ONE POT PROCESS FOR THE PREPARATION OF POLY (1, 3-ALKENES)-BLOCK-POLY (ALKYLENE OXIDES) COPOLYMERS

Abstract

The present invention relates to an improved process for the preparation of poly (1,3-alkenes)-block-poly (alkylene oxides) copolymers. Furthermore, this invention also relates to the purification of crude amphiphilic block copolymers PD-b-PAO having oligomers and low molecular weight polymers.

Claims

1. A process for the one pot preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer of Formula (I) ##STR00011## comprising the steps of— a) reacting 1,3-alkenes of Formula (II) with Initiator-1 of Formula I-Li in presence of a solvent to provide Lithium Poly(1,3-alkenes)(III), followed by end capping with alkylene oxide to provide a Lithium alkoxy poly(1,3-alkene) of Formula (IV); and ##STR00012## b) replacing of Lithium counter ion of Lithium alkoxy poly (1,3-alkene) of formula (IV) with Initiator-2 comprising potassium tertiary butoxide and 18-Crown ethers for alkyleneoxide polymerization, followed by reaction with alkylene oxide to yield Poly (1,3-alkenes)-block-poly(alkylene oxide) copolymer. ##STR00013##

2. A process for the preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer according to claim 1, wherein 1,3-alkenes monomers are selected from 1,3-Butadiene, 1-Methoxy-1,3-Butadiene, trans-1,3-Pentadiene, 1-Acetoxy-1,3-butadiene and Isoprene.

3. A process for the preparation of Poly(1,3-alkenes)-block-poly-(alkylene oxide) copolymer according to claim 1, wherein Initiator-1 is selected from n-Butyl Lithium and sec-butyllithium.

4. A process for the preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer according to claim 1, wherein solvent is selected from Tetrahydrofuran and end capping had been performed using alkylene oxide selected from Ethylene oxide.

5. A process for the preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer according to claim 1, wherein alkylene oxide monomers are selected from 1,2-Epoxybutane, cis-2,3-Epoxybutane, 1,2-Epoxyhexane, 3,4-Epoxy-1-butene, 1,2-Epoxy-3-phenoxypropane, (2,3-Epoxypropyl)benzene, (±)-Propylene oxide, Styrene oxide, α-Pinene oxide, Allyl glycidyl ether, Glycidyl 2,2,3,3-tetrafluoropropyl ether, Cyclohexene oxide and Furfuryl glycidyl ether.

6. A process for the purification crude amphiphilic block copolymers PD-b-PAO having oligomers and low molecular weight polymers and inorganic salts, comprising: a) dissolution of the crude polymer in Ethyl acetate and washing with the pure water to eliminate the oligomers, 18C6 and inorganic content; b) extracting using Soxhlet extraction process by Embedding the polymer on silica gel and then refluxing with acetone for 10 h; and c) filtration of the polymer, followed by removal of solvent to yield highly pure copolymers PD-b-PAO.

7. A process for the purification crude amphiphilic block copolymers PD-b-PAO according to claim 6, acetone is selected for soxhlet extraction.

8. One pot process for the preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer of Formula (I) ##STR00014## comprising the steps of— a) reacting 1,3-alkenes of Formula (II) with Initiator-1 of Formula I-Li in presence of a solvent to provide Lithium Poly(1,3-alkenes)(III), followed by end capping with alkylene oxide to provide a Lithium alkoxy poly(1,3-alkene) of Formula (IV); and ##STR00015## b) replacing of Lithium counter ion of Lithium alkoxy poly (1,3-alkene) of formula (IV) with Initiator-2 comprising potassium tertiary butoxide and 18-Crown ethers for alkylene oxide polymerization, followed by reaction with alkylene oxide to yield Poly (1,3-alkenes)-block-poly(alkylene oxide) copolymer. ##STR00016##

9. One pot process for the preparation of Poly(1,3-alkenes)-block-poly(alkylene oxide) copolymer according to claim 6, wherein 1,3-alkenes monomers are selected from 1,3-Butadiene, 1-Methoxy-1,3-Butadiene, trans-1,3-Pentadiene, 1-Acetoxy-1,3-butadiene and Isoprene and Initiator-1 is selected from n-Butyl Lithium and secondary butyl lithium.

10. One pot process for the preparation of Poly (1,3-alkenes) block-Poly (alkylene oxide) copolymer according to claim 6, wherein solvent is selected from Tetrahydrofuran end capping had been performed using alkylene oxide selected from Ethylene oxide; alkylene oxide monomers selected from Ethylene oxide, 1,2-Epoxybutane, cis-2,3-Epoxybutane, 1,2-Epoxyhexane, 3,4-Epoxy-1-butene, 1,2-Epoxy-3-phenoxypropane, (2,3-Epoxypropyl)benzene, (±)-Propylene oxide, Styrene oxide, α-Pinene oxide, Allyl glycidyl ether, Glycidyl 2,2,3,3-tetrafluoropropyl ether, Cyclohexene oxide and Furfuryl glycidyl ether.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention relates to a process for the preparation of Poly (1,3-alkenes)-block-poly (alkylene oxide) copolymer of Formula (I) comprising the steps of reacting 1,3-alkenes with metal initiator in the presence of solvent selected from tetrahydrofuran to provide metal alkoxy poly (1,3-alkene) of formula III, followed by end capping with ethylene oxide to provide a metal alkoxy poly (1,3-alkene) of formula (IV); wherein replace of metal counter ion of metal alkoxy poly (1,3-alkene) of formula (IV) with Initiator-2 comprising of potassium tertiary butoxide and 18-Crown ethers for alkylene oxide polymerization, followed by reaction with alkylene oxide to yield Poly (1,3-alkenes)-block-poly (alkylene oxide) copolymer; wherein the metal initiator is selected from the group consisting of n-Butyl Lithium and sec-butyllithium more preferably sec-butyllithium; the solvent is selected from tetrahydrofuran, hexane and water; the alkylene oxide is selected from 1,2-Epoxybutane, cis-2,3-Epoxybutane, 1,2-Epoxyhexane, 3,4-Epoxy-1-butene, 1,2-Epoxy-3-phenoxypropane, (2,3-Epoxypropyl)benzene, (±)-Propylene oxide, Styrene oxide, α-Pinene oxide, Allyl glycidyl ether, Glycidyl 2,2,3,3-tetrafluoropropyl ether, Cyclohexene oxide and Furfuryl glycidyl ether; wherein 1,3-alkenes monomers are selected from 1,3-Butadiene, 1-Methoxy-1,3-Butadiene, trans-1,3-Pentadiene, 1-Acetoxy-1,3-butadiene and Isoprene; wherein solvent is selected from Tetrahydrofuran, and end capping had been performed using alkylene oxide selected from Ethylene oxide.

[0029] Another embodiment of the present invention relates to one pot process for the preparation of Poly (1,3-alkenes)-block-poly (alkylene oxide) copolymer of Formula (I)

##STR00008##

comprising the steps of— [0030] a) reacting 1,3-alkenes of Formula (II) with Initiator-1 of Formula I-Li in presence of a solvent to provide Lithium Poly (1,3-alkenes)(III), followed by end capping with alkylene oxide to provide a Lithium alkoxy poly(1,3-alkene) of Formula (IV); and

##STR00009## [0031] b) replacing of Lithium counter ion of Lithium alkoxy poly (1,3-alkene) of formula (IV) with Initiator-2 comprising of potassium tertiary butoxide and 18-Crown ethers for alkylene oxide polymerization, followed by reaction with alkylene oxide to yield Poly (1,3-alkenes) block-Poly (alkylene oxide) copolymer.

##STR00010##

[0032] Wherein the metal initiator is selected from the group consisting of n-Butyl Lithium and sec-butyllithium more preferably sec-butyllithium; the solvent is selected from tetrahydrofuran, hexane and water; the alkylene oxide is selected from 1,2-Epoxybutane, cis-2,3-Epoxybutane, 1,2-Epoxyhexane, 3,4-Epoxy-1-butene, 1,2-Epoxy-3-phenoxypropane, (2,3-Epoxypropyl)benzene, (±)-Propylene oxide, Styrene oxide, α-Pinene oxide, Allyl glycidyl ether, Glycidyl 2,2,3,3-tetrafluoropropyl ether, Cyclohexene oxide and Furfuryl glycidyl ether; wherein 1,3-alkenes monomers are selected from 1,3-Butadiene, 1-Methoxy-1,3-Butadiene, trans-1,3-Pentadiene, 1-Acetoxy-1,3-butadiene and Isoprene; wherein solvent is selected from Tetrahydrofuran, and end capping had been performed using alkylene oxide selected from Ethylene oxide.

[0033] Another embodiment of the present invention relates to a process for the purification crude amphiphilic block copolymers PD-b-PAO having oligomers and low molecular weight polymers and inorganic salts, comprising: [0034] a. dissolution of the crude polymer in Ethyl acetate and washing with the pure water to eliminate the oligomers, 18C6 and inorganic content; [0035] b. extracting using Soxhlet extraction process by Embedding the polymer on silica gel and then refluxing with acetone for 10 h; and [0036] c. filtration of the polymer, followed by removal of solvent to yield highly pure copolymers PD-b-PAO.

EXAMPLES

Example 1: Purification of Monomers (Distillation of 1,3-diene Monomer)

[0037] 1 3-diene and n-butyl lithium in hexane were charged in to 500 ml two neck round bottom flask and stirred for one hour to remove the moisture. The monomer is freezing by adding the liquid nitrogen and melting under argon atmosphere for removal of dissolved oxygen. Distillation has been started slowly at −45° C. under static vacuum, after completion of distillation the material was stored in deep freezer and maintained at −30° C.

Example 2: Distillation of Alkylene Oxide Monomer

[0038] Alkylene oxide monomer and calcium hydride were taken into a round bottom flask and stirred for one hour to remove the moisture. The monomer is freezing by adding the liquid nitrogen and melting under argon atmosphere for removal of dissolved oxygen. Distillation has been started slowly at −45° C. under static vacuum, after completion of distillation the material was stored in deep freezer and maintained at −30° C.

Example 3: Distillation of Tetrahydrofuran (THF)

[0039] Distillation of THF has been performed in two stages and is described below

[0040] First Stage Distillation of THF

[0041] Tetrahydrofuran, sodium metal and benzophenone were taken in round bottom flask under argon atmosphere and reflux for 1 hour at 80° C., after completion of reflux collected the THF under argon and allowed to cool at room temperature. The collected THF in threaded air tight RB flask before starting the distillation.

[0042] Second Distillation of THF:

[0043] First stage collected tetrahydrofuran is taken in round bottom flask and n-butyl lithium in hexane solution was added to slowly in drop wise until the yellow colour is developed. Freezed the solvent mixture under liquid nitrogen and melted under argon atmosphere for the removal of the oxygen traces. Finally THF is distilled off in the solvent collector and has further used for polymerization reaction.

Example 4: Typical Procedure for the Preparation of Anionic Polymerization Procedure of poly (1,3-butadiene)-b-poly(ethylene oxide)

[0044] The polymerization set up is made by connecting the polymerization reactor made with ace threads with condenser manifold made by ace threaded joints. The total reaction set up is heated with hot air gun under high vacuum after few minutes the reaction setup is cooled under argon. 100 ml of distilled THF is added slowly added to the polymerization reaction, double distilled 1,3-butadiene is added through cannula THF containing reactor and maintained at −78° C., an initiator sec-butyllithium solution is added to the reaction mixture at same temperature. The reaction is continued for four hours at −60° C. Finally, ethylene oxide had been added to the reaction mixture for end capping and maintained for one hour. After completion of the reaction to get the capping extent of Lithiated poly (1,3-butadiene) is reacted with potassium tert-butoxide to obtain poly (1,3-butadine) with its potassium salt. Ethylene oxide product has been added to the above reaction mixture through cannula under cold condition at argon atmosphere. The reaction is maintained for 24 hours at 40° C. under argon atmosphere to get the reaction mass is quenched with 1N HCl in methanol to obtain a title product with high purity.

[0045] While the foregoing pages provide a detailed description of the preferred embodiments of the invention, it is to be understood that the summary, description and examples are illustrative only of the core of the invention and non-limiting. Furthermore, as many changes can be made to the invention without departing from the scope of the invention, it is intended that all material contained herein be interpreted as illustrative of the invention and not in a limiting sense.