POLYALKYLENE OXIDE ESTER POLYMER, ITS PREPARATION AND USE

Abstract

Disclosed herein is a polyalkylene oxide ester polymer with a weight average molecular weight Mw in the range of from 500 to 50,000 g/mol and a polydispersity PD in the range of from 2 to 6, including 10 to 560 ether groups and 2 to 51 ester groups that are interconnected with alkylene groups, which are significantly more biodegradable than conventional polyalkylene oxide polymers. Further disclosed herein are a method of preparing a polyalkylene oxide ester polymer and a method of using the polyalkylene oxide ester polymer.

Claims

1. A polyalkylene oxide ester polymer with a weight average molecular weight Mw in the range of from 500 to 50,000 g/mol and a polydispersity PD in the range of from 2 to 6, comprising 10 to 560 ether groups and 2 to 51 ester groups, which are interconnected with alkylene groups, wherein the polyalkylene oxide ester polymer contains A) 1 to 51 structural elements of the general formula (I) ##STR00029## wherein the O unit at the left side is bound to a CO unit of an adjacent unit of the polymer, forming an ester unit, the CO unit at the right side is bound to a O unit of an adjacent unit of the polymer, forming a further ester unit, R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 represent independent of each other a hydrogen atom or a C.sub.1-12 alkyl group, a, b, c, d, and e represent independent of each other an integer of 0 or 1, whereas the sum of a, b, c, d, and e is 1 to 5, and X represents a polyalkylene oxide unit with 4 to 100 alkylene oxide units, whereby wherein the alkylene oxide units contain independent of each other 2 to 6 carbon atoms in the direct chain between two O units, wherein each of the carbon atoms in the direct chain between two O units contains independent of each other either two hydrogen atoms, or one hydrogen atom and one C.sub.1-12 alkyl group, B) 1 to 25 structural elements of the general formula (II) ##STR00030## wherein the CO unit at the left side is bound to a O unit of an adjacent unit of the polymer, forming an ester unit, the CO unit at the right side is bound to a O unit of an adjacent unit of the polymer, forming a further ester unit, R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.13, R.sup.14, R.sup.15, R.sup.16, and R.sup.17 represent independently of each other a hydrogen atom or a C.sub.1-12 alkyl group, g, h, i, j, k, m, n, o, p, and q represent independent of each other an integer of 0 or 1, whereas the sum of g, h, i, i, and k is 1 to 5, and the sum of m, n, o, p, and a is 1 to 5, and Y represents a polyalkylene oxide unit with 0 to 99 alkylene oxide units, whereby wherein the alkylene oxide units contain independent of each other 2 to 6 carbon atoms in the direct chain between two ether groups, wherein each of the carbon atoms in the direct chain between two ether groups contains independent of each other either two hydrogen atoms, or one hydrogen atom and one C.sub.1-12 alkyl group, and C) polyalkylene oxide units of the general formula (III) in a number suitable to form ester bonds with the CO units of the structural elements of the formulas (I) and (II) ##STR00031## wherein the O unit at the left side is bound to a CO unit of an adjacent unit of the polymer, forming an ester unit, the O unit at the right side is bound to a CO unit of an adjacent unit of the polymer, forming a further ester unit, R.sup.19, R.sup.20, R.sup.21, R.sup.22, R.sup.23, and R.sup.24 represent independently of each other a hydrogen atom or a C.sub.1-12 alkyl group, s, t, u, v, w, and x represent independent of each other an integer of 0 or 1, whereas the sum of s, t, u, v, w, and x is 2 to 6, and Z represents a polyalkylene oxide unit with 0 to 100 alkylene oxide units, whereby wherein the alkylene oxide units are independent of each other and contain 2 to 6 carbon atoms in the direct chain between two ether groups, wherein each of the carbon atoms in the direct chain between two ether groups contains independent of each other either two hydrogen atoms, or one hydrogen atom and one C.sub.1-12 alkyl group, with the proviso that the total number of the ester groups does not exceed the maximum number of the ester groups specified for the polyalkylene oxide ester polymer.

2. A polyalkylene oxide ester polymer according to claim 1, wherein R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 and R.sup.3 represent a hydrogen atom, d and e are 0, a is 1, b and c represent an integer of 0 or 1, whereas wherein the sum of b to c is 0 or 2, and X represents a polyalkylene oxide unit with 4 to 100 alkylene oxide units, whereby wherein the alkylene oxide units are independent of each other and contain 2 or 4 carbon atoms in the direct chain between two ether groups, wherein in each alkylene oxide unit, and independent of each other, one of the carbon atoms in ?-position to an O unit contains either two hydrogen atoms, or one hydrogen atom and one methyl group, and the other one or three carbon atoms contain two hydrogen atoms each, wherein each O unit carries not more than one methyl group carrying carbon atom in ?-position.

3. A polyalkylene oxide ester polymer according to claim 1, wherein R.sup.1 represents a hydrogen atom or a methyl group, b, c, d, and e are 0, a is 1, and X represents a polyalkylene oxide unit with 4 to 100 alkylene oxide units, wherein the alkylene oxide units are independent of each other and contain 2 carbon atoms in the direct chain between two ether groups, wherein in each alkylene oxide unit, and independent of each other, one of the carbon atoms in ?-position to an O unit contains either two hydrogen atoms, or one hydrogen atom and one methyl group, and the other carbon atom contains two hydrogen atoms, wherein each O unit carries not more than one methyl group carrying carbon atom in ?-position.

4. A polyalkylene oxide ester polymer according to claim 1, wherein R.sup.13 and R.sup.19 represent independent of each other a hydrogen atom or a methyl group, R.sup.9, R.sup.10, R.sup.11, R.sup.14, R.sup.15, R.sup.20, R.sup.21, and R.sup.24 represent a hydrogen atom, g, h, p, q, v, and w are 0, k, m, s, and x are 1, i, j, n, o, t, and u represent independent of each other an integer of 0 or 1, whereas the sum of i to j is 0 or 2, the sum of n to o is 0 or 2, and the sum of t to u is 0 or 2, and Y represents a polyalkylene oxide unit with 3 to 99 alkylene oxide units, and Z represents a polyalkylene oxide unit with 4 to 100 alkylene oxide units, wherein the alkylene oxide units are independent of each other and contain 2 or 4 carbon atoms in the direct chain between two ether groups, wherein in each alkylene oxide unit, and independent of each other, one of the carbon atoms in ?-position to an O unit contains either two hydrogen atoms, or one hydrogen atom and one methyl group, and the remaining other one or three carbon atoms contain two hydrogen atoms each, wherein each O unit carries not more than one methyl group carrying carbon atom in ?-position.

5. A polyalkylene oxide ester polymer according to claim 1, wherein R.sup.13 and R.sup.19 represent independent of each other a hydrogen atom or a methyl group, R.sup.9, R.sup.10, R.sup.11, R.sup.14, R.sup.15, R.sup.20, R.sup.21, and R.sup.24 represent a hydrogen atom, g, h, i, j, n, o, p, q, t, u, v, and w are 0, k, m, s, and x are 1, and Y represents a polyalkylene oxide unit with 3 to 99 alkylene oxide units, and Z represents a polyalkylene oxide unit with 4 to 100 alkylene oxide units, wherein the alkylene oxide units are independent of each other and contain 2 carbon atoms in the direct chain between two ether groups, wherein in each alkylene oxide unit, and independent of each other, one of the carbon atoms in ?-position to an O unit contains either two hydrogen atoms, or one hydrogen atom and one methyl group, and the remaining other carbon atom contains two hydrogen atoms, wherein each O unit carries not more than one methyl group carrying carbon atom in ?-position.

6. A polyalkylene oxide ester polymer according to claim 1, wherein the ratio of the number of ether groups to the number of ester groups is 4 to 100.

7. A polyalkylene oxide ester polymer according to claim 1, wherein the ratio of the number of the structural elements (I) to the number of the structural elements (II) is 0.5 to 8.

8. A polyalkylene oxide ester polymer according to claim 1, wherein the structural elements (I), (II) and (III) constitute 80 to 100% of the molecular weight of the polyalkylene oxide ester polymer.

9. A process for preparing a polyalkylene oxide ester polymer according to claim 1, which comprises esterifying a mixture comprising a) a polyalkylene oxide comprising the structural element (I) and having one primary OH and one COOH end group, or a mixture of such polyalkylene oxides, b) a polyalkylene oxide comprising the structural element (II) and having two COOH end groups, or a mixture of such polyalkylene oxides, and c) a polyalkylene oxide comprising the structural element (III) and having two primary OH end groups, or a mixture of such polyalkylene oxides, at a temperature of 50 to 250? C. and a pressure of 0.1 kPa abs to 1 MPa abs in the presence of an esterification catalyst.

10. The process according to claim 9, wherein the ratio of the number of the OH end groups to the number of the COOH end groups is 0.9 to 1.1.

11. The process according to claim 9, wherein the mixture of the components a) to c) is produced by partial oxidation of the respective polyalkylene oxide having two primary OH end groups, or a mixture of such polyalkylene oxides, with oxygen at a temperature in the range of from 20 to 100? C. and a partial oxygen pressure in the range of from 0.01 to 2 MPa abs in the presence of water and a heterogeneous catalyst comprising platinum, palladium or gold, and the oxidation reaction is stopped after a ratio of the number of the OH end groups to the number of the COOH end groups in the range of from 0.9 to 1.1 has been reached.

12. A method of using the polyalkylene oxide ester polymer according to claim 1, the method comprising using the polyalkylene oxide ester polymer for the encapsulation of fragrances, as building blocks for the preparation of block polymers, or in homecare and laundering applications.

Description

EXAMPLES

Determination of the K-Value

[0302] The K-value is determined by measuring the relative viscosity of dilute polymer solutions and is a relative measure of the average molecular weight. As the average molecular weight of the polymer increases for a particular polymer, the K-value tends to also increase. The K-value of the esterified mixtures were determined in a 3 wt.-% NaCl solution at 23? C. and a polymer concentration of 1 wt.-% polymer according to the method of H. Fikentscher, described in Cellulosechemie, 1932, 13, 58.

Determination of M.sub.n, M.sub.w and PD

[0303] The number average molecular weight M.sub.n, the weight average molecular weight M.sub.w and the polydispersity M.sub.w/M.sub.n of the esterified mixtures were determined by size exclusion chromatography (SEC) in tetrahydrofuran. As mobile phase (eluent), tetrahydrofuran comprising 0.035 mol/L diethanolamine was used. The concentration of the esterified polymers in tetrahydrofuran was 2.0 mg per mL. After filtration (pore size 0.2 ?m), 100 ?L of this solution were injected into a SEC system. Four different columns (heated to 60? C.) were used for separation (SDV precolumn, SDV 1000A, SDV 100 000A, SDV 1 000 000A). The SEC system was operated at a flow rate of 1 mL per min. A DRI Agilent 1100 was used as the detection system. Poly(ethylene glycol) (PEG) standards (PL) having a molecular weight M.sub.n from 106 to 1 378 000 g/mol were used for the calibration.

Description of the OECD 301B Degradation Test

[0304] The biodegradation was tested in waste water in triplicate using the OECD 301B manometric respirometry method. 30 mg/mL test substance is inoculated into waste water taken from the waste water treatment plant of Mannheim (Germany) and incubated in a closed flask at 25? C. for 28 days. The consumption of oxygen during this time is measured as the change in pressure inside the flask using an OxiTop C (WTW). Evolved CO.sub.2 is absorbed using an NaOH solution.

[0305] The amount of oxygen consumed by the microbial population during biodegradation of the test substance, after correction using a blank, is expressed as percentage of the theoretical oxygen demand (ThOD).

Examples 1 to 10

[0306] In examples 1 to 10, polyalkylene oxides with two primary OH end groups (called diol) were oxidized to mixtures containing at least a polyalkylene oxide with two COOH end groups (called diacid) and a polyalkylene oxide with one primary OH and one COOH end group (called monoacid), and, optionally, also remaining polyalkylene oxide with two primary OH end groups. The mixtures were prepared as follows.

[0307] Platinum on charcoal (5.0 wt.-% Pt on C, water content: 59.7 wt.-%, 283 g, 29.2 mmol Pt) was suspended in a mixture of polyalkylene oxide comprising two primary OH end groups (details see table 1) and water (details see table 1), heated to 52? C. and stirred at 800 rpm. Oxygen was passed through the stirred mixture (20 nL/h) via a glass tube, equipped with a glass frit and the temperature was allowed to rise to 60? C. Oxygen dosage and temperature were maintained for the period mentioned in table 1, the oxygen dosage was then stopped and the mixture was allowed to cool down to room temperature. Solids were separated from the liquid phase by filtration and the filter cake was washed with 500 mL of warm water. The washing water was mixed with the filtrate. Water was removed from the liquid mixture by distillation over a wiped film evaporator (overall height: 87.2 cm, diameter: 3.54 cm, wiped height: 43 cm, feed: 4.0 mL/min, 44? C., 1.8 kPa abs, 600 rpm). The sump product from the wiped film evaporator was analyzed. The content of OH-groups determined by determination of the hydroxy number, and the content of COOH-groups determined by determination of the acid number. The conversion of the polyalkylene oxides in the partial oxidation was derived from the acid number.

[0308] For the partially oxidized mixture based on the low molecular polyalkylene oxide with a M.sub.w value of 200 g/mol, the distribution of the diol, monoacid and diacid was determined by gaschromatography. For this, 0.1 g of a dried sample of the partially oxidized polyalkylene oxide was heated with 1 g of N-methyl-N-(trimethylsilyl)trifluoracetamide to 80? C. and kept at this temperature for one hour. The resulting mixture was then analyzed via gaschromatography. For the other mixtures based on polyalkylene oxides with ?400 g/mol, the distribution was calculated from the total content of the OH and COOH-groups assuming that each OH-group, irrespective of whether being part of the diol or part of the mono-acid, is oxidized with the same probability. The respective values are shown in table 1.

Examples 11 to 21 and 22

[0309] Examples 11 to 21 relate to the esterification of the oxidized polyalkylene oxide mixtures obtained by examples 1 to 10 and the determination of the biodegradability of the obtained polyalkylene oxide ester polymers. Example 22 is a comparative example in which the biodegradability of a conventional polyethylene oxide (PEG) was determined.

[0310] In examples 11 to 21, 98 g of a mixture of polyalkylene oxides obtained by the oxidation procedures described in examples 1 to 10, hereinafter referred to as educt mixture (details see table 2a and 2b), and 2 g water were mixed with an esterification catalyst (details see table 2a and 2b) and heated for a period of time mentioned in table 2a and 2b under vacuum at a pressure of 1 kPa abs, whereby the temperature was slowly increased from 125? C. at the beginning to 145? C. at the end.

[0311] The obtained esterified mixture was then analyzed, and the K-value, the number average molar mass M.sub.n and the molecular weight distribution M.sub.w determined as described above. The biodegradability was determined by the OECD 301 B degradation test, which is described above.

[0312] The average numbers of the ester groups and the ether groups in the polyalkylene oxide ester polymer were estimated from the estimated averaged molecular weights of the respective polyalkylene oxide ester polymers and the respective polyalkylene oxides used in the antecedent oxidation step. For the respective polyalkylene oxide ester polymers, the number average molecular weight M.sub.n was used since it is a good measure of the average molecular weight on a molecular scale. Regarding the respective polyalkylene oxides used in the antecedent oxidation step, the molecular average molecular weight M.sub.w could be alternatively used since the polyethylene oxides typically have a low polydispersity PD slightly above 1, so that M.sub.w and M.sub.n only slightly differ.

[0313] The number of the ester groups in the polyalkylene oxide ester polymers, which were based on the use of partially oxidized polyethylene oxides (relating to a ratio of the oxidized OH groups of around 50%), was estimated as follows. First, the number of the structural units was estimated by dividing (1) the number average molecular weight M.sub.n of the polyalkylene oxide ester polymer, which has been corrected by 18 g/mol considering the two end groups, (2) by the average molecular weight of the esterified structural elements. The latter was calculated by the molecular average molecular weight M.sub.w of the used polyethylene oxide minus 18 g/mol, considering that water is split off by the esterification, plus 16 g/mol minus 2 g/mol, considering that in the average arithmetically one CO unit per structural element was formed from the respective CH.sub.2 unit. In case of the structural element of formula (I), it is exactly one per structural element, in case of a combination of structural elements of formula (II) and (III), it is two and zero leading also to one in the average. Second, the number of the structural units was reduced by 1 to consider that each ester group in the polyalkylene oxide ester polymer of the examples connects two structural elements, so that there is one structural element more than ester groups.

[0314] The above-mentioned estimation is specifically explained for example 12. The number average molecular weight M.sub.n of the polyalkylene oxide ester polymer was 2400 g/mol, leading to a value of 2382 g/mol. The average molecular weight of the esterified structural elements was (400-4) g/mol=396 g/mol. This leads to an average number of structural units of 2382/396=6.0 and consequently to an average number of ester groups of 5.0, or expressed in a mathematical equation

[00004]$\frac{\left(2400-18\right)}{\left(400-4\right)}-1=5.0.$

[0315] The number of the ether groups in the polyalkylene oxide ester polymers, which were based on the use of partially oxidized polyethylene oxides (relating to a ratio of the oxidized OH groups of around 50%), was estimated as follows. First, the number of the ethylene oxide units in the used polyethylene oxide was calculated by dividing (1) the molecular average molecular weight M.sub.w of the used polyethylene oxide minus 18 g/mol, considering the end groups formally formed by the addition of one molecule of water per polyethylene oxide molecule during the polymerization, (2) by 44 g/mol which is the molecular weight of a CH.sub.2CH.sub.2O unit. Second, the number of the ethylene oxide units was reduced by 1 to consider that each polyethylene oxide has one ether group less than the number of the ethylene oxide units. The result is the average number of the ether groups in the polyethylene oxide. Third, this number was then multiplied with the number of the structural units in the polyalkylene oxide ester polymers, which was calculated as described above.

[0316] The above-mentioned estimation is specifically explained for example 12. The molecular average molecular weight M.sub.w of the used polyethylene oxide was 400 g/mol leading to a value of 382 g/mol. Its division by 44 g/mol leads to a number of 8.7 CH.sub.2CH.sub.2O units, which at the end lead to an average of 7.7 ether units in the polyethylene oxide. Since the average number of the structural units in the polyalkylene oxide ester polymer was estimated above as 6.0, the average number of the ether groups in the polyalkylene oxide ester polymer was 46, or expressed in a mathematical equation

[00005]$\left[\frac{400-18}{44}-1\right]?\frac{2400-18}{400-4}=46.$

[0317] In the examples which were based on the use of fully oxidized polyethylene oxides (relating to a ratio of the oxidized OH groups of around 95 to 100%) and therefore required the addition of a diol as second component, the number of the ester groups and ether groups was estimated in a similar way as described above with the main difference that the molecular average molecular weight M.sub.w of the used polyethylene oxides in the calculation was the arithmetic mean value between the molecular average molecular weight M.sub.w of the polyalkylene oxide used in the oxidation and the molecular average molecular weight M.sub.w of the polyalkylene oxide used as diol component. This approach is based on the simplified assumption that both structural units have been equally distributed in the polyalkylene oxide ester polymers.

[0318] This modified estimation is specifically explained for example 14, in which polyethylene oxide with M.sub.w=600 g/mol was nearly fully oxidized and polyethylene oxide with M.sub.w=1500 g/mol used as diol component. The mathematical equation for the estimation of the ester groups is

[00006]$\frac{4100-18}{\left[\left(600+1500\right)?0.5\right]-4}-1=2.9.$

and for the estimation of the ether groups

[00007]$\left\{\frac{\left[\left(600+1500\right)?0.5\right]-18}{44}-1\right\}?\frac{4100-18}{\left[\left(600+1500\right)?0.5\right]-4}=88.$

[0319] All polyalkylene oxide ester polymers obtained in examples 11 to 21 show a biodegradability in the range of 73 to 89% after 28 days, measured as CO.sub.2 formation relative to the theoretical value, although the weight average molecular weight M.sub.w covers 4 050 to even 18 300 g/mol. In contrast to that the biodegradability of a conventional polyethylene oxide with M.sub.w=8720 g/mol, measured by its CO.sub.2 formation within 28 days, is only very poor with a value of 16% although its M.sub.w value is well below 10 000 g/mol.

Examples 23 to 29

[0320] In examples 23 to 29, the property of the polyalkylene oxide ester polymers obtained by examples 16 to 21 as a carrier for scents was investigated and compared with a conventional PEG 9000 sample. 9 g of the respective polymer (details see table 3) were molten at 60? C. and mixed with 1 g of a mint fragrance mixture (boiling point: 207-228? C.). The molten mixture was dropped onto a cold plate to obtain pellets with a weight of around 40 mg. The theoretical content of the mint fragrance directly after the preparation of the pellets was 10 wt.-% and was also analytically determined by gas chromatography. The pellets were then stored for 12 weeks all together at 40? C. in a drying cabinet and the content of the mint fragrance again analytically determined by gas chromatography. The results are shown in table 3.

[0321] The experiments show that the amount of the mint fragrance in the pellets prepared with the polyalkylene oxide ester polymers is still in the range of 2.3 to 3.0 wt.-%, whereas it is only 2.2 wt.-% for the conventional PEG 9000 polymer. The higher scent retention of the polyalkylene oxide ester polymers enables either the use of a smaller amount of fragrance for a defined life time or a longer life time of the fragrance pellets.

[0322] In addition to that, the used polyalkylene oxide ester polymers are significantly better biodegradable than the conventional PEG 9000 polymer, leading to a biodegradation degree of high 73 to 79% for the polyalkylene oxide ester polymers and very low 16% for the conventional PEG 9000 polymer.

TABLE-US-00009 TABLE 1 Examples 1 to 10 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Type .sup.#1 and molecular EO EO EO EO EO EO EO EO EO EO average molecular 200 400 600 600 1000 1000 1500 1500 2000 2000 weight M.sub.w [g/mol] of polyalkylene oxide Number average of 3-4 8 12 12 21 21 33 33 44 44 number of ether groups Amount of polyalkylene 1500 1500 1500 1500 1500 1500 1500 1500 1500 1500 oxide [g] Amount of water [g] 3500 3500 3500 3500 3500 3500 3500 3500 3500 3500 Oxidation time [h] 6 6.5 35 8.5 45 10 62 11 85 12.5 Ratio in diacid 30 25 94 26 97 25 96 24 98 24 product [%] mono acid 37 50 5.8 50 3.1 50 3.9 50 2.0 50 diol .sup.#2 28 25 0.1 24 0.0 25 0.0 26 0.0 27 Ratio of oxidized OH 48.8 49.7 97.0 51.5 98.4 49.8 98.0 49.4 99.0 48.5 groups [%] .sup.#2 Physical property liquid liquid liquid liquid solid paste solid solid solid solid Hydroxy number 231.0 117.1 <2 79.1 <2 48.0 2.3 32 <2 22.7 [mg KOH/g] Acid number 268.3 136.8 173.8 91.7 106.2 54.4 70.2 37.1 51.8 26.0 [mg KOH/g] .sup.#1 EO = polyethylene oxide/EOPOEO = polypropylene oxide with CH.sub.2CH.sub.2OH end groups .sup.#2 Calculated on basis of the percentages of mono- and diacids

TABLE-US-00010 TABLE 2a Examples 11 to 20 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Classification .sup.#1 inv. inv. inv. inv. inv. inv. inv. inv. inv. inv. Educt mixture Ex. 1 Ex. 2 Ex. 3 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Esterification catalyst .sup.#2, 3 0.2 wt.-% 0.3 wt-% 0.15 wt-% 0.2 wt-% 0.1 wt.-% 0.25 wt-% 0.3 wt-% 0.2 wt.-% 0.15 wt.-% 0.2 wt-% cat 1 cat 2 cat 3 cat 3 cat 1 cat 2 cat 2 cat 1 cat 1 cat 3 Further diol .sup.#4 550 g 370 g 234 g 565 g 290 g PEG 600 PEG 1500 PEG 400 PEG 1500 PEG 1000 Reaction time [h] 5.5 6 8.5 10 8.0 5.0 5.5 8 5 7 K-value 9.9 13.6 23.3 26.6 26.7 28.6 30.5 32 29 33.5 Physical property liquid liquid liquid paste liquid paste solid solid solid solid M.sub.n [g/mol] 1580 2400 3600 4100 4350 3700 4230 5150 4940 6400 M.sub.w [g/mol] 4050 5450 10600 13600 14820 14470 13700 16850 16100 18300 PD (=M.sub.w/M.sub.n) 2.56 2.27 2.94 3.32 3.41 3.91 3.24 3.27 3.26 2.86 Average number of ether 25 46 73 88 89 77 90 112 108 139 groups in polymer .sup.#5 Average number of ester 7.0 5.0 5.0 2.9 6.3 4.3 3.2 2.4 2.3 3.3 groups in polymer .sup.#5 Biodegradation after 28 89 86.5 80.6 82.6 83.5 79 75 73 76 74 days according to OECD 301B [%] .sup.#6 .sup.#1 inv. = inventive/comp. = comparative .sup.#2 cat 1 = Ti(IV)-tetraisobutylat/cat 2 = methanesulfonic acid/cat 3 = Zn-octanoate .sup.#3 wt.-% relates to the educt mixture plus water. .sup.#4 PEG = polyethylene glycol = polyethylene oxide with two primary OH end groups .sup.#5 Calculated as described in the description of examples 11 to 22. .sup.#6 The percent values relate to the CO2 formation relative to the theoretical value.

TABLE-US-00011 TABLE 2b Examples 21 to 22 Ex. 21 Ex. 22 Classification .sup.#1 inv. comp. Educt mixture .sup.#4 Ex. 10 PEG 9000 Esterification catalyst .sup.#2, 3 0.2 wt.-% cat 1 Further diol .sup.#4 Reaction time [h] 4.5 K-value 30.4 25.4 Physical property solid solid M.sub.n [g/mol] 5400 6830 M.sub.w [g/mol] 16 630 8720 PD (=M.sub.w/M.sub.n) 3.08 1.28 Average number of ether 119 203 groups in polymer .sup.#5 Average number of ester 1.7 groups in polymer .sup.#5 Biodegradation after 28 days 79 16 according to OECD 301B [%] .sup.#6 .sup.#1 inv. = inventive/comp. = comparative .sup.#2 cat 1 = Ti(IV)-tetraisobutylat/cat 2 = methanesulfonic acid/cat 3 = Zn-octanoate .sup.#3 wt.-% relates to the educt mixture plus water. .sup.#4 PEG = polyethylene glycol = polyethylene oxide with two primary OH end groups .sup.#5 Calculated as described in the description of examples 11 to 22. .sup.#6 The percent values relate to the CO.sub.2 formation relative to the theoretical value.

TABLE-US-00012 TABLE 3 Examples 23 to 29 Ex. 23 Ex. 24 Ex. 25 Ex. 26 Ex. 27 Ex. 28 Ex. 29 Classification .sup.#1 inv. inv. inv inv. inv. inv. comp. Carrier polymer .sup.#2 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 PEG 9000 Mn [g/mol] 3700 4230 5150 4940 6400 5400 6830 Theoretical content of 10 10 10 10 10 10 10 mint fragrance before storage [wt.-%] Measured content of 9.3 9.4 9.4 9.2 9.3 9.5 9.2 mint fragrance before storage [wt.-%] Measured content of 2.3 2.6 2.6 2.9 2.7 3.0 2.2 mint fragrance after storage [wt.-%] Biodegradation of the 79 75 73 76 74 79 16 carrier polymer after 28 days according to OECD 301B [%] .sup.#1 inv. = inventive/comp. = comparative .sup.#2 PEG = polyethylene glycol = polyethylene oxide with two primary OH end groups