AMPHIPHILIC MULTIBLOCK POLYMERS

• US 20170096516A1
• Filed: 03/16/2015
• Published: 04/06/2017
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: Specialty Operations France
• Original Assignee: Rhodia Operations (Solvac SA)
• Inventors: HARRISSON, Simon, WILSON, James
• Granted Patent: US 10,450,397 B2
• Time in Patent Office: Days
• CPC Class Codes: C08F 2/22 Emulsion polymerisation
• CPC Class Codes: C08F 2/26 anionic
• CPC Class Codes: C08F 2/38 Polymerisation using regulators, e.g. chain terminating agents , e.g. telomerisation
• CPC Class Codes: C08F 220/1802 C2-(meth)acrylate, e.g. ethyl (meth)acrylate
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 220/1806 C6-(meth)acrylate, e.g. (cyclo)hexyl (meth)acrylate or phenyl (meth)acrylate
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 293/00 Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule on to polymers modified by introduction of unsaturated end groups C08F290/02
• CPC Class Codes: C08F 293/005 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent

Abstract

The present invention relates to a process for preparing a polymer with a mass Mw of less than 300 000 g/mol (especially between 1000 and 300 000 g/mol), comprising a step (E) of controlled radical polymerization in which the following are placed in contact in an aqueous medium in which are dispersed surfactant micelles:

• • ethylenically unsaturated hydrophilic monomers predominantly present in the aqueous medium;
  • partially water-soluble ethylenically unsaturated hydrophobic monomers different from the preceding monomers, at least partly present in the surfactant micelles, and having a solubility in the aqueous medium at least equal to that of hexyl acrylate;
  • at least one radical polymerization initiator; and
  • at least one radical polymerization control agent.

Claims

1. A process for preparing a polymer, the process comprising a polymerization step (E) in which the following are placed in contact in an aqueous medium (M) containing dispersed surfactant micelles:

ethylenically unsaturated monomers M1 predominantly present in the aqueous medium, referred to as “

hydrophilic monomers”

;

ethylenically unsaturated monomers M2 different from the hydrophilic monomers, at least partly present in the surfactant micelles, and having a solubility in the aqueous medium (M) at the implementation temperature of step (E) at least equal to that of hexyl acrylate, referred to as “

partially water-soluble hydrophobic monomers”

;

at least one radical polymerization initiator; and

at least one radical polymerization control agent.

2. The process as claimed in claim 1, wherein the radical polymerization control agent is a compound which comprises at least one thiocarbonylthio group —

S(C═

S)—

.

3. The process as claimed in claim 1, wherein the radical polymerization control agent is a prepolymer bearing at least one thiocarbonylthio group —

S(C═

S) obtained on conclusion of a step (E⁰), prior to step (E), said step (E⁰) placing in contact

monomers M0 bearing hydrophilic groups;

a radical polymerization initiator; and

a control agent bearing at least one thiocarbonylthio group —

S(C═

S)—

.

4. The process as claimed in claim 1, wherein the radical polymerization control agent is a water-soluble or water-dispersible oligomer bearing a thiocarbonylthio group —

S(C═

S)—

, which

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.

5. The process as claimed in claim 3, wherein the monomers (M0) are (meth)acrylic acid monomers, whereby the control agent is a poly(meth)acrylic acid bearing at least one xanthate group and the polymer having the specific structure obtained according to step (E) also with a poly(meth)acrylic acid block linked at one of its ends.

6. The process as claimed in claim 1, wherein the hydrophilic monomers of step (E) are (meth)acrylic acid monomers or acrylamido or methacrylamido monomers.

7. The process as claimed in claim 1, wherein the hydrophilic monomers of step (E) are 2-acryloylamino-2-methylpropane-1-sulfonic acids (AMPS) or acrylamide or acrylic acid.

8. The process as claimed in claim 1, wherein the partially water-soluble hydrophobic monomers of step (E) comprise acrylate monomers.

9. The process as claimed in claim 1, further comprising, after step (E), a step (E2) of grafting an ethylenically unsaturated group.

10. A polymer with a mass of less than 300 000 g/mol obtained according to the process of claim 1.

11. The polymer as claimed in claim 10, wherein the process further comprises, after step (E), a step (E2) of grafting an ethylenically unsaturated group.

12. A method

for modifying a liquid/liquid, liquid/solid or liquid/gas interface;

for regulating the rheology of a liquid medium; and

/or

for dispersing organic or mineral pigments

comprising using the polymer as claimed in claim 10.

13. A method for radical polymerization comprising using the polymer as claimed in claim 11 as an ethylenically unsaturated monomer.

14. The process according to claim 1, wherein the polymer has a weight-average molecular mass Mw of less than 300 000 g/mol.

15. The process according to claim 1, wherein the at least one radical polymerization initiator is water-soluble or water-dispersible.

16. The process according to claim 2, wherein the thiocarbonylthio group is a xanthate.

17. The process according to claim 3, wherein the monomers M0 bearing hydrophilic groups are identical to the hydrophilic monomers of step (E).

18. The process according to claim 3, wherein the at least one thiocarbonylthio group —

S(C═

S)—

of the control agent is a xanthate.

19. The process according to claim 8, wherein the acrylate monomers are selected from the group consisting of ethyl (meth)acrylate, ethyl ethacrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, tert-butyl ethacrylate and n-hexyl acrylate.

20. The polymer according to claim 10, wherein the mass is from 1000 to 300 000 g/mol.