Self-repairing cement polymer composites and processes of making and using same
New cement-polymer composites and processes of making and using are detailed. One exemplary cement-polymer composite include a Portland cement, an epoxide polymer, a thiol-containing crosslinking agent, and an optional phase separation inhibitor. These composites are dynamically self-healing, mechanically robust, and thermally stable in high temperature environments and can be expected to increase service lifetimes in various applications including energy producing wellbores.
1. A method of forming a self-repairing cement-polymer composite matrix, comprising the steps of:
introducing a cement-polymer composite-forming slurry comprising a cement-containing material, an epoxide polymer and/or epoxide oligomers thereof, a crosslinking agent, and an optional phase-separation inhibitor combined in an aqueous medium to a receiving location so as to contact structures and materials therein;
curing the composite-forming slurry to form a self-repairing and self readhering cement-polymer composite matrix comprising chemical bonds between compounds therein and the structures and materials in the receiving location; and
dynamically self-repairing structural breaches in the composite matrix by reforming chemical bonds between compounds therein and/or with the structures and materials bonded thereto restoring at least partial strength thereto and/or reducing permeability by up to about 90% therein.
2. The method of claim 1 further including the step of forming the cement-polymer composite-forming slurry by combining the cement-containing material, the epoxide polymer and/or epoxide oligomers, the crosslinking agent, and the optional phase-separation inhibitor in the aqueous medium prior to introducing the composite-forming slurry into the receiving location.
3. The method of claim 1 , wherein the epoxide polymer comprises an epoxy-terminated polysulfide polymer.
4. The method of claim 1 , wherein the epoxide polymer comprises a terminal epoxide group.
5. The method of claim 1 wherein the crosslinking agent includes a functional group selected from the group consisting of hydrogen; alcohol; thiol; ether; ester; amine; amide; and combinations thereof.
6. The method of claim 1 wherein the phase separation inhibitor is a polymer having at least one terminal functional group reactive with the epoxide polymer and/or epoxide oligomers selected from the group consisting of amines; thiols; epoxides; alcohols; amides; carboxylates; carbonyls; and combinations thereof.
7. The method of claim 1 wherein the phase separation inhibitor is selected from poly(ethylene glycol) diglycidyl ethers (PEO); poly(ethylene) glycols (PEG); bisphenol diglycidyl ethers (BPA); and combinations thereof.
8. The method of claim 1 wherein the epoxide polymer comprises an epoxy-terminated polysulfide polymer; the crosslinking agent is a tetrathiol; and the phase separation inhibitor is a PEO surfactant.
9. The method of claim 1 wherein the self-repairing step includes a process selected from thiol metathesis; thiolate exchange; epoxide ring opening; metal coordination; ionic coordination; Diels-Alder bonding; and combination thereof.