Preparation of amphiphilic block polymers by controlled radical micellar polymerisation

Patent metadata

Field	Value
Publication number	US-9580535-B2
Application number	US-201214353360-A
Country	US
Kind code	B2
Filing date	Oct 24, 2012
Priority date	Oct 24, 2011
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

The present invention relates to the preparation of block copolymers, which can be used in particular as rheology agents, suitable, inter alia, for oil extraction, comprising a step of radical micellar polymerization wherein the following are brought into contact in an aqueous medium: —hydrophilic monomers, dissolved or dispersed in the aqueous medium; —hydrophobic monomers in the form of a micellar solution, i.e. containing, in a dispersed state, micelles comprising these hydrophobic monomers; —at least one radical polymerization initiator; and —at least one radical polymerization control agent. The polymers obtained according to the invention can be used in particular for enhanced oil recovery (EOR).

First claim

The invention claimed is:

1. A process for preparing a block copolymer, which comprises a step (E) of micellar radical polymerization in which the following are placed in contact, in an aqueous medium (M):
hydrophilic monomers, dissolved or dispersed in said aqueous medium (M);
hydrophobic monomers in the form of a micellar solution, i.e. containing, in dispersed form in the medium (M), micelles comprising these hydrophobic monomers;
at least one radical polymerization initiator, and
at least one radical polymerization control agent, in which the radical polymerization control agent is a compound comprising a thiocarbonylthio group —S(C═S)—.

2. The process as claimed in claim 1 , in which the thiocarbonylthio group —S(C═S)— has a formula —SC═S—O—.

3. The process as claimed in claim 1 , wherein the radical polymerization control agent compound comprising the thiocarbonylthio group —S(C═S)— is an oligomer of water-soluble or water-dispersible nature bearing the thiocarbonylthio group —S(C═S)—, and
is soluble or dispersible in the aqueous medium (M) used in step (E); and/or
is not capable of penetrating into the micelles of the micellar solution.

4. The process as claimed in claim 3 , wherein the radical polymerization control agent is a prepolymer bearing the thiocarbonylthio group —S(C═S)—, obtained after a step (E 0 ), prior to said step (E), said step (E 0 ) placing the following in contact:
hydrophilic monomers identical in formula to said hydrophilic monomers used in step E;
said radical polymerization initiator; and
a radical pre-polymerization control agent bearing the thiocarbonylthio group —S(C═S)—.

5. The process as claimed in claim 1 , wherein the hydrophilic monomers of said step (E) comprise (meth)acrylic acid and/or acrylamido or methacrylamido monomers.

6. The process as claimed in claim 5 , wherein the hydrophilic monomers of said step (E) are (meth)acrylamides.

7. The process as claimed in claim 1 , wherein the radical polymerization initiator used in said step (E) is a redox initiator.

8. The process as claimed in claim 7 , wherein the redox initiator comprises a combination of ammonium persulfate and sodium formaldehyde sulfoxylate.

9. The process as claimed in claim 1 , wherein the reaction medium of said step (E) is free of copper or comprises copper in combination with a copper-complexing agent, in an amount capable of masking its presence.

10. The process as claimed in claim 1 , wherein the process of the invention comprises, after said step (E), a step (E1) of hydrolysis, ozonolysis or reaction with amines, which is capable of deactivating and/or destroying all or some transfer groups present on the polymer prepared in said step (E) resulting from the radical polymerization control agent of step (E).

11. The process as claimed in claim 4 , wherein the prepolymer has a polymer chain of 2 to 15 said hydrophilic monomer units.

12. The process as claimed in claim 1 , wherein the radical pre-polymerization control agent of step E 0 has a formula (A):

wherein
Z represents:
a hydrogen atom,
a chlorine atom,
an optionally substituted alkyl or optionally substituted aryl radical,
an optionally substituted heterocycle,
an optionally substituted alkylthio radical,
an optionally substituted arylthio radical,
an optionally substituted alkoxy radical,
an optionally substituted aryloxy radical,
an optionally substituted amino radical,
an optionally substituted hydrazine radical,
an optionally substituted alkoxycarbonyl radical,
an optionally substituted aryloxycarbonyl radical,
an optionally substituted carboxyl or acyloxyl radical,
an optionally substituted aryloxy radical,
an optionally substituted carbamoyl radical, a cyano radical,
a dialkyl- or diaryl-phosphonato radical, a dialkyl-phosphinato or diaryl-phosphinato radical, or
a polymer chain, and

R 1 represents an optionally substituted alkyl, acyl, aryl, aralkyl, alkene or alkyne group containing 1 to 20 carbon atoms,
wherein the groups R 1 and Z, when they are substituted, are independently substituted with a member of the group consisting of
optionally substituted phenyl groups, optionally substituted aromatic groups, saturated or unsaturated carbocycles, saturated or unsaturated heterocycles, alkoxycarbonyl or aryloxycarbonyl of formula —COOR, carboxyl of formula —COOH, acyloxy of formula —O 2 OR, carbamoyl of formula —CONR 2 , cyano of formula —CN, alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxyl of formula —OH, amino of formula —NR 2 , halogen, perfluoroalkyl C n F 2n+1 , allyl, epoxy, alkoxy of formula —OR, S-alkyl, S-aryl, groups of hydrophilic or ionic nature selected from alkali metal salts of carboxylic acids, alkali metal salts of sulfonic acid, polyalkylene oxide chains of formula PEO and/or PPO, cationic substituents selected from quaternary ammonium salts, wherein R of the aryloxycarbonyl, acyloxy, carbamoyl, amino, and alkoxy representing an alkyl or an aryl group, or a polymer chain.

13. The process as claimed in claim 1 , in which the thiocarbonylthio group —S(C═S)— has a formula —S(C═S)OCH 2 CH 3 .

14. The process as claimed in claim 1 , in which the radical polymerization control agent compound has a formula R 1 —S(C═S)OCH 2 CH 3 , wherein R 1 represents an optionally substituted alkyl group, wherein when the group R 1 is substituted, it is substituted with a member of the group consisting of alkoxycarbonyl or aryloxycarbonyl of formula —COOR, carboxyl of formula —COOH.

15. The process as claimed in claim 1 , wherein the radical polymerization control agent compound comprising the thiocarbonylthio group —S(C═S)— has a formula (A):

wherein
Z represents an alkoxy radical,
R 1 represents an optionally substituted alkyl group, wherein when the group R 1 is substituted, it is substituted with a member of the group consisting of alkoxycarbonyl or aryloxycarbonyl of formula —COOR, carboxyl of formula —COOH.

16. A process for preparing a block copolymer, which comprises a step (E) of micellar radical polymerization in which the following are placed in contact, in an aqueous medium (M): —hydrophilic monomers, dissolved or dispersed in said aqueous medium (M); —hydrophobic monomers in the form of a micellar solution, i.e. containing, in dispersed form in the medium (M), micelles comprising these hydrophobic monomers; —at least one radical polymerization initiator, and —at least one radical polymerization control agent, wherein the radical polymerization control agent is a prepolymer bearing the thiocarbonylthio group —S(C═S)—, obtained after a step (E°), prior to said step (E), said step (E°) placing the following in contact: —hydrophilic monomers identical in formula to said hydrophilic monomers used instep E; —said radical polymerization initiator; and a radical pre-polymerization control agent hearing the thiocarbonylthio group —S(C═S)—, wherein the radical polymerization initiator used in said step (E) is a redox initiator comprising a combination of ammonium persulfate and sodium formaldehyde sulfoxylate.

Assignees

• Rhodia Operations

Inventors

• Wilson James
• Destarac Mathias
• Cadix Arnaud

Classifications

• C09K8/882

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C09K8/588

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title

• C08F293/005

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C09K8/04

  Aqueous well-drilling compositions · CPC title

• C08F2/38 Primary

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title