METHOD FOR PRODUCING A POLYOXYALKYLENE POLYESTER POLYOL

Abstract

The invention relates to a method for producing a polyoxyalkylene polyester polyol by reacting a polyoxyalkylene polyol with a lactone in the presence of a Brønsted acid catalyst, wherein the catalyst has a pKa value of 1 or less; the number-average molar mass of the polyoxyalkylene polyol is ≥1000 g/mol, preferably ≥1500 g/mol, particularly preferably ≥2000 g/mol; and in the lactone a CH2 group is bonded to the ring oxygen. The invention further relates to polyoxyalkylene polyester polyols obtainable using the method according to the invention, and to a method for producing polyurethanes by reacting the polyoxyalkylene polyester polyols according to the invention with polyisocyanates.

Claims

1. A process for preparing a polyoxyalkylene polyester polyol comprising reacting a polyoxyalkylene polyol with a lactone in the presence of a Brønsted-acidic catalyst; wherein the catalyst has a pKa of 1 or less; wherein the number-average molar mass of the polyoxyalkylene polyol is >1000 g/mol; and wherein in the lactone a CH.sub.2 group is bonded to the ring oxygen.

2. The process as claimed in claim 1, wherein the lactone comprises beta-propiolactone, gamma-butyrolactone, delta-valerolactone, and epsilon-caprolactone, or a mixture thereof.

3. The process as claimed in claim 1, wherein the molar ratio of lactone to the hydroxyl end groups of the polyoxyalkylene polyol is 1:1 to 20:1.

4. The process as claimed in claim 1, wherein the Brønsted-acidic catalyst comprises trifluoromethanesulfonic acid, perchloric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, methanesulfonic acid, trichloroacetic acid, trifluoroacetic acid, or a mixture thereof.

5. The process as claimed in claim 1, wherein the Brønsted-acidic catalyst is used in an amount of 0.001 mol % to 0.5 mol %, based on the amount of lactone.

6. The process as claimed in claim 1, wherein the polyoxyalkylene polyol has a proportion of secondary OH end groups of at least 75%, based on the sum total of primary and secondary OH end groups, as determined by means of .sup.1H NMR spectroscopy.

7. The process as claimed in claim 1, wherein the polyoxyalkylene polyol comprises a polyether polyol and/or polyether carbonate polyol.

8. The process as claimed in claim 7, wherein the polyoxyalkylene polyol comprises a polyether polyol prepared by reaction of an H-functional starter substance with alkylene oxide in the presence of a double metal cyanide catalyst.

9. The process as claimed in claim 7, wherein the polyoxyalkylene polyol comprises a polyether carbonate polyol prepared by reaction of an H-functional starter substance with alkylene oxide and carbon dioxide in the presence of a double metal cyanide catalyst.

10. The process as claimed in claim 8, wherein the alkylene oxide is ethylene oxide and/or propylene oxide.

11. The process as claimed in claim 10, wherein the proportion by weight of propylene oxide is 80% by weight to 100% by weight based on the sum total of the masses of propylene oxide and of ethylene oxide metered in.

12. The process as claimed in claim 1, wherein the process is performed without addition of a solvent.

13. A polyoxyalkylene polyester polyol obtained by the process of claim 1, wherein the polyoxyalkylene polyester polyol has a proportion of primary OH end groups of at least 80%, based on the sum total of primary and secondary OH end groups, wherein the primary OH end groups is determined by means of .sup.1H or .sup.13C NMR spectroscopy.

14. The polyoxyalkylene polyester polyol, as claimed in claim 13, wherein the polyoxyalkylene polyester polyol has a polydispersity index of ≤1.20 as determined by means of gel permeation chromatography.

15. A process for preparing a polyurethane comprising reacting the polyoxyalkylene polyester polyol as claimed in claim 13 with a polyisocyanate.

Description

EXAMPLES

[0143] The present invention is elucidated in more detail by the figures and examples which follow, but without being limited thereto.

[0144] Starting materials used

[0145] Cyclic lactones

[0146] β-Propiolactone (purity<98%, Acros Organics BVBA)

[0147] ε-Caprolactone (purity<97%, Sigma-Aldrich)

[0148] Catalysts

[0149] Trifluoromethanesulfonic acid (purity<99%, Acros Organics)

[0150] DMC catalyst prepared in accordance with example 6 of WO 01/80994 A1

[0151] Tin(II) 2-ethylhexanoate (purity 92.5-100%, Sigma-Aldrich)

[0152] Polyoxyalkylene Polyol (Polyether Polyol)

[0153] Polyether polyol A was prepared using DMC catalysis as follows:

[0154] A 20 I pressure reactor was initially charged under nitrogen with 1739.3 g of a poly(oxypropylene) triol having an OH number of 233 mg KOH/g and 0.367 g of DMC catalyst (prepared in accordance with example 6 of WO 01/80994 A1). The reactor was heated to 130° C., inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. A mixture of 9256 g of propylene oxide and 1028 g of ethylene oxide was then metered in at 130° C. within three hours. After post-reaction time at 130° C. to constant pressure in the reactor, volatile constituents were distilled off under reduced pressure at 90° C. for 30 min and then the reaction mixture was cooled to room temperature. The OH number of the product was 34.3 mg KOH/g, the number-average molecular weight M.sub.n was 6665 g/mol, the polydispersity was 1.03 and the proportion of primary hydroxyl end groups was 18%.

[0155] Description of the methods:

[0156] Gel Permeation Chromatography (GPC):

[0157] The number-average molecular weight M.sub.n and the weight-average molecular weight M.sub.w, and also the polydispersity (M.sub.w/M.sub.n), of the products were determined by means of gel permeation chromatography (GPC). The procedure of DIN 55672-1 was followed: “Gel permeation chromatography, Part 1—Tetrahydrofuran as eluent” (SECurity GPC System from PSS Polymer Service, flow rate 1.0 ml/min; columns: 2×PSS SDV linear M, 8×300 mm, 5 μm; RID detector). Polystyrene samples of known molar mass were used for calibration.

[0158] .sup.1H and .sup.13C NMR Spectroscopy

[0159] Determination of the molar proportion of primary OH groups: by means of .sup.1H (Bruker AV III HD 600, 600 MHz, deuterochloroform) or .sup.13C NMR (Bruker AV III HD 600, 151 MHz, deuterochloroform):

[0160] To determine the content of primary OH groups, the polyol samples were first peracetylated. This was done using the following peracetylation mixture: [0161] 9.4 g of acetic anhydride p.a.

[0162] 1.6 g of acetic acid p.a. [0163] 100 ml of pyridine p.a.

[0164] For the peracetylation reaction, 10 g of polyol (polyoxyalkylene polyol or polyoxyalkylene polyester polyol) were weighed into a 300 ml flanged Erlenmeyer flask. The volume of peracetylation mixture was guided by the OH number of the polyol to be peracetylated, rounding the OH number of the polyol up to the next multiple of 10 (based in each case on 10 g of polyol); for every 10 mg KOH/g, 10 ml of peracetylation mixture are then added. For example, 50 ml of peracetylation mixture were correspondingly added to the sample of 10 g of a polyol having an OH number of 45.1 mg KOH/g.

[0165] After the addition of glass boiling chips, the flanged Erlenmeyer flask was provided with a riser tube (air cooler) and the sample was boiled under gentle reflux for 75 min. The sample mixture was then transferred into a 500 ml round-bottom flask, and volatile constituents (essentially pyridine, acetic acid and excess acetic anhydride) were distilled off at 80° C. and 10 mbar (absolute) over a period of 30 min. The distillation residue was then admixed three times with 100 ml each time of cyclohexane (toluene was used as an alternative in the cases in which the distillation residue did not dissolve in cyclohexane), and volatile constituents of the sample were removed at 100° C. and 10 mbar (absolute) for one hour.

[0166] For the determination of the molar proportions of primary and secondary OH end groups in the polyol, the sample thus prepared was dissolved in deuterated chloroform and analyzed using .sup.1H NMR (Bruker AV III HD 600, 600 MHz) or .sup.13C NMR (Bruker AV III HD 600, 151 MHz). The relevant resonances in the .sup.1H NMR (based on TMS=0 ppm) are as follows:

[0167] Methyl signal of a peracetylated secondary OH end group: 2.04 ppm

[0168] Methyl signal of a peracetylated primary OH end group: 2.07 ppm

[0169] The molar proportion of secondary and primary OH end groups is then found as follows:

[0170] Proportion of secondary OH end groups (CH—OH)=F(2.04)/(F(2.04)+F(2.07))*100% (VII)

[0171] Proportion of primary OH end groups (CH.sub.2—OH)=F(2.07)/(F(2.04)+F(2.07))*100% (VIII)

[0172] In the formulae (VII) and (VIII), F represents the area of the resonance at 2.04 ppm or 2.07 ppm, respectively.

[0173] The relevant resonances in the .sup.13C NMR (based on TMS=0 ppm) are as follows:

[0174] Methyl signal of a peracetylated secondary OH end group: 21.3 ppm

[0175] Methyl signal of a peracetylated primary OH end group: 20.8 ppm

[0176] The molar proportion of secondary and primary OH end groups is then found as follows:

[0177] Proportion of secondary OH end groups (CH—OH)=F(21.3)/(F(21.3)+F(20.8))*100% (IX)

[0178] Proportion of primary OH end groups (CH.sub.2—OH)=F(20.8)/(F(21.3)+F(20.8))*100% (X)

[0179] In the formulae (IX) and (X), F represents the area of the resonance at 21.3 ppm or 20.8 ppm, respectively.

[0180] Infrared Spectroscopy

[0181] The percentage lactone conversion, based on the amount of lactone used, was determined by means of IR spectroscopy. To this end, the product carbonyl band was analyzed (1740 cm.sup.−1). The reference used was in each case the product carbonyl band of a sample having the same molar lactone/hydroxyl end group ratio and for which no characteristic lactone reactant bands (e.g. beta-propiolactone reactant carbonyl bands 1802 cm.sup.−1, 1824 cm.sup.−1) were observed and the lactone conversion of which was therefore set to 100%.

[0182] The percentage lactone conversion is then as follows:

X(lactone)[%]=F(1740)/F.sub.ref(1740)*100%  (XI)

[0183] In formula (XI), F is the area of the product carbonyl band at 1740 cm.sup.−1 and F.sub.ref is the area of the product carbonyl band at 1740 cm.sup.−1 of a reference sample having the same lactone/hydroxyl end group ratio and complete lactone conversion.

[0184] OH Numbers OH numbers were determined according to the method of DIN 53240.

Example 1

[0185] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.03 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 5.9 g) at intervals of 15 minutes (total amount of beta-propiolactone: 15.9 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 2/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 80% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 7424 g/mol, the polydispersity is 1.11 and the proportion of primary hydroxyl end groups is 85%.

Example 2

[0186] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.04 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.2 g) at intervals of 15 minutes (total amount of beta-propiolactone: 26.2 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 3.3/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 95% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 7782 g/mol, the polydispersity is 1.10 and the proportion of primary hydroxyl end groups is 89%.

Example 3

[0187] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.7 g) at intervals of 15 minutes (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 8071 g/mol, the polydispersity is 1.11 and the proportion of primary hydroxyl end groups is 96%.

Example 4

[0188] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.7 g) at intervals of 1 hour (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 8083 g/mol, the polydispersity is 1.10 and the proportion of primary hydroxyl end groups is 82%.

Example 5

[0189] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.17 g of trifluoromethanesulfonic acid (0.25 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.7 g) at intervals of 1 hour (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 7696 g/mol, the polydispersity is 1.05 and the proportion of primary hydroxyl end groups is 93%.

Example 6

[0190] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 100° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 100° C., a mixture of 10 g of the polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 100° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.7 g) at intervals of 15 min (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 100° C. and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 8374 g/mol, the polydispersity is 1.14 and the proportion of primary hydroxyl end groups is 85%.

Example 7

[0191] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was first added and then 31.7 g of beta-propiolactone were added (corresponding to the total amount of beta-propiolactone; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). The reaction mixture was stirred at 60° C. for 2 hours and then cooled to room temperature. A lactone conversion of 94% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 8133 g/mol, the polydispersity is 1.10 and the proportion of primary hydroxyl end groups is 85%.

Example 8:

[0192] A 500-ml three-neck round-bottomed flask was initially charged with 180 g of the polyether polyol A, this was heated to 60° C., and 0.05 g of trifluoromethanesulfonic acid (0.08 mol % based on the total amount of the lactone used) was added. 31.7 g of beta-propiolactone (corresponding to the total amount of beta-propiolactone; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1) were then added continuously over a period of 45 min. After lactone addition was complete, the reaction mixture was stirred for 75 min at 60° C. and then cooled to room temperature. A lactone conversion of 97% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 8113 g/mol, the polydispersity is 1.11 and the proportion of primary hydroxyl end groups is 80%.

Example 9 (Comparative Example)

[0193] A 2-liter stainless steel reactor was initially charged with 200 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 100° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). 5 g of beta-propiolactone were added and the reaction mixture was stirred at 100° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 5.3 g) at intervals of 15 min (total amount of beta-propiolactone: 35.3 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 100° C. and then cooled to room temperature. A lactone conversion of 4% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 6721 g/mol, the polydispersity is 1.03 and the proportion of primary hydroxyl end groups is 31%.

Example 10 (Comparative Example)

[0194] A 2-liter stainless steel reactor was initially charged with 200 g of the polyether polyol A and 0.18 g of DMC catalyst (prepared in accordance with example 6 in WO 01/80994 A1) and this mixture was heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 100° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). 5 g of beta-propiolactone were added and the reaction mixture was stirred at 100° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 5.3 g) at intervals of 15 min (total amount of beta-propiolactone: 35.3 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 100° C. and then cooled to room temperature. A lactone conversion of 5% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 6666 g/mol, the polydispersity is 1.02 and the proportion of primary hydroxyl end groups is 28%.

Example 11 (Comparative Example)

[0195] A 2-liter stainless steel reactor was initially charged with 170 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.14 g of tin(II) 2-ethylhexanoate (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of beta-propiolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. beta-Propiolactone was then added in portions of 5 g (last portion: 6.7 g) at intervals of 15 minutes (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 2% was determined by IR spectroscopy. The number-average molecular weight M of the product is 6675 g/mol, the polydispersity is 1.07 and the proportion of primary hydroxyl end groups is 12%.

Example 12 (Comparative Example)

[0196] A 2-liter stainless steel reactor was initially charged with 190 g of the polyether polyol A and heated to 130° C. The reactor was inertized by three times evacuating to 100 mbar (absolute) and repeated charging with nitrogen, and then stripping was performed for 30 min at 100 mbar and 130° C. with the passage of nitrogen through the reactor. The reactor was then cooled to 60° C. and nitrogen was used to establish a reactor pressure of 1 bar (absolute). At 60° C., a mixture of 10 g of the polyether polyol A and 0.16 g of tin(II) 2-ethylhexanoate (0.08 mol % based on the total amount of the lactone used) was first added and then 5 g of epsilon-caprolactone were added. The reaction mixture was stirred at 60° C. for 2 hours. epsilon-Caprolactone was then added in portions of 5 g (last portion: 5.8 g) at intervals of 15 minutes (total amount of epsilon-caprolactone: 55.8 g; molar ratio of lactone/hydroxyl end groups of the polyether polyol A: 4/1). After lactone addition was complete, the reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. A lactone conversion of 0% was determined by IR spectroscopy. The number-average molecular weight M.sub.n of the product is 6675 g/mol, the polydispersity is 1.06 and the proportion of primary hydroxyl end groups is 13%.

TABLE-US-00001 TABLE 1 Comparison of experiments 1 to 12. Addition x(cat) Experiment of lactone.sup.a) Lactone.sup.b) Polyoxyalkylene polyol Catalyst.sup.c) [mol %].sup.d) 1 sw PL Polyether polyol A TfOH 0.08 2 sw PL Polyether polyol A TfOH 0.08 3 sw PL Polyether polyol A TfOH 0.08 4 sw PL Polyether polyol A TfOH 0.08 5 sw PL Polyether polyol A TfOH 0.25 6 sw PL Polyether polyol A TfOH 0.08 7 batch PL Polyether polyol A TfOH 0.08 8 cont. PL Polyether polyol A TfOH 0.08 9 (comp.) sw PL Polyether polyol A DMC.sub.act — 10 (comp.) sw PL Polyether polyol A DMC.sub.act + — DMC.sub.fresh 11 (comp.) sw PL Polyether polyol A Sn cat. 0.08 12 (comp.) sw CL Polyether polyol A Sn cat. 0.08 Lactone/hydroxyl end groups of the Primary OH polyoxy-alkylene T X(lactone) end groups M.sub.n Experiment polyol [mol/mol] [° C.] [%] [%] [g/mol] PDI 1 2/1 60 80 85 7424 1.11 2 3.3/1   60 95 89 7782 1.10 3 4/1 60 100 96 8071 1.11 4 4/1 60 100 82 8083 1.10 5 4/1 60 100 93 7696 1.05 6 4/1 100 100 85 8374 1.14 7 4/1 60 94 85 8133 1.10 8 4/1 60 97 80 8113 1.11 9 (comp.) 4/1 100 4 31 6721 1.03 10 (comp.) 4/1 100 5 28 6666 1.02 11 (comp.) 4/1 60 2 12 6775 1.07 12 (comp.) 4/1 60 0 13 6776 1.06 .sup.a)Lactone addition: semi-batch mode with stepwise lactone addition (sw); batch mode (batch); semi-batch mode with continuous lactone addition (cont.) .sup.b)beta-Propiolactone (PL), epsilon-caprolactone (CL) .sup.c)Trifluoromethanesulfonic acid (TfOH); DMC catalyst present from the preparation of the polyether polyol A (DMC.sub.act); DMC catalyst added to the polyether polyol A (DMC.sub.fresh); tin(II) 2-ethylhexanoate (Sn cat.) .sup.d)Based on the amount of lactone used