Process for Preparing Copolymers by Anionic Solvent-Free Polymerization

• US 20080312376A1
• Filed: 11/28/2006
• Published: 12/18/2008
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique, Universite De Montpellier II Sciences Et Techniques Du Languedoc
• Inventors: Guerrouani, Nadia, Mas, Andre, Schue, Francois
• Granted Patent: US 7,884,157 B2
• Time in Patent Office: Days
• US Class Current: 525/61
• CPC Class Codes: C08G 2261/126 block
• CPC Class Codes: C08G 2261/128 graft
• CPC Class Codes: C08G 63/664 derived from hydroxy carboxylic acids
• CPC Class Codes: C08G 63/823 for the preparation of polylactones or polylactides

Abstract

The invention concerns a process for preparing a block or comb copolymer comprising at least one hydrophilic portion and at least two hydrophobic portions, by anionic solvent-free polymerization of a prepolymer selected from a polyethylene glycol and a polyvinyl alcohol, and of a lactone or dilactone monomer. The process is carried out in the presence of an alkaline-earth metal hydride, in an inert atmosphere, and the polymerization step is not carried out under vacuum. The invention also concerns copolymers obtained by this process.

Claims

1-10. -10. (canceled)

11. A process for preparing a block or comb copolymer comprising at least one hydrophilic portion and at least two hydrophobic portions, said process comprising polymerizing a prepolymer selected from a polyethylene glycol and a polyvinyl alcohol, and a lactone or dilactone monomer by anionic solvent-free polymerization, wherein said anionic solvent-free polymerization is carried out in the presence of an alkaline-earth metal hydride and in an inert atmosphere, with the proviso that the polymerization step is not carried out under vacuum.

12. The process according to claim 11, wherein said alkaline-earth metal hydride is selected from calcium hydride CaH₂ and magnesium hydride MgH₂.

13. The process according to claim 11, wherein said lactone or dilactone monomer is selected from L-lactide, glycolide, β

-butyrolactone, δ

-valerolactone and ε

-caprolactone.

14. The process according to claim 11, wherein said inert atmosphere is an argon atmosphere or is a nitrogen atmosphere.

15. The process according to claim 11, wherein the prepolymer is a polyethylene glycol, and polymerization is carried out at a temperature of 115°

C. to 125°

C. for a period of 14 to 16 hours.

16. The process according to claim 11, wherein the prepolymer is polyvinyl alcohol, and polymerization is carried out at a temperature of 140°

C. to 150°

C. for a period of 36 to 54 hours.

17. A copolymer obtainable by the process according to claim 11, wherein said copolymer is stereoregular.

18. The copolymer according to claim 17, comprising a PEG block between two polylactone blocks.

19. The copolymer obtainable by the process according to claim 11, comprising recurrent —

CH₂—

CH(OH)—

units and recurrent —

CH₂—

CH(OR)—

units in which R represents a polylactone chain.

20. The copolymer according to claim 19, wherein the polylactone chain is derived from a monomer selected from L-lactide, glycolide, β

-butyrolactone, δ

-valerolactone and ε

-caprolactone.