 10g of modified catalyst was added dropwise under stirring, the addition was completed within 30min, and the reaction was carried out at 90°C for 2h after the addition was completed;

[0093] S2, adding 136g of 40wt% ethanol aqueous solution to the reaction system of S1 for end-capping treatment, cooling the reaction solution to room temperature, standing for stratification, collecting the oil layer, washing with water until neutral, and distilling under reduced pressure to obtain polyvinyl polysiloxane;

[0094] S3, adding 100 g of polyvinyl polysiloxane and 50 g of perfluoropolyether trimethoxysilane into a reaction kettle, adding 8 g of a modified catalyst under stirring, and reacting at 80° C. for 8 h;

[0095] After the reaction system of S4 and S3 is cooled to room temperature, 200 ml of methanol and 200 ml of trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0096] The preparation method of the modified catalyst of this embodiment comprises the following steps:

[0097] S11, add 3 g of tris(pentafluorophenyl)borane to 75 g of ethyl acetate, add 10 g of modified organic base and 5 g of mercaptan under stirring, and react at room temperature for 12 h;

[0098] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane for 3 times, and drying to obtain a modified catalyst.

[0099] The method for preparing the modified organic base of this embodiment comprises the following steps:

[0100] S21, adding 5.9 g of 1H-imidazo[4,5-g]isoquinoline and 3 g of potassium carbonate to 40 g of toluene, heating to 80° C. for reaction for 2 h, and cooling the system to room temperature after the reaction;

[0101] S22, add 23.6g of 2-iodopropane to the system dropwise within 2h, heat to 100°C and reflux for 36h, add 30ml of deionized water and 30ml of dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0102] S23. Add 20 g of iodine salt to 20 ml of toluene, add 30 ml of toluene solution containing 11 g of potassium hexamethyldisilazide, and react at room temperature for 12 hours. After the reaction, filter and collect the solid, extract with n-hexane, and recrystallize at -10°C to obtain a modified organic base.

[0103] The preparation method of perfluoropolyether trimethoxysilane of this embodiment comprises the following steps:

[0104] S31, add 2.5g of perfluoropolyether alcohol with a number average molecular weight of about 2500 to 5g of cyclohexane, add 0.3g of sodium hydride under stirring, add 0.12g of allyl chloroformate dropwise within 2h, heat to 60°C and react for 18h to obtain a mixed solution;

[0105] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water twice, 10 ml of perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0106] S33. Add 2 g of perfluoropolyether propyl formate and 0.3 g of chloroplatinic acid into cyclohexane, heat to 60°C and then add 0.5 g of trimethoxysilane dropwise within 1 hour. Keep the temperature at 60°C for 4 hours, heat to 75°C and react for 14 hours. Distill under low pressure to obtain perfluoropolyether trimethoxysilane.

[0107] Embodiment 5, a method for preparing a polyvinyl perfluoropolyether fluorosilicone oil of this embodiment comprises the following steps:

[0108] S1. Add 20 g of tetramethyltetravinylcyclotetrasiloxane and 160 g of octamethylcyclotetrasiloxane into a reaction kettle, add 140 g of n-hexane, introduce nitrogen to replace the air three times, and add 9 g of modified catalyst dropwise under stirring within 35 min. After the addition is completed, react at 90 ° C for 2 h;

[0109] S2, adding 145g of 50wt% ethanol aqueous solution to the reaction system of S1 for end-capping treatment, cooling the reaction solution to room temperature, standing for stratification, collecting the oil layer, washing with water until neutral, and distilling under reduced pressure to obtain polyvinyl polysiloxane;

[0110] S3, adding 100 g of polyvinyl polysiloxane and 60 g of perfluoropolyether trimethoxysilane into a reaction kettle, adding 4 g of a modified catalyst while stirring, and reacting at 90° C. for 5 h;

[0111] After the reaction system of S4 and S3 is cooled to room temperature, 150 ml of methanol and 150 ml of trifluorotoluene are added for extraction, the system is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

[0112] The preparation method of the modified catalyst of this embodiment comprises the following steps:

[0113] S11, add 3.3 g of tris(pentafluorophenyl)borane to 70 g of ethyl acetate, add 12 g of modified organic base and 6.2 g of mercaptan under stirring, and react at room temperature for 12 h;

[0114] S12, filtering the reaction system to remove ethyl acetate, washing with n-hexane for 3 times, and drying to obtain a modified catalyst.

[0115] The method for preparing the modified organic base of this embodiment comprises the following steps:

[0116] S21, adding 5.9 g of 1H-imidazo[4,5-g]isoquinoline and 2 g of sodium carbonate to 30 g of toluene, heating to 80° C. for reaction for 1 h, and cooling the system to room temperature after the reaction;

[0117] S22, add 17.7 g of 2-iodopropane to the system, complete the addition within 1 hour, heat to 100°C and reflux for 36 hours, add 30 ml of deionized water and 30 ml of dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt;

[0118] S23. Add 20 g of iodine salt to 20 ml of toluene, add 30 ml of toluene solution containing 12 g of potassium hexamethyldisilazide, and react at room temperature for 18 hours. After the reaction, filter and collect the solid, extract with n-hexane, and recrystallize at -10°C to obtain a modified organic base.

[0119] The preparation method of perfluoropolyether trimethoxysilane of this embodiment comprises the following steps:

[0120] S31, add 1.5g of perfluoropolyether alcohol with a number average molecular weight of about 3000 to 5g of cyclohexane, add 0.1g of sodium hydride under stirring, add 0.12g of allyl chloroformate dropwise within 2h, heat to 65°C and react for 12h to obtain a mixed solution;

[0121] S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water twice, 10 ml of perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate;

[0122] S33. Add 2 g of perfluoropolyether propyl formate and 0.1 g of chloroplatinic acid into cyclohexane, raise the temperature to 55°C, then add 0.6 g of trimethoxysilane dropwise within 2 h. Keep the temperature at 55°C for 4 h, raise the temperature to 75°C, react for 16 h, and obtain perfluoropolyether trimethoxysilane by low-pressure distillation.

[0123] Comparative Example 1: The difference between this comparative example and Example 1 is that the modified catalyst is changed to tris(pentafluorophenyl)boron.

[0124] Comparative Example 2: This comparative example differs from Example 1 in that 1H-imidazo[4,5-g]isoquinoline in the preparation method of the modified organic base is replaced by pyrido[2,3-b]pyrazine.

[0125] Comparative Example 3: The difference between this comparative example and Example 1 is that perfluoropolyether alcohol is directly reacted with trimethoxysilane to prepare perfluoropolyether trimethoxysilane.

[0126] Performance Testing

[0127] Modified rubber preparation:

[0128] 1. Add methyl vinyl silicone rubber and carbon black into an open mill and mix for 20 minutes. Add dicumyl peroxide vulcanizing agent and vulcanize at 150°C for 30 minutes. Each rubber contains 100g methyl vinyl silicone rubber, 40g carbon black and 15g dicumyl peroxide vulcanizing agent.

[0129] 2. Take 2 g of the polyvinyl perfluoropolyether fluorosilicone oil prepared in each embodiment and comparative example and add them to methyl vinyl silicone rubber, pass them through an open mill 10 times, cool them to room temperature and let them stand for 48 hours, perform secondary vulcanization at 100°C for 2 hours, and cool them to room temperature to obtain modified methyl vinyl silicone rubber.

[0130] Mechanical properties test

[0131] According to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", the tensile strength, elongation at break and hardness of modified methyl vinyl silicone rubber were measured. The test results are shown in Table 1 below:

[0132] Table 1

[0133]

[0134]

[0135] From the data shown in Table 1, it can be seen that the tensile strength of the modified methyl vinyl silicone rubber of Examples 1 to 5 is between 9.6 and 10.4 MPa, and the elongation at break is between 317 and 324%, indicating that the polyvinyl perfluoropolyether fluorosilicone oil prepared in each example has excellent mechanical properties; the hardness of the modified methyl vinyl silicone rubber of Examples 1 to 5 is between 56 and 59 Shores, indicating that the polyvinyl perfluoropolyether fluorosilicone oil prepared in each example has the performance of enhancing the hardness of methyl vinyl silicone rubber. In Comparative Example 3, perfluoropolyether alcohol is directly reacted with trimethoxysilane to prepare perfluoropolyether trimethoxysilane, resulting in a shorter chain length, weaker hardness and crosslinking degree than each example, and the mechanical properties and hardness of the modified methyl vinyl silicone rubber are both less than the values ​​of the modified methyl vinyl silicone rubber in each example.

[0136] Corrosion resistance test

[0137] The modified methyl vinyl silicone rubber prepared in each embodiment and comparative example was immersed in 3.5wt% dilute hydrochloric acid for 72 hours, and the tensile strength, elongation at break and hardness of the modified methyl vinyl silicone rubber were measured after 72 hours. The test results are shown in Table 2 below:

[0138] Table 2

[0139]

[0140]

[0141] From the data shown in Table 1, it can be seen that the modified methyl vinyl silicone rubber prepared in Examples 1 to 5 has a tensile strength decrease of 0.4 to 0.5 MPa and a break elongation decrease of 2 to 3% after being immersed in 3.5wt% dilute hydrochloric acid for 72 hours, indicating that the polyvinyl perfluoropolyether fluorosilicone oil of the present invention has excellent corrosion resistance.

[0142] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0143] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing polyvinyl perfluoropolyether fluorosilicone oil, characterized in that: The steps include: S1. Add tetramethyltetravinylcyclotetrasiloxane and cyclosiloxane into a reaction kettle, add n-hexane, introduce nitrogen to replace the air three times, add the modified catalyst dropwise under stirring, and complete the addition within 30 to 40 minutes. After the addition is completed, react at 70 to 90° C. for 2 to 6 hours; S2, adding a capping agent to the reaction system of S1 for capping treatment, cooling the reaction solution and allowing it to stand for stratification, collecting the oil layer, washing it with water until it is neutral, and then distilling it under reduced pressure to obtain polyvinyl polysiloxane; S3, adding polyvinyl polysiloxane and perfluoropolyether trimethoxysilane into a reaction kettle, adding a modified catalyst under stirring, and reacting at 70-90° C. for 5-8 hours; After the reaction system of S4 and S3 is cooled to room temperature, a mixed solvent of methanol and trifluorotoluene is added for extraction, the mixture is allowed to stand for stratification, the lower layer of liquid is collected, and the polyvinyl perfluoropolyether fluorosilicone oil is obtained by vacuum distillation.

2. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 1, characterized in that: The cyclosiloxane in S1 is one or more combinations of octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane and trimethylcyclotrisiloxane, and the mass ratio of tetramethyltetravinylcyclotetrasiloxane, n-hexane, cyclosiloxane and modified catalyst is 1-2:5-7:6-8:0.2-0.

5.

3. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 1, characterized in that: The end-capping agent in S2 is one or more combinations of ethanol, methanol and deionized water, and the amount of the end-capping agent added is 80-90% of the total added mass of tetramethyltetravinylcyclotetrasiloxane and cyclosiloxane in S1; the mass ratio of polyvinyl polysiloxane, modified catalyst and perfluoropolyether trimethoxysilane in S3 is 5-8:0.2-0.5:1-3.

4. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 1, characterized in that: The preparation method of the modified catalyst comprises the following steps: S11, adding tri(pentafluorophenyl)borane to ethyl acetate, adding modified organic base and thiol under stirring, and reacting at room temperature for 12 to 16 hours; S12, filtering the reaction system of S11 to remove ethyl acetate, washing with n-hexane for 2 to 3 times, and drying to obtain a modified catalyst.

5. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 4, characterized in that: The mass ratio of tri(pentafluorophenyl)borane, ethyl acetate, modified organic base and thiol in S11 is 2-3:60-80:10-15:5-7.

6. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 4, characterized in that: The preparation method of the modified organic base comprises the following steps: S21, adding 1H-imidazo[4,5-g]isoquinoline and a base catalyst into toluene, heating to 70-80° C. to react for 1-2 hours, and cooling the system to room temperature after the reaction is completed; S22, add 2-iodopropane to the system of S21, and complete the addition within 1 to 2 hours, raise the temperature to 95 to 100°C, reflux for 36 to 48 hours, add deionized water and dichloromethane for extraction after the reaction, and vacuum dry to obtain iodized salt; S23. Add iodine salt to toluene, add toluene solution of potassium hexamethyldisilazide, react at room temperature for 12 to 18 hours, filter and collect solid after the reaction, extract with n-hexane, and recrystallize at -10 to 0°C to obtain a modified organic base.

7. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 6, characterized in that: The alkaline catalyst in S21 is one or more combinations of potassium carbonate, potassium hydroxide and sodium hydroxide; the mass ratio of 1H-imidazo[4,5-g]isoquinoline, alkaline catalyst, toluene and 2-iodopropane is 4-6:2-3:15-30:20-23; the mass ratio of iodine salt and potassium hexamethyldisilazide in S23 is 2:1-1.

2.

8. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 1, characterized in that: The preparation method of the perfluoropolyether trimethoxysilane comprises the following steps: S31, adding perfluoropolyether alcohol to cyclohexane, adding sodium hydride under stirring, adding allyl chloroformate dropwise within 1 to 2 hours, raising the temperature to 55 to 65° C. and reacting for 12 to 20 hours to obtain a mixed solution; S32, after the reaction is completed, the mixed solution is cooled to room temperature, 10 wt % hydrochloric acid is added to neutralize it to neutrality, and then washed with water 2 to 3 times, perfluorocyclic ether is added for extraction, and low-pressure fractionation is performed to obtain perfluoropolyether propyl formate; S33. Add propyl perfluoropolyether formate and chloroplatinic acid into cyclohexane, raise the temperature to 55-65°C, then add trimethoxysilane dropwise, and complete the addition within 1-2 hours. After keeping the temperature at 55-65°C for 3-4 hours, raise the temperature to 70-80°C and react for 12-16 hours. Low-pressure distillation is performed to obtain perfluoropolyether trimethoxysilane.

9. The method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to claim 8, characterized in that: The mass ratio of perfluoropolyether alcohol, cyclohexane, sodium hydride and allyl chloroformate in S31 is 1-5: 5-10: 0.1-0.3: 0.1-0.3; the mass ratio of perfluoropolyether propyl formate, chloroplatinic acid, cyclohexane and trimethoxysilane in S33 is 2: 0.1-0.3: 1-5: 0.5-0.

6.

10. A polyvinyl perfluoropolyether fluorosilicone oil prepared according to the method for preparing a polyvinyl perfluoropolyether fluorosilicone oil according to any one of claims 1 to 9.

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