DE2709280C2 - Process for the production of poly (tetramethylene ether) glycol - Google Patents

Description

The invention thus provides a process for the preparation of a poly (tetramethylene ether) glycol with ester end groups by polymerizing tetrahydrofuran or an alkyl-substituted tetrahydrofuran, which is characterized in that the polymerization is carried out in the range from 0 to 120 ^° C. in a reaction medium which contains the following components:

(A) an acylium ion precursor in at least an initial concentration of 0.1 to 15 mole percent on the reaction mass,

(B) a catalytically effective amount of a catalyst in the form of a polymer of ethylenically unsaturated Monomers, the polymer

(1) Contains groups of the following general formulas

I · Z

C - D or C - D

I I

SO3H R

X-C-Y

SO3H

in which

denotes the polymer chain or a segment thereof,

D is a hydrogen atom, an aliphatic or aromatic hydrocarbon radical with 1

represents up to 10 carbon atoms, a halogen atom or a segment of the polymer chain,

X and Y each represent a hydrogen atom, a halogen atom (especially a fluorine atom) or an aliphatic or aromatic hydrocarbon radical with 1 to 10 carbon atoms, but at least one of the radicals X and Y must be a fluorine atom,

R is a linear or branched linking radical with up to 40 carbon atoms in

the main chain represents and

Z represents a hydrogen atom, a halogen atom (especially a fluorine atom) or an aliphatic atom or aromatic hydrocarbon radical with 1 to 10 carbon atoms, as

(2) is practically free of functional groups that could interfere with the reaction, as well as, if applicable

(C) an aliphatic carboxylic acid having 1 to 36 carbon atoms in a concentration of 0.1 to

10% by weight, based on the tetrahydrofuran, with a weight ratio of acylium ion precursor: acid from 20: I to 0.1: 1.

The polymerization probably includes the stages of the start reaction (initiation), the chain growth, chain transfer, redistribution or disproportionation, chain termination and catalyst regeneration. These stages take place simultaneously and competitively; it is believed that they are after the following example reaction equations run

Start reaction

R '--C

NfSO ₃ H + O +

R'-C

Catalyst acylium ionator precursor

Il

R'-C- ⁰ O NfSOf + R'-COOH (1)

Acyloxonium ion

¹⁵ chain growth

R 'C— ^β Ο

Chain transfer O

Il

R'-CO-

NfSOf + nO

R'-C [O (CH ₂ ) ₄ ] "- ^ffl O

O R '-C

NfSOf +

R '- ^ C

V O

THF

R '- CO ~ O (CH ₂ ) ₄ OC - R' +

R '—C— ^e O NfSOf

Redistribution

O

R '--C

R '-CO-OC-R' +

O O

THF

R '--C

Chain break O

R '- CO ~ ^e O

NfSOf + R '-COOH

O

R '- CO ~ O (CH ₂ ) ₄ OC - R' + H® + NfSOf

⁶⁵ Regeneration of the catalyst NfSOj ¹ + Η

NlSO ₃ H NiSOf (2)

In the above reaction equations, R 'stands for a hydrogen atom or a hydrocarbon radical, preferably an alkyl radical having 1 to 36 carbon atoms, NfSO ₃ H for the catalyst and — for the poly (tetramethylene ether) chain.

When the reactions are complete, the catalyst can be separated from the reaction mass and reuse. 5

The THF used as a reaction component can be any commercial product. It preferably has a water content of less than 0.001% by weight and a peroxide content of less than 0.002 % By weight and preferably contains an oxidation inhibitor (such as butylated hydroxybluene) for the purpose of prevention undesired byproduct formation and discoloration.

If desired, 0.1 to 50% by weight (based on the THF) of an io copolymerizable with THF can be added

'™ Use alkyltetrahydrofurans as an additional reaction component. Such alkyltetrahydrofurans can can be represented by the following general formula:

^R 2 -C CR ₃ I.

i i (7) '- I

R ₁ - CC - R ₄ F

O ^

in which (at least) any radical R ₁ , R ₂ , R ₃ or R _{4 is} an alkyl radical having 1 to 4 carbon atoms ρ

and the remaining R radicals are hydrogen atoms. £ '

Specific examples of these alkyltetrahydrofurans are 2-and 3-Methyltetrahydröfuran Methyltetrahydrofu- ψ

ran. yy *

The catalysts used according to the invention are homopolymers of ethylenically unsaturated monomers

mercn (a) which contain groups such that the polymer obtained groups of the following general $

Formulas contains: ψ

I ³⁰ ] CD (8) } <

SO ₃ H ϊ

or

C-D (9)

I 40

X-C-Y

SO ₃ H ⁴⁵

wherein

the polymer chain or a segment of the polymer chain,

D is a hydrogen atom, an aliphatic or aromatic hydrocarbon radical having 1 to 10 coal ⁵⁰

fuel atoms, a halogen atom or a segment of the polymer chain, X and Y represent a hydrogen atom, a halogen atom (especially a fluorine atom) or an aliphatic or aromatic hydrocarbon radical with 1 to 10 carbon atoms, but at least one

the radicals X and Y must be a fluorine atom,
R is a linear or branched linking radical with up to 40 carbon atoms in the main ⁵⁵

chain and
Z represents a hydrogen atom, a halogen atom (especially a fluorine atom) or an aliphatic or

aromatic hydrocarbon radical with 1 to 10 carbon atoms

mean ⁶⁰

or copolymers of monomers (a) with at least one other copolymerizable, ethylenically unsaturated Monomers (b).

The linking radical R in the formula (9) can be homogeneous (like an alkylene radical) or heterogeneous (like an alkylene ether radical). In the case of the preferred catalysts, this linking radical has 1 to 20 carbon atoms in the main chain. In the case of the particularly preferred catalysts, R is a radical of the general formula ⁶⁵

• 0 —CF ₂ -CF-

CF ₃ J

-Ο —CF,

Examples of suitable monomers (a) are trifluorovinylsulfonic acid, straight-chain or branched-chain vinyl monomers, which contain sulphonic acid group precursors, and perfluoroalkyl vinyl ethers which contain sulphonic acid group precursors contain. Examples of suitable monomers (b) are ethylene, styrene, vinyl chloride, vinyl fluoride, Vinylidene fluoride, chlorotrifluoroethylene, bromotrifluoroethylene, vinyl ether, perfluoroalkyl vinyl ether, butadiene, Tetrafluoroethylene and hexafluoropropylene.

Homopolymerization and copolymerization can be carried out according to US Pat. No. 3,784,399 or those cited therein Patent specifications are made. The monomer proportions are chosen so that the polymers obtained the correct equivalent weight is given.

The catalysts have equivalent weights from 950 to 1500, preferably from 1100 to 1300. The equivalent weight of a catalyst is that weight (in g) which contains one equivalent of sulfonic acid groups. It can be determined by titration.

The catalyst preferably has such a solubility that not at the reaction temperature dissolve greater than about 5% by weight in the reaction mass when the reaction occurs during any one of the following Period is carried out discontinuously. The solubility is determined gravimetrically.

The solubility of the catalyst should be as low as possible, since this increases the loss of catalyst is prevented and a performance of the process over long periods of time without a catalyst replacement is made possible. The solubility is preferably not more than about 1% by weight and in particular is below the limit value that can be determined using the currently available analytical methods.

The catalyst should have functional groups (other than -SOjH groups) which control the polymerization reaction could disturb, be practically free. "Virtually free" means that the catalyst has a low May contain a number of such groups, but not so many that the implementation is impaired or that Product becomes contaminated. Specific examples of such groups are carboxyl, hydroxyl and amino groups.

Catalysts whose polymer chains consist of perfluorocarbon monomers are preferably used. Examples of such monomers are tetrafluoroethylene (TFE), hexafluoropropylene, chlorotrifluoroethylene (CTFE), bromotrifluoroethylene and perfluoroalkyl vinyl ether. Mixtures of these monomers can also be used.

Copolymers of TFE or CTFE with a sulfonic acid group precursor are particularly preferred as catalysts containing perfluoroalkyl vinyl ethers. Most preferred within this class Copolymers of TFE or CTFE with a monomer of the general formula

CF ₂ = C-

Q-CF ₂ -C-

-0-CF ₂ -CF ₂ -SO ₂ F

(10)

Ibis 10

These polymers are produced in the sulfonyl fluoride form and then according to US Pat. No. 3,692,569 for Hydrolyzed acid form.

Most preferred as catalysts are copolymers of TFE with monomers of formula (K)), which have corresponding monomer weight ratios of (50 to 75): (25 to 50). Such copolymers with equivalent weights of 1100, 1150 and 1500 are used by E. I. DU PONT DE NEMOURS AND COMPANY marketed as perfluorosulfonic acid resin Nafion®.

The catalyst is present in the reaction mass in a catalytically effective amount. This corresponds to the Usually a concentration of 0.01 to 30% by weight, preferably 0.05 to 15% by weight, in particular 0.1 up to 10% by weight, based in each case on the mass.

Any compound which is capable of forming the acyloxonium ion according to equation (1) under the reaction conditions can serve as acylium ion precursor. _β

In the present context, an "acylum ion" is an ion with the structure R'-C = O, where R 'is a hydrogen atom or a hydrocarbon radical, preferably an alkyl radical having 1 to 36 carbon atoms, means

Typical examples of such precursors are the acyl or acid halides and carboxylic acid anhydrides. Anhydrides of carboxylic acids, the carboxylic acid components of which have 1 to 36 carbon atoms (in particular 1 to 4 carbon atoms) are preferred.

Specific examples of these anhydrides are acetic acid, propionic acid, and formic acid / acetic acid anhydride. Acetic anhydride is preferred because of its effectiveness as an anhydride.

The acylium ion precursor is in the reaction mass at least initially at a concentration of 0.1-15 MoI-% (preferably 0.7 to 10 mol%) contain.

The molecular weight of the polymer product can be limited by taking into account the reaction mass an aliphatic carboxylic acid having 1 to 36 carbon atoms (preferably 1 to 5 carbon atoms) is incorporated. Acetic acid is preferred for this purpose because of its low cost and effectiveness.

The weight ratio of acylium ion precursor / acid is in the range from 20: 1 to 0.1: 1 and is

preferably 10: 1 to 0.5: 1. In general, the higher the molecular weight of the product, the lower Carboxylic acid is used.

The aliphatic carboxylic acid is added to the reaction mass in a concentration of 0.1 to 10% by weight (preferably from 0.5 to 5% by weight), based on the THF, incorporated.

Since the preferred acylium ion precursor, i. H. Acetic anhydride, with THF and the catalyst to the appropriate If the acid reacts, a separate addition of acid is not necessary in this case. For an improved However, in terms of molecular weight control, addition of acid is generally desirable.

To obtain a product that has an average molecular weight advantageous for technical purposes (Number average) from 650 to 30,000, the acylium ion precursor and the carboxylic acid become in the reaction mass preferably in a common (combined) concentration of 0.5 to 20% by weight (preferably 1 to 10% by weight), based in each case on the reaction mass, are used.

The polymerization can be carried out batchwise or continuously.

In the discontinuous procedure, the correct proportions of THF, acylium ion precursor, The catalyst and the carboxylic acid are placed in a reactor and stirred, with optimal reaction conditions be maintained. When the reactions are complete, the catalyst can be removed from the Separate the reaction mass and then the separation of the product from the remaining reaction mass make.

In the case of continuous operation, the reaction is preferably carried out in an analogous manner in one with backmixing working slurry reactor with constant stirring and continuous addition of Reaction components and continuous product separation through. "Optionally, the procedure in take place in a tubular reactor.

In a tubular reactor, the reaction takes place under intermittent flow conditions, the premixed Reaction components are stirred through the reactor filled or "packed" with the catalyst will. The flow is continuous with little or no mixing of the Starting material takes place with the partially converted reaction components and wherein the reaction components implement in the course of their transport.

The tubular reactor is preferably oriented vertically, with the reaction components through upwards oen catalyst flow. This helps to keep the catalyst suspended and to allow the reaction components to flow more freely. The reaction components can also be passed downwards through the reactor conduct, but there is a risk that the catalyst will be compressed and the reactant is current inhibited.

In both the slurry reactor and the tubular reactor, the temperature and Concentration of the reaction components in the reaction zone and the flow rate (throughput) the reaction components in and out of the reaction zone so that per pass through the Reactor 5 to 85 wt% (preferably 15 to 60 wt%, especially 15 to 40 wt%) of the THF in PTMEG converted with ester end groups.

Furthermore, one preferably works in such a way that the reaction components have passed through the reactor each time at least 40% by weight (especially 80 to 90% by weight) of the acylium ion precursor are consumed.

With the correct adjustment of the concentrations of the reactants in the feed stream, the throughputs and the temperature, all of these conditions can, as a rule, with a residence time of the reaction components (in a reactor with continuous operation) from 10 minutes to 2 hours (preferably from 15 up to 60 minutes, in particular from 20 to 45 minutes).

The residence time (in minutes) is determined by measuring the volume (in ml) of the reaction zone and dividing the value obtained by the throughput (in ml / min.) of the reaction components through the reactor certainly. In a slurry reactor, the reaction zone corresponds to the total volume of the reaction mixture, while in a tubular reactor it represents the zone containing the catalyst. j

Both in the batchwise and in the continuous procedure, the polymerization is usually [

carried out at atmospheric pressure. However, reduced or increased pressure can also be used to to facilitate the regulation of the temperature of the reaction mass during the reaction.

The temperature of the reaction mass is in the range from 0 to 120 ⁰ C, preferably 22-65 ° C, maintained. Oxygen is preferably kept away from the reaction zone. For this purpose the process can be carried out in an inert atmosphere, e.g. B. an atmosphere of anhydrous nitrogen or argon.

The reaction time required to achieve a given THF / polymer conversion rate depends on the process conditions. It therefore fluctuates with temperature, pressure and concentrations the reactant, the catalyst and like factors. Works in continuous operation however, in general, a residence time of 10 minutes to 2 hours, preferably 15 to 60 hours Minutes, in particular 20 to 45 minutes, results. In the case of discontinuous operation, the process takes a long time usually 1 to 24 hours.

When the polymerization is complete, the catalyst can be removed by filtration, or decanting Separate the centrifugation from the reaction mass and reuse. When working continuously the catalyst can simply be left in the reactor while fresh reaction components are fed in and discharges the product

Both in the batchwise and in the continuous mode of operation, the polymer product is after the Catalyst removal separated from the reaction mass. For this purpose, the remaining, not implemented Components, d. H. THF, acylium ion precursor and carboxylic acid, extracted, distilled off or with Stripped of water vapor or an inert gas (e.g. nitrogen).

The obtained poly (tetramethylene ether) diacetate (PTMEA) can physically be a substance from a clear, viscous liquid to a waxy solid. The average molecule

The number average weight of the product can reach the high value of 30,000, but is generally lower in the range from 650 to 5000, preferably from 650 to 2900.

The number average molecular weight is determined by end group analysis using conventional methods determined by spectroscopic methods.

One can keep the molecular weight of the PTMEA within any desired range, by calculating the ratio of the carboxylic acid to the acylium ion precursor in the starting material, the total amounts the carboxylic acid and precursor in the starting material, the temperature of the reaction mass (within certain limits) and the catalyst concentration varies as well as the residence time of the reaction components regulates in the reaction zone. Higher amounts of carboxylic acid and / or acylium ion precursors generally yield polymers with lower molecular weights. Favor lower reaction temperatures the formation of polymers with higher molecular weights, while higher temperatures as well higher catalyst concentrations favor the formation of polymers with lower molecular weights.

Examples

The "catalyst" used in the examples is a powdery perfluorosulfonic acid resin (Nafion ^a ) with an equivalent weight of 1100 and an average grain size of 0.2 to 0.5 mm.

All polymerizations are carried out at 22 ° C. and normal pressure, unless otherwise stated.
The sieve mesh sizes listed refer to the Tyler sieve series.

The percentages relate to weight, unless stated otherwise.
Although molecular weights are not determined for some samples, the intrinsic viscosity values given in their place are to be regarded as a yardstick for fluctuations in molecular weight. The intrinsic viscosity is the value obtained by extrapolating the ratio of the specific viscosity of a given solution to the concentration of this solution to the concentration zero.

example 1

Is added a 1.75 g sample of the catalyst in a flame-dried and weighed flask, which is then up to a pressure of 10 ^"5 mm Hg evacuated and heated for 16 hours to 120 ⁰ C. Thereafter, weigh the flask again and provides found that 1.6 g of anhydrous catalyst were present.

Then 134.8 g of THF dried over lithium aluminum hydride and 1.08 g of acetic anhydride are added distilled in the flask by the usual vacuum method. The mixture is stirred for 24 hours. 500 ml (444 g) of THF are then added in order to reduce the viscosity of the solution, and the mixture is filtered the catalyst off.

The unpolymerized THF is then evaporated off under reduced pressure. After drying at 80 ⁰ C / 120 mm Hg to 89.8 g (degree of conversion of 66 wt .-% THF) is polymer having an intrinsic viscosity [;,] of 1.05 and one for the acetate end groups characteristic IR absorption peak at 1750 cm- '.

If one works in an analogous manner, but in the absence of acetic anhydride (ie under conditions not according to the invention), 51.4 g (degree of conversion 36%) of polymer are obtained which has a [ _<( ] value of 4.04 (which is a very indicates high molecular weight) and has no acetate end groups.

Example 2

The moist catalyst (1 g with a water content of 0.3 g) is mixed with 30 ml (26.6 g) of THF. decanted the THF and fresh THF (50 ml; 44.4 g) and 2.16 g (2 ml) acetic anhydride are added to the catalyst. The mixture is stirred for 4 hours. The amount of acetic anhydride used is greater than that required to combine with all the available water to acetic acid is required.

The catalyst is then filtered off from the reaction mass and the solvent is stripped off in vacuo and dry the product at 90 ° C / 50 mm Hg; 12.5 g (degree of conversion 30%) of polymer are obtained a ['J value of 0.30 (Sample 1).

Under analogous conditions, but using dry catalyst and in the absence of Water, there will be a 38% conversion of the THF to a polymer with an [i,] value within 2 hours of 0.78 (sample 2) was achieved. The results can be seen from the comparison below:

Ü Sample catalyst *) THF acetic acid duration PTMEG conversion [,,]

f No. anhydride degree of efficiency

g g g hours g%

1 0.7 44.4 2.16 4 12.5 30 0.30

S5 2 0.84 72 2.1 2 27 38 0.78

*) Dry weight.

Example 3

A series of separate, discontinuous experiments is carried out, the weight ratio of acetic anhydride to acetic acid being varied from 9: 1 to 1: 9. For this purpose, 3 g of catalyst are added to a reaction vessel, 70 ml (62 g) of a THF solution of various proportions of acetic anhydride and acetic acid are added, and the reaction mass is stirred for the specified time at 22 ^° C.

From time to time samples are taken to determine the percentage conversion of the molecular weight. The results (samples 3 to 9) can be seen from the comparison below.

The experiments show that the molecular weight is a function of the acetic anhydride / acetic acid weight ratio and the duration can be.

Sample no

THF

55.8 55.8 55.8 55.8 55.8 55.8 55.8

acetic acid
anhydride
G acetic acid
G Weight
relationship
Anhydride/
acid 1 duration
Hours. Conversion
degree of efficiency
% Mn 3.1 3.1 1 1 1.5 37 1528 3.1 3.1 1 1 5.5 60 1488 3.1 3.1 1 1 21 61 1397 5.6 0.6 9 1 1.5 47 2808 5.6 0.6 9 1 5.5 74 1270 5.6 0.6 9 9 21 82 1002 0.6 5.6 1 1 4 21 23 2304 Example

Rehearse-
No. Weight
relationship
Anhydride/
acid duration
Hours. : Conversion
degree of efficiency
% 10 5.8: 1 3 58 11th 5.8: 1 8th 78 12th 5.8: 1 24 83

20 25 30

A batchwise polymerization of THF analogously to Example 3 is stirred through, 1 g of catalyst being added with 0.36.i; Trifluoroacetic acid and 21 ml (18.7 g) of a THF solution containing 10% acetic anhydride were used. The following results are obtained (samples 10 to 12):

40

The polymers obtained are viscous oils which have both acetate and trifluoroacetate end groups exhibit. ■

Example 5

A mixture of 75.5 g of THF, 3.1 g of propionic anhydride and 1 g of catalyst is stirred for 4 hours.
The catalyst is then filtered off and the unreacted THF is distilled off in vacuo; this gives 24.1 g (degree of conversion 33.5%) of polymer with propionate end groups.

Example 6

A mixture of 75.5 g of THF, 4.2 g of formic acid / acetic anhydride and 1 g of catalyst is stirred. 2V ₂ hours.

The catalyst is then filtered off and the unreacted THF is distilled off in vacuo; man receives 16.3 g (degree of conversion 23%) of polymer with a [//] value of 0.33.

Example 7

A mixture of 72 g of THF, 5 g of propionic anhydride, 3 g of acetic acid and 1 g of catalyst is stirred for 6 hours. The catalyst is filtered off from the mixture and analyzed. Nuclear magnetic resonance spectroscopy shows

60

that 19% of the THF was converted to a polymer with propionate and aciate end groups (ratio 3: 2) and a number average molecular weight (Mn) of 1500.

Example 8

A mixture of 2 g of catalyst, 100 g of THF, 10 g of PTMEG with an Mn of 650 and 6 g of acetic anhydride is stirred at 25 ° C. for 4 hours. The catalyst is then filtered off from the mixture. The unreacted monomer is distilled off in vacuo. The polymer yield is 42 g and the molecular weight of the PTMEG diacetate is 2000.

Example 9

A 1 g sample of catalyst dried according to Example 1 is added to a monomer mixture of 80 g of THF and 20 g 3-methyltetrahydrofuran (3 MeTHF) incorporated. A mixture of 9 g of acetic anhydride is then used and 1 g of acetic acid are added and the batch is stirred at 22 ° C. for 4 hours. The polymerization is then stopped, by filtering off the catalyst from the colorless, viscous polymer solution. Then you distill that unreacted monomers from the reaction mass in vacuo. The polymer product is made with water extracted and dried at 80 ° C / 2 mm Hg to constant weight.

Degree of conversion to diacetate copolymer: 56%

Yield of pure copolymers (based on m

the total polymer): 94% I.

Mn 3130

Composition of the copolymer: 11 mol% 3 MeTHF units

89 mole percent THF units

Example 10

A 1 g sample of catalyst dried according to Example 1 is added to a monomer mixture of 40 g THF and 10 g 2-methyltetrahydrofuran (2 MeTHF) incorporated. Then you add a mixture of 4.5 g of acetic anhydride and 0.5 g of acetic acid are added and the batch is stirred for 5 hours. The polymerization is then stopped by , the catalyst is filtered off from the colorless, viscous polymer solution. Then the unreacted is distilled Polymers in a vacuum from the reaction mass. The polymer product is washed out with water and dried according to Example 9.

Degree of conversion to diacetate copolymer: 44%
Yield of pure copolymers (based on
all polymer): 89%

Mn 1800

Composition of the copolymer: 6.5% 2 MeTHF units

93.2% THF units

Example 11 j? ₍

In this example, a vertical tubular reactor with a volume of 50 ml and a fj

Inside diameter of 25 mm, the sieve packs (clear mesh size 0.120 mm made of rustproof Has steel for the purpose of holding back the catalyst. Furthermore, the reactor is equipped with valves and pipes equipped, with the help of which the reaction components are fed in underneath the bottom sieve pack and the (unreacted) reaction components and products drawn off above the uppermost sieve pack will. The reactor is located in a bath kept at a constant temperature.

A starting material of 90% THF, 9% acetic anhydride and 1% acetic acid is used. In the reactor chamber 5 g of catalyst dried according to Example 1 are initially introduced. The supply of the reaction components and the discharge of the product are carried out at such a speed that a regulated residence time is achieved.

With a residence time of 190 minutes, a THF / PTMEA degree of conversion of 49% is achieved. The product has an Mn of 1500 to 2000. With a contact time of 425 minutes, the degree of conversion is 74%, while the polymer has an Mn of 900 to 1200. Experiments carried out in the same reactor with the same starting material with a residence time of 43 minutes give a THF degree of conversion of 39% and a productivity of 5 g PTMEA / g catalyst / hour.

Either the upflow or the downflow method can be used in the same system.

Example 12

A back-mixing slurry reactor is used in this example with a capacity of 100 ml.

The reactor is operated with a liquid volume of 50 ml. The reaction mixture is with the help stirred with a magnetic stirrer. The reactor is located in a bath kept at a constant temperature

Using an initial charge of 1 g of catalyst (dried according to Example IJ and one
Starting material containing 3.5% acetic anhydride and 1.5% acetic acid in THF, the reactor is operated at 42 ° C. The residence time is 52 minutes. After the steady state has been reached, it is found that a polymer (degree of conversion 21%) with an Mn of 2000 to 2200 has formed. The productivity of this system is 11.1 g PTMA / g catalyst / hour.

An analogous experiment carried out under the same operating conditions but in a tubular reactor yields 9 g PTMEA / g catalyst / hour. The PTMEA has an Mn of 4800.

11th

Claims (2)

Patent claims: 1. A process for the preparation of an ester-terminated poly (tetramethylenäiher) -g! Ykols by polymerization of tetrahydrofuran or an alkyl-substituted tetrahydrofuran, characterized 5 in that the polymerization is conducted in the range vcnO to 120 ⁰ C in a reaction medium, the following Components contains: I (A) an acylium ion precursor in at least an initial concentration of 0.1 to 15 mol%, bczo- | on the reaction mass, 10 (B) a catalytically effective amount of a catalyst in the form of a polymer of ethylenically unsaturated Monomers, the polymer (1) Contains groups of the following general formulas ¹⁵ FZ I I - C - D or —C —D SO ₃ HR X-C-Y
SO ₃ H in which denotes the polymer chain or a segment thereof, D is a hydrogen atom, an aliphatic or aromatic hydrocarbon radical with 30 represents 1 to 10 carbon atoms, a halogen atom or a segment of the polymer chain represents, X and Y each represent a hydrogen atom, a halogen atom, especially a fluorine atom, an iodine atom aliphatic or aromatic hydrocarbon radical with 1 to 10 carbon atoms mean, but at least one of the radicals X and Y must be a fluorine atom, 35 R is a linear or branched linking radical with up to 40 carbon atoms in the main chain represents and Z represents a hydrogen atom, a halogen atom (especially a fluorine atom) or an alipha table or aromatic hydrocarbon radical with 1 to 10 carbon atoms means as well (2) is practically free of functional groups that interfere with the reaction, and, if applicable, g '45 (C) an aliphatic carboxylic acid having 1 to 36 carbon atoms in a concentration of 0.1 to 10% by weight, based on the tetrahydrofuran, with a weight ratio of acylium ion precursors : Acid from 20: 1 to 0.1: 1. 2. The method according to claim 1, characterized in that the acylium ion precursor is acetic an-50 hydride and, as a catalyst, a hydrolyzed copolymer of tetrafluoroethylene or chlorotrifluoroethylene used with a monomer of the general formula below CF ₂ = C- CF _: 0-CF ₂ -C -0-CF ₂ -CF ₂ -SO ₂ F Ibis IO where the weight ratio of the tetrafluoroethylene or chlorotrifluoroethylene units to the units of the other monomer (50 to 75): (25 to 50). Poly (tetramethylene ether) glycol (PTMEG) is used on a large scale in the manufacture of polyurethanes and polyesters are used. It is made by reacting tetrahydrofuran (THF) with fluorosullonic acid and 65 Quenching the reaction product obtained with water. Although this synthetic procedure has proven to be quite satisfactory, it does not show what it is intended to be Efficiency because the acid cannot be recovered and reused. Further the disposal of the used acid is problematic due to its toxicity and corrosive effect. It has now been found that esters of PTMEG can be prepared by adding TH F in a reaction mixture polymerized, which in addition to TI IF an acylium ion precursor and a polymerization catalyst contains. Although the catalyst is more complicated in nature, it can be broadly classified as -fluorosulfonic acid groups containing polymer. The esters mentioned can be obtained by alcoholysis in an alkaline medium using an oxide, hydroxide or alkoxide of calcium, Strontium, barium or magnesium can be converted into PTMEG as a catalyst. In the first stage of the process, the nature of the catalyst allows it to be reused, thereby the elimination problem is solved, and the low solubility of the catalyst in the reaction mass enables the product to be easily separated off from the catalyst after the reaction. Based on these If the solubility is poor, the loss of catalyst which occurs in the course of the reaction will also be kept to a minimum degraded. According to the invention, the THF, an acylium ion precursor, the catalyst and optionally a carboxylic acid is brought together under conditions suitable for polymerization.