Initiator for surface-based polymerization and use thereof
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.
1. A polymerization initiator comprising the 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 first and second anchoring agents, respectively, wherein X 1 and X 2 are the same as or different from one another and each independently comprises a thiol group, a phosphonate group, or a halogen.
2. The polymerization initiator of claim 1 , 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 6 ; and
R 5 is an alkyl group.
3. The polymerization initiator of claim 1 , 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.
4. The polymerization initiator of claim 1 , wherein the first anchoring agent and/or the second anchoring agent comprises a thizoline group.
5. The polymerization initiator of claim 1 , wherein the first anchoring agent and/or the second anchoring agent comprises a succinimide group.
6. A substrate comprising a surface and the polymerization initiator of claim 1 bonded to the surface.
7. A polymerization initiator having the following structure:
8. A substrate comprising the polymerization initiator of claim 7 .
9. A polymerization initiator having the following structure:
10. A substrate comprising the polymerization initiator of claim 9 .