Preparation of Polysiloxane Polyalkyleneglycol Brush Copolymers

Abstract

The present invention relates a hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer of the structure [A(-X—B)].sub.s, wherein: A represents said polysiloxane backbone; B represents said polyalkyleneglycol side chain; X is a linker group characterized by including the moiety Si—C—C— of which said Si is a part of the polysiloxane backbone A; and s is an integer of from 1 to 100, wherein the polysiloxane backbone A contains less than 500 ppm mol % of SiH moiety based on the total moles of the silicon atom which constitutes the polysiloxane backbone, and said copolymer has a polydispersity index of from 1.3 to 5.0; and a method for producing said hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer.

Claims

1. A hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer of the structure [A(-X—B)].sub.s, wherein: A represents said polysiloxane backbone; B represents said polyalkyleneglycol side chain; X is a linker group characterized by including the moiety Si—C—C— of which said Si is a part of the polysiloxane backbone A; and s is an integer of from 1 to 100, wherein the polysiloxane backbone A contains less than 500 ppm mol % of SiH moiety based on the total moles of the silicon atom which constitutes the polysiloxane backbone, and said copolymer has a polydispersity index of from 1.3 to 5.0.

2. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 1, wherein the polysiloxane backbone A contains less than 10 ppm mol % of SiH moiety based on the total moles of the silicon atom which constitutes the polysiloxane backbone.

3. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 1, wherein the copolymer has a number average molecular weight (Mn) of from 1000 to 200,000 g/mol.

4. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 1, wherein the copolymer is represented by Formula (I) ##STR00010## wherein: Z is a covalent bond or selected from a polyoxyalkylene having a molecular weight of less than 10000 g/mol or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom; R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may be the same or different and are independently selected from a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain one or more heteroatoms, wherein each R.sup.3, R.sup.4 and R.sup.5 may be independently selected within each unit n1, n2, n3, and p; R.sup.12 is selected from a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain one or more heteroatoms; R.sup.7 is selected from hydrogen or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain one or more heteroatoms 1; R.sup.8, R.sup.9, R.sup.10 and R.sup.11 may be the same or different and within each unit m they are independently selected from hydrogen or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain one or more heteroatoms; n1 and n2 is an integer independently selected from 0 to 1000, with the proviso that not both of n1 and n2 are 0; n3 is an integer from 0 to 10; p is an integer from 0 to 1000; and m is an integer from 1 to 1500.

5. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I): Z is selected from a C.sub.1-C.sub.20 alkylene group, a C.sub.6-C.sub.18 arylene group or a C.sub.6-C.sub.18 aralkylene group, which may contain at least one heteroatom; and/or R.sup.7 is selected from a C.sub.1-C.sub.12 alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.6-C.sub.18 aryl group or a C.sub.6-C.sub.18 aralkyl group, which may contain at least one heteroatom; and/or R.sup.12 is CR.sup.a.sub.2 where each R.sup.a may be the same or different and is independently selected from hydrogen, a C.sub.1-C.sub.12 alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.6-C.sub.18 aryl group or a C.sub.6-C.sub.18 aralkyl group, which may contain at least one heteroatom.

6. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I): Z is a C.sub.1-C.sub.20 alkylene group which may contain at least one heteroatom; and/or R.sup.7 is a C.sub.1-C.sub.8 alkyl group; and/or R.sup.12 is CR.sup.a.sub.2 where each R.sup.a is hydrogen.

7. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I) each of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a C.sub.1-C.sub.12 alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.6-C.sub.18 aryl group or a C.sub.6-C.sub.18 aralkyl group, which may contain at least one heteroatom.

8. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I) each of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a C.sub.1-C.sub.8 alkyl group.

9. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I) each of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from a methyl group or phenyl group.

10. The hydroxyl-functionalized unimodal polysiloxane polyalkyleneglycol brush copolymer according to claim 4, wherein in Formula (I) R.sup.8, R.sup.9 and R.sup.11 are hydrogen; and R.sup.10 is either a phenyl group or a C.sub.1-C.sub.8 alkyl group.

11. A method for producing the hydroxyl-functionalized polysiloxane polyalkyleneglycol brush copolymer according to claim 1, comprising the steps of a) reacting a hydroxyalkyl allyl ether having a primary or secondary alcohol group with a polyhydridosiloxane under anhydrous conditions and under catalysis of a transition metal catalyst of which the transition metal is selected from Groups 8 to 10 of the Periodic Table to provide a hydroxyl-functionalized polysiloxane prepolymer having Formula (II), ##STR00011## wherein: Z is a covalent bond or selected from a polyoxyalkylene having a molecular weight of less than 10000 g/mol or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may be the same or different and are independently selected from a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom, R.sup.12 is selected from a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom, R.sup.7 is selected from hydrogen or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom, n1 and n2 is an integer independently selected from 0 to 1000, with the proviso that not both of n1 and n2 are 0, n3 is an integer from 0 to 10, and p is an integer from 0 to 1000, said hydroxyalkyl allyl ether conforming to Formula (IV), and ##STR00012## wherein Z, R.sup.12 and R.sup.7 are as defined above, said polyhydridosiloxane conforms to Formula (V) ##STR00013## wherein: R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and p are as defined above; and n is n1+n2+n3, and b) in the presence of the obtained hydroxyl-functionalized polysiloxane prepolymer of Formula (II) and a catalyst, performing a ring-opening polymerization of at least one alkylene oxide monomer having Formula (III): ##STR00014## wherein: each R.sup.8, R.sup.9, R.sup.10 and R.sup.11 may be the same or different and are independently selected from hydrogen or a linear, branched or cyclic hydrocarbon residue having 1 to 20 carbon atoms which may contain at least one heteroatom.

12. The method according to claim 11, wherein the catalyst is an alkoxylation catalyst.

13. The method according to claim 11, wherein the alkoxylation catalyst is selected from the group consisting of alkali metal hydroxides, alkali earth metal hydroxides, alkali metal alkoxides, alkali earth metal alkoxides, and double metal cyanide complex.

14. The method according to claim 11, wherein the alkoxylation catalyst is a double metal cyanide complex.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0113] FIG. 1 shows the GPC curve of Example 3.

[0114] FIG. 2 shows the GPC curve of Example 4.

[0115] FIG. 3 shows the GPC curve of Example 5.

[0116] FIG. 4 shows the GPC curve of Example 6.

[0117] FIG. 5 shows the GPC curve of Comparative Example 7.

[0118] FIG. 6 shows the GPC curve of Comparative Example 8.

EXAMPLES

Example 1

Preparation of 1-(allyloxy)propan-2-ol

[0119] ##STR00006##

[0120] In a 1 L autoclave equipped with dosage system, 637.5 g (10.98 mol) of allyl alcohol were placed. Under argon flow, Na (2.9% mol) was added into the vessel. The mixture was stirred at room temperature until the gas evolution ceased. Then the autoclave was closed and heated until 110° C. In the next step propylene oxide (PO) was dosed (520 ml, dosage rate 1.25 g/min). After the completion of the addition of PO it was allowed to cool to room temperature and the reaction mixture was stirred overnight. A yellow transparent mixture was obtained. The mixture was neutralized using HCl (solution 37% in water) and dried with Na.sub.2SO.sub.4. The mixture was filtrated trough celite and distilled under vacuum (100 mbar, 85-95° C.). The product was obtained with good yield (70-75%) and the structure was confirmed by NMR spectroscopy and mass spectrometry.

Example 2

Preparation of (3-(2-hydroxypropoxy)propyl)methylsiloxane-co-polydimethylsiloxane

[0121] ##STR00007##

[0122] A 250 ml three neck round bottomed flask was degassed under high vacuum (1.sup.−3 mbar) and flushed with argon. Then, 110 μL of Karstedt (2% of Pt in the catalyst, 0.1% mol in the mixture) and toluene (50 ml, dried over molecular sieves) were added into the flask under argon atmosphere and stirred at room temperature (20° C.) for a couple of minutes. Then 1-(allyloxy)propan-2-ol (the product from example 1; 3.8 ml) was added into the system. Polyhydridomethylsiloxane-co-polydimethylsiloxane (12.5 g, Mn 2900 g/mol) were added dropwise. The mixture was stirred and refluxed (oil bath temperature: 120° C.) under inert atmosphere (Ar) until complete conversion of the SiH groups was achieved (the reaction was followed by .sup.1H-NMR). The mixture (when necessary) was decolorized by adding activated carbon and an excess of pentane and stirred for 16 h at room temperature. The crude was filtrated trough celite, and the solvents and volatiles were evaporated under vacuum. The obtained product (yield 85-95%) was a colorless, transparent viscous liquid. The molecular weight and structure of the product was confirmed by GPC and NMR spectroscopy. No traces of Pt were detectable in the mixture (by ICP).

Example 3

Preparation of Polydimethylsiloxane-Graft-Poly(Propylene Oxide)

[0123] ##STR00008##

[0124] 5.0 g of (3-(2-hydroxypropoxy)propyl)m ethylsiloxane-co-polydimethylsiloxane (from example 3 Mn: 3596 g/mol) were charged together with 0.015 g of the DMC catalyst (500 ppm based on the amount of the copolymer) and 20.0 g heptane in a 100 mL—stirring Autoclave. The reaction mixture was stirred at room temperature with constant stirring at 350 rpm for several minutes under vacuum (0.001 bar) and argon atmosphere (1 bar). Then the reaction temperature was increased at 110° C. After reaching this temperature, 3.5 mL propylene oxide (PO) were added to the reaction mixture and stirred constantly at 350 rpm. After filtration (when necessary) the solvent and traces of unreacted monomer were removed under vacuum (0.001 bar) for three hours. The yield of the product was found to be 90%. The product is milky, colorless, viscos liquid.

Example 4

Preparation of Polydimethylsiloxane-Graft-Poly(Propylene Oxide)

[0125] The procedure is the same as shown in Example 3. The volume of added PO is 7.0 mL.

Example 5

Preparation of Polydimethylsiloxane-Graft-Poly(Propylene Oxide)

[0126] The procedure is the same as shown in Example 3. The volume of added PO is 10.5 mL.

Example 6

Preparation of Polydimethylsiloxane-Graft-Poly(Propylene Oxide)

[0127] The procedure is the same as shown in Example 3. The volume of added PO is 14.0 mL.

Comparative Example 7 (Adapted from High Performance Polymers (2005), 17(2), 303-312)

[0128] This comparative example is used to describe the advantage of the presented invention compared to the known grafting onto copolymerization. The desired product should give the identical product as it is shown in Example 4.

##STR00009##

[0129] A 50 ml three neck round bottomed flask fitted with a cooling condenser was degassed under high vacuum (1.sup.−3 mbar) and flushed with argon. Polyhydridomethylsiloxane-co-polydimethylsiloxane (5.0 g, Mn 2900 g/mol) and 5 mL dried Toluene were introduced into it and heated up to 90° C. 0.05 mL solution 2% H.sub.2PtCl.sub.6 in anhydrous isopropanol was added. 8.4 g propoxylated 1-(allyloxy)propan-2-ol (Mn 813 g/mol) and and 5 mL dried Toluene were added to the mixture. The reaction was stirred at 130° C. after completion of addition for 24 hours. Then, the toluene was removed by heating the reaction mixture under vacuum and the crude copolymer was obtained.

[0130] The crude product was diluted in pentane and methanol and then dried under vacuum again. The obtained product (yield 90%) was a slightly milky, brown, viscous liquid. The molecular weight and structure of the product was confirmed by GPC and NMR spectroscopy.

Comparative Example 8 (Adapted from JP2011231073 A)

[0131] This comparative example is used to describe the advantage of the presented invention compared to the known grafting onto copolymerization. The desired product should give the identical product as it is shown in Example 4.

[0132] A 50 ml three neck round bottomed flask fitted with a cooling condenser was degassed under high vacuum (1.sup.−3 mbar) and flushed with argon. Polyhydridomethylsiloxane-co-polydimethylsiloxane (5.0 g, Mn 2900 g/mol) and 5 mL dried Toluene were introduced into it and heated up to 70° C. 8.4 g propoxylated 1-(allyloxy)propan-2-ol (Mn 813 g/mol) and 0.04 g of Karstedt (2% of Pt in the catalyst) were added dropwise at 70° C. while stirring under argon. The reaction was continued at 100° C. after completion of addition. The mixture was stirred and refluxed (oil bath temperature: 100° C.) under inert atmosphere (Ar) for 24 hours. The crude was (if necessary) filtrated, and the solvents and volatiles were evaporated under vacuum. The obtained product (yield 65%) was a brown, transparent viscous liquid. The molecular weight and structure of the product was confirmed by GPC and NMR spectroscopy.

Methods:

NMR-Spectroscopy:

[0133] All NMR measurements were done on a Bruker 600 MHz instrument. The NMR measurements are quantitative .sup.1H-NMR (D1=30 s) with deuterated chloroform as solvent and naphthalene (0.00770848 mmol) as external standard. All the samples were measured at room temperature (297 K). The chemical shifts are given in ppm. The calibration of the chemical shifts in 1H spectra was carried out by using the shifts of the deuterated solvents (CDCl3; δH 7.26).

GPC:

[0134] Gel permeation chromatography was carried out using HP1090 II Chromatography with DAD detector (HEWLETT PACKARD) at 40° C. Tetrahydrofuran (THF) was used as an eluent. THF was passed through three PSS SDV gel columns with molecular weight ranges of 102, 103 and 104 g.Math.mol−1 with a flow rate of 0.9 ml.Math.min−1. The calibration of the device was carried out using polystyrene standards.

Table 1 shows the reaction conditions of Examples 3 to 6.

TABLE-US-00001 TABLE 1 Examples 3 to 6 with different amounts of propylene oxide (PO) DMC Degree of Molecular Starter Solvent catalyst PO polymerization weight Polydispersity Ex. 3 5 g 20 g 15 mg  3.5 mL  6  5684 g/mol 2.02 Ex. 4 5 g 20 g 15 mg  7.0 mL 12  7424 g/mol 2.32 Ex. 5 5 g 20 g 15 mg 10.5 mL 18 10208 g/mol 2.89 Ex. 6 5 g 20 g 15 mg 14.0 mL 23 11948 g/mol 1.85
The molecular weight was calculated by .sup.1H-NMR and the polydispersity was measured by GPC.

[0135] Table 2 shows that a full conversion was not achieved in Comparative Examples 7 and 8, whereas a substantially full conversion was achieved in Example 4. The percentages were calculated by the integration of .sup.1H-NMR spectroscopy and the external standard naphthalene.

TABLE-US-00002 TABLE 2 Content of unreacted Degree of Molecular SiH moiety polymerization weight Polydispersity Ex. 4  17 ppm 12 7347  2.02 mol % g/mol Comparative 655 ppm 12 2571  3.29 Ex. 7 mol % g/mol Comparative 621 ppm 12 4665 22.63 Ex. 8 mol % g/mol