RU2799808C2 - Method for obtaining methyl siloxane copolymers with azidopropyl and sylil hydride functional groups - Google Patents

Abstract

FIELD: organosilicon compounds.

SUBSTANCE: proposed is a method for preparing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of general formula (I), where R'=H or –(CH₂)₃-N₃, R”=–(CH₂)₃-N₃ or H, n= 10-1350, m=1-100, which consists in catalytic copolymerization of octamethylcyclotetrasiloxane and a mixture of oligomethylhydrosiloxane and bis-(azidopropyl)tetramethyldisiloxane or hydrolysis product of 3-(azidopropyl)methyldimethoxysilane and bis-(hydride)tetramethyldisiloxane by the cationic mechanism. Also proposed is a method for producing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of general formula (I) by the anionic mechanism.

EFFECT: creation of a method for producing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups, having a multifunctional structure, without the use of organic solvents, which gives a high yield of a product of a given structure.

2 cl, 3 dwg, 8 ex

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to the field of obtaining organosilicon compounds.

A new method is presented for the preparation of polymethylsiloxane copolymers with azidopropyl and hydridesilyl groups in various positions along the chain, which are reactive polymers with two independent types of functionality, capable of selective conversion according to any of them. These compounds can be effective cross-linking agents for click chemistry reactions - azide-alkyne cycloaddition and hydrosilylation of alkenes, as well as excellent modifying agents. Such copolymers can be used in various fields, from surface engineering to polymeric nanomedicine.

BACKGROUND OF THE INVENTION

The main approach to the preparation of methylsiloxane polymers with azidopropyl functional groups is the modification of polymers by polymer-analogous transformations.

A known method for producing polymethylsiloxanes with azidopropyl functional groups by substitution of the chlorine atom in methylchloropropyldimethylsiloxane polymers using sodium azide in a DMF solution [Brook M. A. Silicon in organic, organometallic, and polymer chemistry/; Michael A. Brook. – 2000].

A known method for producing azidopropyl-containing polymethylsiloxanes from polydimethylsiloxanes containing side epoxy groups by opening them using sodium azide and a platinum catalyst [Bretzler V. et al. PDMS-containing alternating copolymers obtained by click polymerization //Macromolecular Chemistry and Physics. - 2014. - T. 215. - No. 14. - S. 1396-1406].

The disadvantage of both methods is the need to preliminarily obtain nontrivial initial polymers: methylchloropropyldimethylsiloxane in the first variant and epoxy-functional polydimethylsiloxane in the second. In addition, in the first method, a high-boiling solvent is used, which is difficult to remove from the obtained polymer, and in the second method, the authors of the work resort to the use of an expensive platinum catalyst.

Known methods for obtaining functional methylsiloxane polymers using α-functional alkyl groups, for example, by hydrosilylation of functional propene CH ₂ \u003d CH-CH ₂ -FG (where FG \u003d functional group. As a silylating agent, it is possible to use both monomeric compounds - in order to convert into a polymer, and polymers with hydride groups. However, such processes usually include stages of protection - deprotection. For example, [R.Wagner, L.Richter, B.Wei land, J. Reiners, J. Weissmuller Appl. Organomet. Chem., 1996, 10, 437].

Known methods for producing methylsiloxane copolymers by ring-opening polymerization using hexaorganodisiloxanes, including those with hydride and other functional groups. At the same time, both anionic catalysts are used as catalysts [B. G. Risch, D. F. Rodriguez, K. Lyon, 1. E. McGrath and G. L. Wilkes, Polymer, 1996,37, 1229] and cationic compounds [T. N. Biggs and G. E. Le Grow, Dow Corning, US Patent US5516870, 1996; N. Mougin, P. Rempp and Y Gnanou, Makromol. Chem, 1993, 194, 2553].

There are no data on the preparation of methylsiloxane copolymers containing both azidopropylsiloxane and hydridesilyl groups.

DISCLOSURE OF THE INVENTION

The technical problem solved by the claimed invention is the creation of a new method for obtaining methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups, which are of interest as crosslinking agents, modifying components for obtaining compositions for various purposes.

The technical result achieved in the implementation of the claimed invention is to create a new technological method for obtaining methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups, having a multifunctional structure, which does not require the use of organic solvents for synthesis and leads to the formation of a polymer product with a high yield and a given ratio and position in the chain of hydridesilyl and azidopropyl functional groups.

The claimed technical result is achieved by a new method for producing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of the general formula

,

where R'= H or -(CH ₂ ) ₃ -N ₃

R '' \u003d - (CH ₂ ) ₃ -N ₃ or H

n=10-1350

m = 0-100,

consisting in the fact that catalytic copolymerization is carried out according to the cationic or anionic mechanism of octamethylcyclotetrasiloxane and a mixture of oligomethylhydrosiloxane and bis-(azidopropyl)tetramethyldisiloxane or a hydrolysis product of 3-(azidopropyl)methyldimethoxysilane and bis-(hydride)tetramethyldisiloxane.

As the main catalyst, a compound from the series is used: KOH, NaOH, RbOH, CsOH, or a quaternary ammonium or phosphonium cation, or tetramethylammonium silanolate. A sulfonic cation exchanger or H ₂ SO ₄ or RSO ₃ H or HClO ₄ or a number of Lewis acids or CF ₃ SO ₃ H can act as an acid catalyst.

Copolymerization in this way takes place in the bulk of the polymer.

The general reaction scheme has the following form (1):

where R'= H or -(CH ₂ ) ₃ -N ₃

R '' \u003d - (CH ₂ ) ₃ -N ₃ or H

BRIEF DESCRIPTION OF THE DRAWINGS

The essence of the invention is illustrated by graphic materials, where:

in fig. 1 shows ¹ H NMR spectrum obtained according to example 1;

in fig. 2 shows ^{the 28} Si NMR spectrum obtained according to example 7;

in fig. 3 shows the GPC curve obtained according to example 1.

IMPLEMENTATION OF THE INVENTION

Methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of the general formula (1) have been obtained,

(1)

where R'= H or -(CH ₂ ) ₃ -N ₃

R '' \u003d - (CH2) ₃ -N ₃ or H

n=10-1350

m = 0-100.

The method for producing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups consists in catalytic copolymerization of octamethylcyclotetrasiloxane, oligomethylhydrosiloxane or the hydrolysis product of 3-(azidopropyl)methyldimethoxysilane and bis-(azidopropyl)tetramethyldisiloxane or bis-(hydride)tetramethyldisiloxane by the cationic or anionic mechanism y. The process was carried out at 60°C in the case of cationic polymerization and at 100°C in the case of anionic polymerization, usually within 6 hours until the formation of the maximum amount of high molecular weight products, which was controlled by GPC. In FIG. 3 shows the GPC curve of a methylsiloxane copolymer with R''= 3-azidopropyl and n=20, obtained by the mechanism of anionic polymerization with molecular weight characteristics Mn= 2830, Mw/Mn = 1.8, which approximately corresponds to the calculated data.

After standard processing, the polymers were analyzed by ¹ H NMR and ²⁹ Si spectroscopy. In FIG. 1 shows the ^1H NMR spectrum of a methylsiloxane copolymer with R''=3-azidopropyl and n=20 obtained by the anionic polymerization mechanism, where the signal intensity ratio of the propyl bridge protons is 3.23 ppm. (m, 2H, _CH2 – _N3 ), 1.62 ppm (m, 2H, Si– _CH2 – _CH2– ), 0.57 ppm (m, 2H, Si–CH ₂ −) and dimethylsiloxane fragments 0.07 ppm. coincides with the theoretical one, which allows us to conclude that bis(3-azidopropyl)tetramethyldisiloxane is indeed integrated into the structure of polydimethylsiloxane and plays the role of a stopper.

The advantage of the claimed invention is a high yield of the target product, reaching 90%, as well as obtaining copolymers of a given composition and with the necessary molecular weight characteristics.

The invention can be illustrated by the following examples.

Example 1

Obtaining a methylsiloxane copolymer with R''= 3-azidopropyl and n=20 by the mechanism of anionic polymerization.

0.4 g (0.0014 mol) of bis-(azidopropyl)tetramethyldisiloxane, 2.07 g (0.0070 mol) of octamethylcyclotetrasiloxane, and 0.058 g (0.1% wt) of tetramethylammonium silaxonolate as a catalyst were added to a round-bottom, single-neck flask. The reaction mixture was stirred for 6 h at Т = 100°С. The destruction of the catalyst was carried out by heating at 150°C for an hour. Low molecular weight products were distilled off under reduced pressure. The resulting product was reprecipitated in the toluene/ethanol system. 2.3 g (yield 93%) of a colorless transparent liquid were obtained. GPC: Mn=2830, Mw/Mn=1.8. ^1H NMR (CDCl3 _, δ, ppm): 3.23 (m, 2H, _CH2 – _N3 ), 1.62 (m, 2H, Si– _CH2 –CH2–), 0.57 (m, 2H, Si– _CH2– ), 0.07 (m, _3H , Si– _CH3 ).

Example 2

Obtaining methylsiloxane copolymer with R''= 3-azidopropyl and n=80, 1349 by the mechanism of anionic polymerization is carried out according to the method similar to that described in example 1.

Example 3

Obtaining a methylsiloxane copolymer with R''= 3-azidopropyl and n= 20 by the mechanism of cationic polymerization.

0.4 g (0.0014 mol) of bis-(azidopropyl)tetramethyldisiloxane, 2.07 g (0.0070 mol) of octamethylcyclotetrasiloxane, and 0.0060 g (0.1 wt %) of trifluoromethanesulfonic acid as a catalyst were added to a round-bottom, single-necked flask. The reaction mixture was stirred for 15 minutes at room temperature, and why 6 hours at a temperature of 60°C. Na ₂ CO ₃ was added to neutralize the acid. The resulting product was dissolved in toluene and filtered off the salt through a filter paper. Toluene was distilled off under reduced pressure. 2.42 g (yield 98%) of a colorless transparent liquid were obtained. GPC: Mn, 1950, Mw/Mn = 1.7. ^1H NMR (CDCl3 _, δ, ppm): 3.23 (m, 2H, _CH2 – _N3 ), 1.62 (m, 2H, Si– _CH2 –CH2–), 0.57 (m, 2H, Si– _CH2– ), 0.07 (m, _3H , Si– _CH3 ).

Examples 4, 5

The preparation of a methylsiloxane copolymer with R''= 3-azidopropyl and n= 10, 80, 1349 by the mechanism of cationic polymerization is carried out according to a method similar to that described in example 3.

Example 6

Obtaining a methylsiloxane copolymer with R''= 3-azidopropyl n=20, m= 1 by the mechanism of cationic polymerization.

4 g (0.0130 mol) of bis-(azidopropyl)tetramethyldisiloxane, 20 g (0.0670 mol) of octamethylcyclotetrasiloxane, 0.84 g of oligomethylhydrosiloxane (0.0002 mol) and 0.12 g (0.1 wt %) of trifluoromethanesulfonic acid as a catalyst were added to a round-bottom one-necked flask. The reaction mixture was stirred for 15 minutes at room temperature, and why 8 hours at a temperature of 80 °C. Na ₂ CO ₃ was added to neutralize the acid. The resulting product was dissolved in toluene and filtered off the salt through a filter paper. Toluene was distilled off under reduced pressure. Received 17.5 g (yield 70%) of a substance that is a transparent liquid of yellowish color. GPC: Mn=1900, Mw/Mn=1.8. ^1H NMR (CDCl3 _, δ, ppm): 4.68 (s, 1H, Si–H), 3.23 (m, 2H, _CH2 – _N3 ), 1.62 (m, 2H, Si– _CH2 – _CH2– ), 0.57 (m, 2H, Si– _CH2– ), 0.07 (m, 3H, Si– _CH3 ).

Example 7

Obtaining a methylsiloxane copolymer with R''= 3-azidopropyl and n=83, m= 17 by the mechanism of cationic polymerization.

0.15 g (0.0005 mol) of bis-(azidopropyl)tetramethyldisiloxane, 3.1 g (0.0104 mol) of octamethylcyclotetrasiloxane, 0.4 g of oligomethylhydrosiloxane (0.0001 mol) and 0.005 g (0.1% wt.) of trifluoromethanesulfonic acid as a catalyst were added to a round-bottomed single-necked flask. a. The reaction mixture was stirred for 15 minutes at room temperature, and why 8 hours at a temperature of 60°C. Na ₂ CO ₃ was added to neutralize the acid. The resulting product was dissolved in toluene and filtered off the salt through a filter paper. Toluene was distilled off under reduced pressure. Received 2.5 g (yield 81%) of the substance, which is a transparent liquid of yellowish color. GPC: 8000, Mw/Mn = 1.9. ^1H NMR (CDCl3 _, δ, ppm): 4.68 (s, 1H, Si–H), 3.23 (m, 2H, _CH2 – _N3 ), 1.62 (m, 2H, Si– _CH2 – _CH2– ), 0.57 (m, 2H, Si– _CH2– ), 0.07 (m, 3H, Si– _CH3 ). ²⁹ Si NMR: δ 7.13, -20.61, -21.96, -37.55.

Example 8

Obtaining a methylsiloxane copolymer with R''=hydride n=100, m=100 by the mechanism of cationic polymerization.

1.96 g (0.0137 mol) of the hydrolysis product of 3-azidopropylmethyldimethoxysilane, 1.06 g (0.0036 mol) of octamethylcyclotetrasiloxane, 0.024 g of bis-(hydride)tetramethyldisiloxane (0.00017 mol) and 0.005 g (0.1% wt.) ) trifluoromethanesulfonic acid as a catalyst. The reaction mixture was stirred for 15 minutes at room temperature, and why 8 hours at a temperature of 60°C. Na ₂ CO ₃ was added to neutralize the acid. The resulting product was dissolved in toluene and filtered off the salt through a filter paper. Toluene was distilled off under reduced pressure. Received 2.7 g (yield 84%) of the substance, which is a transparent liquid of yellowish color. GPC: Mn=19000, Mw/Mn=1.5. ^1H NMR (CDCl3 _, δ, ppm): 4.68 (s, 1H, Si–H), 3.23 (m, 2H, _CH2 – _N3 ), 1.62 (m, 2H, Si– _CH2 – _CH2– ), 0.57 (m, 2H, Si– _CH2– ), 0.07 (m, 3H, Si– _CH3 ). ²⁹ Si NMR: δ -22.39-(-21.20).

Claims (14)

1. Method for producing methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of the general formula , where R'= H or -(CH ₂ ) ₃ -N ₃ R '' \u003d - (CH ₂ ) ₃ -N ₃ or H n=10-1350 m = 1-100, which consists in carrying out catalytic copolymerization of octamethylcyclotetrasiloxane and a mixture of oligomethylhydrosiloxane and bis-(azidopropyl)tetramethyldisiloxane or the hydrolysis product of 3-(azidopropyl)methyldimethoxysilane and bis-(hydride)tetramethyldisiloxane by the cationic mechanism at 60°C using a compound from the series: sulfonic cationite, H ₂ SO ₄ as a catalyst , RSO ₃ H, HClO ₄ , Lewis acids, CF ₃ SO ₃ H. 2. Method for obtaining methylsiloxane copolymers with azidopropyl and hydridesilyl functional groups of the general formula , where R'= H or -(CH ₂ ) ₃ -N ₃ R '' \u003d - (CH ₂ ) ₃ -N ₃ or H n=10-1350 m = 1-100, consisting in the fact that they carry out catalytic copolymerization according to the anionic mechanism of octamethylcyclotetrasiloxane and a mixture of oligomethylhydrosiloxane and bis-(azidopropyl)tetramethyldisiloxane at 100°C using as a catalyst a compound from the series: KOH, NaOH, RbOH, CsOH, quaternary ammonium or phosphonium cation, tetramethylammonium silanolate.