RU2352596C2 - Polyfluoralkoxyphosphazene (co) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: there are disclosed polyfluoralkoxyphosphazene (co)polymers of general formula:

, R is (OCF₂)_m1 or (OCF₂)_m1 and (OCF₂)_m2 only; _m1=1-8, _m2=3-8, and _m1≠_m2; n=1000-5000 for making oil-resistant, gasoline-proof and antifreeze materials.

EFFECT: invention can be used in various arts for making oil-resistant, gasoline-proof and highly antifreeze materials.

6 ex, 1 tbl

Description

The present invention relates to the production of new polyfluoroalkoxyphosphazene (co) polymers of the general formula:

where R is only (OCF ₂ ) _m1 or (OCF ₂ ) _m1 and (OCF ₂ ) _m2 ,

m1 = 1-8, m2 = 3-8, with m1 ≠ m2,

n = 1000-5000.

Such (co) polymers can be used in various fields of technology, for example, in aeronautical engineering, for the manufacture of oil and petrol resistant materials with high frost resistance.

Polyfluoroalkoxyphosphazene polymers of the general formula are known.

which are obtained by the interaction of polydichlorophosphazene with lithium fluoroalcoholate (Ed. certificate. USSR 217638, prior. 12.05.66). However, the glass transition temperature of such copolymers is equal to -77 ÷ -80 ° C, which limits the scope of their use.

Polyfluoroalkoxyphosphazene copolymers of the general formula are known

obtained by the interaction of polydichlorophosphazene with a mixture of sodium fluoroalcoholates taken as a hot solution in tetrahydrofuran (Rose S.H., J. Polym. Sci, Part B, b, 837 (1968)).

However, the glass transition temperature of the above-mentioned copolymers is only -77 ° C, which clearly limits the scope of their use.

The closest analogue in their purpose are polyfluoroalkoxyphosphazene polymers of the general formula

with a pier. mass (M _w ) = 1250600, obtained by the interaction of high molecular weight polydichlorophosphazene with fluoroalkoholate Li in diethyl ether at 35 ° C.

These copolymers have increased frost resistance in comparison with the known ones, however, their glass transition temperature is not low enough, namely -99 ° С (V.I.Sharov, G.A. Ivanova and others. The influence of synthesis conditions on the phase-aggregate state of fluoroalkoxyphosphazene polymers, DAN 1978, vol. 239, No. 5, p. 1113).

The objective of this technical solution is to create a polyfluoroalkoxyphosphazene polymer with improved frost resistance.

The task is achieved by the synthesis of (co) polymers of the general formula (1).

Such polyfluoroalkoxyphosphazene (co) polymers are prepared by reacting high molecular weight polydichlorophosphazene with the corresponding lithium or sodium fluoroalkylate (s) of the general formula CF ₃ O (CF ₂ O) _p CF ₂ CH ₂ OMe, where Me is Na, Li, p = 1- 8 at a molar ratio of NPCl ₂ : fluoroalkylate = 1: 2.2.

The synthesis of fluoroalkylates is carried out by reacting the corresponding alcohols with a 10% excess of Na or Li at a temperature of 15-30 ° C for 7-12 hours in absolute diethyl ether or tetrahydrofuran followed by separation from the unreacted metal.

The interaction of fluoroalcoholate with polydichlorophosphazene is carried out with vigorous stirring for ~ 40 hours at a temperature of 40-45 ° С until the chlorine in polydichlorophosphazene is completely replaced by polyfluoroalkoxyl groups, moreover, polydichlorophosphazene is introduced into the fluoroalcoholate solution in the form of a 10% toluene solution for ~ 1 hour.

The obtained polyfluoroalkoxyphosphazene (co) polymer is first washed with a ~ 20% aqueous-alcoholic solution to liberate the precipitated LiCl or NaCl and unreacted fluoroalkylates Na or Li, and then with water until the reaction to Cl disappears in the washings, after which it is dried at 50-60 ° C under vacuum (P = 2-4 mm Hg).

The composition of the synthesized (co) polymer is determined using elemental analysis and ¹⁹ _F NMR spectroscopy.

¹⁹ _F NMR spectra were recorded ^{on a} Broker AM-500 instrument, for which 5-10% solutions of (co) polymers in hexafluorobenzene were used. The viscosity of the obtained (co) polymers, their glass transition temperature and the temperature at which they decompose (in argon in differential thermal analysis - DTA) are also determined.

The following examples illustrate the invention.

Example 1

1.4 Li in 20 ml of absolute diethyl ether are fed into a reactor equipped with a thermometer, a dropping funnel, and a stirrer, then a solution of 46.4 g (0, 2 mol) of alcohol CF ₃ OCF ₂ OCF ₂ CH ₂ OH in 45 ml of diethyl ether, after which the reaction mass is continued to mix for 5 hours.

A solution of lithium fluoroalcoholate is separated from unreacted lithium, after which a solution containing 9.25 g (0.08 mol) of a polydichlorophosphazene polymer in 170 ml of toluene is added to it over 1 hour. The contents of the reactor with vigorous stirring and a temperature of 40-45 ° C are maintained for 40 hours.

Next, the resulting polymer is washed ten times with a 20% aqueous-alcoholic solution, and then with water. The polymer is dried under vacuum (P = 2-4 mm Hg) at a temperature of 50-60 ° C to constant weight.

Obtain 37.3 g (yield 92%) of high molecular weight polyfluoroalkoxyphosphazene polymer.

The homopolymer is not soluble in hexane, benzene, toluene, diethyl ether, acetone. Soluble in perfluorobenzene.

^Intrinsic viscosity / η / ^{20 deg. C} in hexafluorobenzene = 1.70 dl / g. Molecular mass (M _w ) = 2286500, glass transition t = -122 ° C. The beginning of polymer decomposition in argon medium is 325 ° С.

Elemental analysis

Found,%: C - 19.35; H 0.65; N - 2.54; P - 5.86; F - 51.84.

Calculated for C ₈ H ₄ O ₆ NPF ₁₄ ,%: C - 19.00; H 0.80; N 2.76; P - 6.11; F - 52.46.

According to elemental analysis and ¹⁹ _F NMR spectroscopy, a polymer is obtained corresponding to Formula 1, where R is (OCF ₂ ) _m , m = 1, n = 4500.

Example 2

The synthesis of polyfluoroalkoxyphosphazene copolymer is carried out according to the method described in example 1.

From 23.2 g (0.1 mol) of alcohol CF ₃ OCF ₂ OCF ₂ CH ₂ OH, 36.4 g (0.1 mol) of alcohol CF ₃ O (CF ₂ O) ₃ CF ₂ CH ₂ OH, 5, 0 g of sodium and 11.0 g (0.09 mol) of a polydichlorophosphazene polymer in 150 ml of toluene give 5.20 g (90% yield) of a high molecular weight polyfluoroalkoxyphosphazene copolymer.

Elemental analysis

Found,%; C = 18.62; H = 0.52; N = 2.02; P = 5.12; F = 53.21

Calculated C ₁₀ H ₄ O ₈ NPF ₁₈ ,%: C = 18.78; H = 0.63; N = 2.13; P = 4.85; F = 53.52

The copolymer has the same solubility as the homopolymer of example 1.

^Intrinsic viscosity (in hexafluorobenzene) / η / ^{20 degrees C} = 2.21 dl / g

Molecular Weight (M _w ) = 2502600,

glass transition t = -128.5 ° C

The beginning of decomposition in argon - 388 ° С

According to elemental analysis and ¹⁹ _F NMR spectroscopy, a copolymer containing 50 mol.% Polyfluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m1 , m1 = 1 and 50 mol.% Fluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m2 , m2 = 3, n = 5000.

Example 3

The synthesis of polyfluoroalkoxyphosphazene copolymer is carried out according to the method described in example 1.

Of 12.5 g (0.02 mol) of alcohol CF ₃ O (CF ₂ O) ₇ CF ₂ CH ₂ OH, 125.0 g (0.18 mol) of alcohol CF ₃ O (CF ₂ O) ₈ CF ₂ CF ₂ OH, 5.05 g sodium and 11.0 g (0.09 mol) of a polydichlorophosphazene polymer in 150 ml of toluene give 102.0 g (80% yield) of a high molecular weight polyfluoroalkoxyphosphazene copolymer.

The copolymer has the same solubility as the copolymer of example 1.

^Intrinsic viscosity / η / ^{20 deg} . ^C = 1.85 dl / g (in hexafluorobenzene).

Molecular Weight (M _w ) = 1852400;

t glass transition = -178.0 ° C.

The beginning of the decomposition of the copolymer in argon medium is 312 ° С.

Elemental analysis

Found,%: C = 18.32; H = 0.25; N = 0.82; P = 2.02; F = 55.12.

Calculated for C _21.8 H ₄ O _19.8 NPF _41.6 ,%: C = 18.45; H = 0.28; N = 0.91; P = 2.18; F = 55.67.

According to the data of elemental analysis and ¹⁹ _F NMR spectroscopy, a copolymer corresponding to formula 1 and containing 10 mol.% Polyfluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m1 , m1 = 7 and 90 mol.% Fluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m2 , m2 = 8, n = 1300.

Example 4

According to the method described in example 1,

from 53.62 g (0.18 mol) of alcohol CF ₃ O (CF ₂ O) ₂ CF ₂ CH ₂ , 8.6 g (0.02 mol) of alcohol CF ₃ O (CF ₂ O) ₄ CF ₂ CF ₂ OH, 5.02 g of sodium and 11.0 g (0.09 mol) of a polydichlorophosphazene polymer in 150 ml of toluene give a high molecular weight polyfluorophosphazene copolymer in 82% yield.

The copolymer has the same solubility as the copolymer of example 1.

^Intrinsic viscosity / η / ^{20 deg} . ^C = 1.65 dl / g (in hexafluorobenzene).

Molecular weight = 1855300;

glass transition t - 142 ° С

The beginning of the decomposition of the copolymer in argon 385 ° C

Elemental analysis

Found,%: C = 18.66; H = 0.54; N = 1.96; P = 4.44; F = 53.21

Calculated for C _10.4 H ₄ O _8.4 NPF _18.8 ,%: C = 18.75; H = 0.60; N = 2.10; P = 4.65; F = 53.68.

According to the data of elemental analysis and ¹⁹ _F NMR spectroscopy, a copolymer corresponding to formula 1 and containing 90 mol.% Polyfluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m1 , m1 = 2 and 10 mol.% Fluoroalkoxyphosphazene units, where R = (OCF ₂ ) _m2 , m2 = 4, n = 3600.

Example 5

According to the method described in example 1,

from 9.42 g (0.019 mol) of alcohol CF ₃ O (CF ₂ O) ₅ CF ₂ CH ₂ OH, 0.133 g of lithium and 1.04 g (0.009 mol) of a polydichlorophosphazene polymer in 18 ml of toluene, 8.3 g of high molecular weight polyfluoroalkoxyphosphazene are obtained copolymer with a yield of 90%.

The polymer has the same solubility as in example 1.

^Intrinsic viscosity / η / ^{20 deg} . ^C = 1.25 dl / g (in hexafluorobenzene).

Elemental analysis

Found,%: C = 18.72; H = 0.45; N = 1.42; P = 3.06; F = 54.62

Calculated for C ₁₆ H ₄ O ₁₄ NPF ₃₀ ,%: C = 18.55; H = 0.40; N = 1.35; P = 3.00; F = 55.10.

According to the data of elemental analysis and ¹⁹ _F NMR spectroscopy, a polymer is obtained corresponding to formula 1, where R = (OCF ₂ ) _m1 , m1 = 5; n = 1440.

Example 6

From 20.8 g (0.03 mol) of alcohol CF ₃ O (CF ₂ O) ₈ CF ₂ CH ₂ OH, 0.21 g of lithium and 1.62 g (0.014 mol) of a polydichlorophosphazene polymer in 20 ml of toluene, high molecular weight polyfluoroalkoxyphosphazene is obtained polymer in 90% yield.

The solubility of the polymer is the same as in example 1.

^Intrinsic viscosity / η / ^{20 deg} . ^C = 1.20 dl / g.

Molecular mass = 1470000, t glass transition = -180 ° C

The beginning of the decomposition of the polymer in an argon medium of 295 ° C

Elemental analysis

Found,%: C = 18.10; H = 0.35; N = 0.95; P = 2.31; F = 55.21

Calculated for C ₂₂ HO ₂₀ NPF ₄₂ ,%: C = 17.75; H = 0.30; N = 1.00; P = 2.17; F = 55.84.

According to elemental analysis and ¹⁹ _F NMR spectroscopy, the synthesized polymer corresponds to formula 1, where R = (OCF ₂ ) _m1 , m1 = 8; n = 1000.

On the basis of (co) polymers synthesized according to examples 1-6, receives the composition of the following composition, parts by weight:

(co) polymer - 100,

magnesium oxide - 6.0,

modified aerosil - 30.0,

Dicumyl peroxide - 0.4.

Vulcanization is carried out according to a two-stage method;

Stage I - 20 min at 160 ° C in the press;

Stage II - thermostating at 100 ° C for 24 hours.

Below are the test data of vulcanizates based on the proposed (co) polymers

Table The properties Example No. one 2 3 four 5 6 Glass transition temperature, ° С -122.0 -128.5 -177.0 -142.0 -148.0 -180.0 The coefficient of frost resistance to elastic recovery at -70 ° C 0.58 0.60 0.80 0.60 0.60 0.80 Swelling in kerosene TS-1 (100 ° C × 3 days) k ₁ ^* 1,0 1,0 1,0 1,0 1,0 1,1 k ₂ ^** 1,1 1,0 1,0 1,0 1,0 1,1 Swelling, wt.% 2.5 2,4 2,3 2.2 2.1 2.0 k ₁ ^* - coefficient of change in tensile strength after swelling k ₂ ^** - coefficient of change in elongation

Thus, the proposed polyfluoroalkoxyphosphazene (co) polymers possess, in addition to good oil and gas resistance, increased frost resistance as compared to the known (co) polymers (the glass transition of the (co) polymers is -120 ÷ -180 ° C).

Claims (1)

Polyfluoroalkoxyphosphazene (co) polymers of the general formula

where R is only (OCF ₂ ) _m1 or (OCF ₂ ) _m1 and (OCF ₂ ) _m2 ,
m1 = 1-8, m2 = 3-8, with m1 ≠ m2,
n = 1000-5000,
for the manufacture of oil-, petrol-, frost-resistant materials.