Initiator for surface-based polymerization and use thereof

Patent metadata

Field	Value
Publication number	US-10400054-B2
Application number	US-201816001027-A
Country	US
Kind code	B2
Filing date	Jun 6, 2018
Priority date	Dec 11, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

Disclosed are polymerization initiators as may be utilized for addition of polymers to a substrate surface. The initiators are azo-based initiators that include multi-functionality through addition of multiple anchoring agents to an inner azo group. Disclosed polymerization initiators can be utilized to form high density and high molecular weight polymers on a surface such as a particulate surface. Formed materials can be beneficial in one embodiment in fracking applications, providing composite proppant/polymer materials that can prevent leakage of polymers from a subterranean geologic formation.

First claim

What is claimed:

1. A composite particle comprising a polymerization initiator bonded to a surface of a particle, the polymerization initiator comprising an azo-group comprising a first and second end, a first anchoring agent and a second anchoring agent, the first and second anchoring agents being bonded to the first and second ends, respectively, of the azo-group, at least one of the first and second anchoring agents being bonded to the surface of the particle.

2. The composite particle of claim 1 , the polymerization initiator having the general structure of:
X 1 —R 1 -A 1 -N═N-A 2 -R 2 —X 2

in which
A 1 and A 2 are the same as or different from one another and each comprise an attachment group,
R 1 and R 2 are the same as or different from one another and each comprise a linkage group,
X 1 and X 2 are the same as or different from one another and each comprise the first and second anchoring agents, respectively.

3. The composite particle of claim 2 , wherein A 1 and A 2 have the general structure:

in which
R 3 and R 4 independently comprise H, CN, CH 3 , COOR 6 (R 6 ═H or alkyl), or C 2 H 5 ; and
R 5 is an alkyl group.

4. The composite particle of claim 2 , wherein R 1 and R 2 independently comprise a carbonyl-containing linkage, an amine-containing linkage, a thiol-containing linkage, a phosphonate linkage, an epoxy linkage, an alkene-containing linkage, or are a bond.

5. The composite particle of claim 2 , wherein X 1 and X 2 each independently comprise a thiol group, a phosphonate group, or a halogen.

6. The composite particle of claim 1 , wherein at least one of the first and second anchoring agents are bonded to the surface via thiozoline reactivity.

7. The composite particle of claim 1 , wherein at least one of the first and second anchoring agents are bonded to the surface via succinimide reactivity.

8. The composite particle of claim 1 , wherein both the first and second anchoring agents are bonded to the surface of the particle.

9. The composite particle of claim 1 , wherein the particle comprises natural or synthetic clay, inorganic metal oxide, latex, or organic materials.

10. The composite particle of claim 1 , wherein the particle comprises silica.

11. The composite particle of claim 1 , wherein the particle is a proppant particulate substrate.

12. A method for forming a composite particle comprising a particle and a polymer at the surface of the polymer, the method comprising:
bonding a polymerization initiator at a surface of the particle, the polymerization initiator comprising an azo-group comprising a first and second end, a first anchoring agent and a second anchoring agent, the first and second anchoring agents being bonded to the first and second ends, respectively, of the azo-group, at least one of the first and second anchoring agents being bonded to the surface of the particle; and
bonding the polymer to the surface of the particle via the polymerization initiator.

13. The method of claim 12 , wherein the polymer is bonded to the surface of the particle via a “grafting from” process.

14. The method of claim 12 , wherein the polymer is bonded to the surface of the particle via a “grafting to” process.

15. The method of claim 12 , wherein the polymerization initiator has the general structure of:
X 1 —R 1 -A 1 -N═N-A 2 -R 2 —X 2

in which
A 1 and A 2 are the same as or different from one another and each comprise an attachment group,
R 1 and R 2 are the same as or different from one another and each comprise a linkage group,
X 1 and X 2 are the same as or different from one another and each comprise the first and second anchoring agents, respectively.

16. The method of claim 15 , wherein A 1 and A 2 have the general structure:

in which
R 3 and R 4 independently comprise H, CN, CH 3 , COOR 6 (R 6 ═H or alkyl), or C 2 H 5 ; and
R 5 is an alkyl group.

17. The method of claim 15 , wherein R 1 and R 2 independently comprise a carbonyl-containing linkage, an amine-containing linkage, a thiol-containing linkage, a phosphonate linkage, an epoxy linkage, an alkene-containing linkage, or are a bond.

18. The method of claim 15 , wherein X 1 and X 2 each independently comprise a thiol group, a phosphonate group, or a halogen.

19. The method of claim 12 , comprising bonding at least one of the first and second anchoring agents to the surface via thiozoline reactivity or via succinimide reactivity.

20. The method of claim 12 , comprising bonding the polymerization initiator to the surface via both the first and second anchoring agents.

Assignees

• Univ South Carolina

Inventors

• Viswanath Anand
• Benicewicz Brian C
• Bell Michael H

Classifications

• C08F120/56

  Acrylamide; Methacrylamide · CPC title

• C08F120/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• C08G2261/418

  Ring opening metathesis polymerisation [ROMP] · CPC title

• C08F4/04 Primary

  Azo-compounds · CPC title

• C08F292/00 Primary

  Macromolecular compounds obtained by polymerising monomers on to inorganic materials · CPC title