阅读说明：本技术 一种苯基氟硅氧烷聚合物及制备方法 (Phenyl fluorosilicone polymer and preparation method thereof ) 是由 田志钢 侯志伟 杜辉 于鹏飞 林峰 夏子祥 谢会庆 于佳平 于 2020-07-09 设计创作，主要内容包括：本发明涉及一种苯基氟硅氧烷聚合物及制备方法,首先将三氟丙基甲基二氯硅烷和甲基苯基二氯硅烷通过共水解后在碱性催化剂作用下裂解制备式Ⅱ化合物,然后将式Ⅱ化合物与甲基三氟丙基环三硅氧烷(D<Sub>3</Sub>F)通过碱性催化剂非平衡共聚制备苯基氟硅氧烷聚合物。本发明的式Ⅱ化合物与D<Sub>3</Sub>F聚合速率一致,可实现聚合物中甲基苯基硅氧链节在甲基三氟丙基硅氧链节中的均匀分布,无需复杂的聚合及后处理工艺即可得到收率高、耐热性好、不同粘度或不同分子量的苯基氟硅氧烷聚合物。<Image he="517" wi="633" file="DDA0002576957500000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention relates to a phenyl fluorosilicone polymer and a preparation method thereof, which comprises the steps of firstly preparing a compound shown in a formula II by cracking trifluoropropyl methyl dichlorosilane and methyl phenyl dichlorosilane under the action of an alkaline catalyst after cohydrolysis, and then preparing the compound shown in the formula II and methyl trifluoro propyl cyclotrisiloxane (D) 3 F) Phenyl fluorosilicone polymer is prepared through non-equilibrium copolymerization of alkaline catalyst. Compounds of the formula II and D according to the invention 3 The polymerization rate of F is consistent, the even distribution of methyl phenyl siloxane chain segments in the polymer in methyl trifluoro propyl siloxane chain segments can be realized, and the phenyl fluoro siloxane polymer with high yield, good heat resistance, different viscosity or different molecular weight can be obtained without complex polymerization and post-treatment processes.)

1. A phenyl fluorosilicone polymer, wherein the polymer has a structure shown in formula I:

in the formula I, x is greater than 0, and y is greater than 0; and the phenyl groups can be uniformly distributed on the molecular chain of the phenyl fluorosilicone polymer no matter how much the phenyl groups in the phenyl fluorosilicone polymer are.

2. The phenylfluorosilicone polymer according to claim 1, wherein the phenylfluorosilicone polymer is prepared from methyltrifluoropropylcyclotrisiloxane (D)₃F) And the compound of the formula II is prepared by non-equilibrium copolymerization;

3. the phenylfluorosilicone polymer according to claim 3, wherein the preparation method of the compound of formula II comprises the steps of:

mixing trifluoropropylmethyldichlorosilane and methylphenyldichlorosilane, dropwise adding the mixture into water for hydrolysis, continuously maintaining the reaction temperature after the dropwise adding is finished, stirring to ensure that the hydrolysis reaction is complete, washing the hydrolysate to be neutral, then adding an alkaline catalyst and a cracking assistant for cracking reaction, collecting fractions at 100-110 ℃, and finally rectifying to obtain the compound of the formula II.

4. The phenylfluorosilicone polymer according to claim 4, wherein the molar ratio of trifluoropropylmethyldichlorosilane to methylphenyldichlorosilane is 2:1 to 6: 1;

preferably, the mass ratio of the mixture of trifluoropropylmethyldichlorosilane and methylphenyldichlorosilane to water is 1: 1-1: 3.

5. The phenylfluorosilicone polymer according to claim 4, wherein the reaction temperature of the hydrolysis reaction is 40 to 80 ℃;

preferably, the alkaline catalyst is NaOH, and the using amount of the alkaline catalyst is 1-3% of the mass of the hydrolysate;

preferably, the cracking assistant is one or a mixture of more of benzophenone, diphenyl sulfoxide and diphenyl sulfone, and the addition amount is 10-20% of the mass of the hydrolysate;

preferably, the cracking temperature is 170-220 ℃;

preferably, the rectification temperature is 110-120 ℃, and the rectification is carried out under the pressure of 260-270 Pa to obtain a compound product shown in the formula II.

6. The method for preparing phenyl fluorosilicone polymer according to claim 1, comprising the steps of:

will D₃And F and a compound shown in the formula II are mixed, vacuum dehydration is carried out, an alkaline catalyst, an end-capping agent and an auxiliary agent are added, heating polymerization is carried out for 1-3 h, acid glue is added for neutralization after polymerization is finished, and finally, the temperature is raised to 190 ℃ and low-boiling-point substances are removed in vacuum under the pressure of 266Pa, so that the phenyl fluorosilicone polymer is obtained.

7. The method for preparing phenyl fluorosilicone polymer according to claim 7, wherein the vacuum dehydration temperature is 50 to 60 ℃ and the pressure is 266 Pa.

8. The method for preparing phenylfluorosilicone polymer according to claim 7, wherein the polymerization reaction basic catalyst is LiOH, LiOH and D₃F prepared alkali glue, NaOH and D₃F, adding 10-40 ppm of alkali glue and the like prepared by F in terms of LiOH or NaOH;

preferably, the use of LiOH, LiOH and D₃The polymerization temperature of the alkali gel catalyst prepared by F is 150-170 ℃, and NaOH, NaOH and D are used₃F preparation of alkali gel catalysisThe polymerization temperature of the agent is 110-130 ℃.

9. The method for preparing phenyl fluorosilicone polymer according to claim 7, wherein the end capping agent is vinyl fluorosilicone oil, vinyl dimethylsilicone or trimethylsilicone, and the addition amount is D₃0.01-10% of the total mass of the compounds F and II;

preferably, the auxiliary agent is methyl vinyl cyclotrisiloxane, and the addition amount is D₃0.001-5% of the total mass of the compounds F and II.

Technical Field

The invention relates to a preparation method of an organic silicon polymer, in particular to a preparation method of a phenyl fluorosilicone polymer, belonging to the field of organic silicon.

Background

The fluorosilicone polymer is prepared by polymerization reaction of methyl trifluoro propyl cyclotrisiloxane, and has the characteristics of oil resistance and solvent resistance due to electronegativity and electron-withdrawing effect of fluorine atoms, so that the fluorosilicone polymer is widely applied to the oil-related sealing fields of aerospace, automobiles, machinery, chemical engineering and the like. Also, the heat resistance of the fluorosilicone polymer is lower than that of a general dimethylsiloxane polymer because the trifluoropropyl group attached to the silicon atom lowers the heat stability of the fluorosilicone polymer.

The phenyl group has oxidation resistance and thermal stability, so that the phenyl polysiloxane has better heat resistance than common polydimethylsiloxane, and the long-term use temperature can reach more than 300 ℃. In order to improve the heat resistance of fluorosilicone polymers, researchers began to consider incorporating phenyl groups into fluorosilicone polymers, such as proposed by Fiwassan et al, in "Synthesis and Properties of Fluorophenylpolysiloxane", p-trifluoromethylphenyltrifluoropropyl mixed ring body was prepared by a series of complex reactions, and then reacted with D₃F equilibrium copolymerization is used for preparing phenyl-containing fluorosilicone polymer, the heat resistance of the phenyl-containing fluorosilicone polymer is obviously improved, but the method is complex in process and not suitable for industrial production; wangshuai, Zhou Zhuan in the preparation of copolymer of methyltrifluoropropylsiloxane and methylphenylsiloxane (reference 1) proposed the use of KOH as a catalyst and D₃F. Methyl phenyl ring body and D₃ ^FViThe method is used for preparing phenyl-containing fluorosilicone raw rubber by equilibrium copolymerizationThe content of cyclic body is too high, the post-treatment process of solvent washing is needed, the preparation method is at the cost of yield loss, and the application requirement cannot be met; chinese patent document CN201910536793.1 (reference 2) discloses a preparation method and application of diphenyl cyclotrisiloxane, and mentions a structure of diphenyl methyl trifluoropropyl mixed cyclotrisiloxane, but due to strong electron withdrawing effect and large steric hindrance effect of diphenyl, diphenyl can be combined with D₃F is copolymerized in an unbalanced state, but the reactivity ratios are still different, in the presence of D in equimolar amounts₃When F is polymerized, D₃The polymerization activity of F is still higher than that of the phenyl ring, and uneven distribution of phenyl in the polymer is easily caused; chinese patent document CN03128909.6 discloses a fluorine-containing mixed cyclosiloxane, a preparation method and use thereof, mentioning a preparation method of a fluorine-containing mixed cyclic body, but the obtained mixture has no great practical significance for non-equilibrium copolymerization reaction, i.e. a phenyl fluorosilicone polymer with high yield cannot be obtained.

At present, the problems of uniform distribution of phenyl groups on a phenyl fluorosilicone polymer molecular chain, complex preparation process, low yield, incapability of industrial production and the like can not be solved in the prior art.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a phenyl fluorosilicone polymer and a preparation method thereof, which comprises the steps of firstly preparing methyl phenyl methyl trifluoro propyl mixed cyclotrisiloxane, and mixing the methyl phenyl methyl trifluoro propyl mixed cyclotrisiloxane and D₃The structure of the F is closer, the F is mutually soluble, the polymerization rate is basically consistent, and then the phenyl fluorosilicone polymer which has uniform phenyl distribution and high yield and is convenient for industrial production is prepared by non-equilibrium polymerization.

The technical scheme of the invention is as follows:

a phenyl fluorosilicone polymer having the structure shown in formula I:

in the formula I, x is greater than 0, and y is greater than 0; and the phenyl groups can be uniformly distributed on the molecular chain of the phenyl fluorosilicone polymer no matter how much the phenyl groups in the phenyl fluorosilicone polymer are.

According to the present invention, preferably, the phenyl groups in the phenyl fluorosilicone polymer are uniformly distributed, and the polymer has more excellent high and low temperature resistance.

According to the present invention, preferably, the phenyl fluorosilicone polymer is prepared from methyl trifluoro propyl cyclotrisiloxane (D)₃F) And the compound of the formula II is prepared by non-equilibrium copolymerization;

according to the invention, the compound of the formula II has three spatial stereoisomers, the structure of which is shown in the formula III, and the compound of the invention can be obtained by carrying out non-equilibrium copolymerization reaction on any isomer or any combination of any isomers and methyl trifluoro propyl cyclotrisiloxane.

According to the invention, the compounds of the formula II and D₃F is completely miscible with D₃F, copolymerization under the condition of equimolar, the residual proportion of the two cyclic bodies in different time periods is basically kept unchanged, and the polymerization rates are basically consistent.

According to the present invention, preferably, the preparation method of the compound of formula ii comprises the following steps:

mixing trifluoropropylmethyldichlorosilane and methylphenyldichlorosilane, dropwise adding the mixture into water for hydrolysis, continuously maintaining the reaction temperature after the dropwise adding is finished, stirring to ensure that the hydrolysis reaction is complete, washing the hydrolysate to be neutral, then adding an alkaline catalyst and a cracking assistant for cracking reaction, collecting fractions at 100-110 ℃, and finally rectifying to obtain the compound of the formula II.

According to the invention, the molar ratio of the trifluoropropylmethyldichlorosilane to the methylphenyldichlorosilane is preferably 2: 1-6: 1, when the molar ratio is lower than 2:1, the chain forming property of methylphenylsiloxane chain links is too strong, the cracking is difficult, when the molar ratio is higher than 6:1, the reaction efficiency is too low, and more preferably, the molar ratio of the trifluoropropylmethyldichlorosilane to the methylphenyldichlorosilane is 3: 1-5: 1.

According to the invention, the mass ratio of the mixture of trifluoropropylmethyldichlorosilane and methylphenyldichlorosilane to water is preferably 1: 1-1: 3.

According to the invention, preferably, the reaction temperature of the hydrolysis reaction is 40-80 ℃, more preferably 60-80 ℃, the temperature is lower than 40 ℃, the hydrolysis is incomplete, a small amount of silicon-chlorine bonds exist in hydrolysate to influence the cracking reaction, and when the temperature is higher than 80 ℃, the reaction is too fast, the overflow speed of hydrogen chloride is too fast, and the operation is difficult.

According to the invention, preferably, the alkaline catalyst is NaOH, the amount of the alkaline catalyst is 1% -3% of the mass of the hydrolysate, the amount of the alkaline catalyst is less than 1%, the cracking speed is too slow, the cracking speed is not obviously improved after the amount of the alkaline catalyst is more than 3%, but the cracking yield is obviously reduced, if LiOH is used as the cracking catalyst, the cracking temperature is too high, and if KOH is used as the cracking catalyst, phenyl is easy to fall off, and crosslinking is easy to occur.

According to the invention, preferably, the cracking assistant is one or a mixture of more of benzophenone, diphenyl sulfoxide and diphenyl sulfone, and the addition amount is 10-20% of the mass of the hydrolysate.

According to the invention, preferably, the cracking temperature is 170-220 ℃, more preferably 190-210 ℃, the temperature is lower than 170 ℃, the cracking speed is too slow, even basically no cracking is carried out, the cracking temperature is higher than 220 ℃, side reactions are increased, the cracking yield is reduced, and impurities are increased.

According to the invention, preferably, the rectification temperature is 110-120 ℃, rectification is carried out under the vacuum degree of 260-270 Pa, and 105-107 ℃ fractions can be further accurately collected to obtain a compound product of the formula II.

According to the invention, the process for the preparation of the compounds of formula II, a preferred embodiment, comprises the steps of:

adding deionized water into a reactor with a mechanical stirrer, a thermometer, a condenser and a reactor, heating to 60-70 ℃, mixing trifluoropropylmethyldichlorosilane and methylphenyldichlorosilane in a molar ratio of 3: 1-5: 1, dropwise adding the mixture into water for hydrolysis, continuously maintaining the reaction temperature and stirring for 1h after dropwise adding is finished to ensure that the hydrolysis reaction is complete, washing the hydrolysate to be neutral, then adding the hydrolysate into the reactor with a pyrolysis rectifying tower, adding NaOH accounting for 1-3% of the hydrolysate and hydrolysis auxiliary agent accounting for 10-20% of the hydrolysate, controlling the vacuum degree to be 266Pa, controlling the kettle temperature to be 190-210 ℃ for pyrolysis, collecting fractions at 100-110 ℃ to obtain a lysate, rectifying the lysate at the temperature of 110-120 ℃ under the vacuum degree of 260-270 Pa, and collecting fractions at 105-107 ℃ to obtain a compound of the formula II.

According to the present invention, the preparation method of the phenyl fluorosilicone polymer comprises the following steps:

will D₃And F and a compound shown in the formula II are mixed, vacuum dehydration is carried out, an alkaline catalyst, an end-capping agent and an auxiliary agent are added, heating polymerization is carried out for 1-3 h, acid glue is added for neutralization after polymerization is finished, and finally, the temperature is raised to 190 ℃ and low-boiling-point substances are removed in vacuum under the pressure of 266Pa, so that the phenyl fluorosilicone polymer is obtained.

According to the present invention, preferably, in the preparation method of the phenyl fluorosilicone polymer, D₃The ratio of F to the compound of the formula II is not particularly limited, and polymerization may be carried out in any ratio as required. Preferably, D₃The molar ratio of the F to the compound of the formula II is (0.1-20): 1.

according to the invention, the vacuum dehydration temperature is preferably 50-60 ℃, and the pressure is 266 Pa.

According to the present invention, preferably, the polymerization alkaline catalyst is LiOH, LiOH and D₃F prepared alkali glue, NaOH and D₃And F, adding 10-40 ppm of alkali glue and the like in terms of LiOH or NaOH.

According to the invention, preferably, the use of LiOH, LiOH and D₃The polymerization temperature of the alkali gel catalyst prepared by F is 150-170 ℃, and NaOH, NaOH and D are used₃The polymerization temperature of the alkali gel catalyst prepared by F is 110-130 ℃.

According to the present invention, preferably, the end-capping agent is a conventional end-capping agent of fluorosilicone polymer, such as vinyl fluorosilicone oil, vinyl dimethylsilanol, trimethylsilanol, etc., and the addition amount is adjusted according to the desired polymer molecular weight. The addition amount is preferably D₃0.01-10% of the total mass of the compounds F and II.

According to the present invention, it is preferable that the auxiliary is a vinyl auxiliary or the like, such as methylvinylcyclotrisiloxane, and the amount added is adjusted according to the desired vinyl content. The addition amount is preferably D₃0.001-5% of the total mass of the compounds F and II.

According to the invention, the acid colloid for neutralization is preferably composed of phosphoric acid and D₃F, preparing, wherein the neutralization time is 1-3 h to neutrality. According to the invention, the polymerization method has the yield of more than 98%.

The invention has not been described in detail, but is processed according to the conventional technology in the field.

The invention has the beneficial effects that:

1. compared with the traditional monomer copolymerized with fluorosilicone, the methyl phenyl methyl trifluoro propyl mixed cyclotrisiloxane of the compound of the formula II has good solubility, and the methyl phenyl methyl trifluoro propyl mixed cyclotrisiloxane has good solubility with D₃F, the polymerization rate is consistent, the phenyl groups can be uniformly distributed on the molecular chain of the fluorosilicone no matter the content of the phenyl groups in the prepared polyfluorosiloxane, and the high and low temperature resistance of the rubber is improved.

2. The ring body preparation method of the invention can prepare the compound with the product purity of more than 99.0 percent, and the product purity is calculated by the sum of three kinds of spatial isomers.

3. The preparation method is simple, and the phenyl fluorosilicone polymer with high yield can be obtained without complex polymerization and post-treatment processes.

Drawings

FIG. 1 shows nuclear magnetic hydrogen spectra of the compound of formula II of example 1 of the present invention.

FIG. 2 shows the nuclear magnetic hydrogen spectrum of the polymer product of formula I of example 4 of the present invention.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following specific examples.