Rendering porous structures impermeable by treatment with gellable amine polymers
AssigneeThe Dow Chemical Company
InventorRichard J. Pilny
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Abstract
Aqueous solutions of amide polymers such as polyacrylamide when treated with small amounts of a water-soluble polyaldehyde at an alkaline pH react to form film gels within a short time at ambient temperature. Such gels are usefully employed to plug porous subterranean formations, for grouting of leaking soil pipes or wells, and to otherwise render porous structures impermeable to the passage of liquids such as water.
Claims13
A method for rendering a porous structure impermeable which comprises treating the porous structure with a gellable aqueous composition comprising an aqueous medium having dispersed therein an amide polymer and an aliphatic polyaldehyde in proportions such that under ambient temperatures and at an alkaline pH greater than 7.5 the gellable composition upon being forced into and over the porosities of the structure reacts to form a gel capable of rendering said structure impermeable to the passage of aqueous liquids.
In a method for grouting sewers and water wells which comprises locating a leaking area in a subterranean conduit, isolating said leaking area with packing devices and pumping a gellable composition into and over said area, the improvement which comprises preparing said gellable composition by admixing an aqueous solution of at least five weight percent of a water-soluble amide polymer with sufficient of an aqueous solution of a water-soluble aliphatic dialdehyde to provide from about 0.01 to about 0.067 mole of dialdehyde per mole of amide monomer combined in said polymer and with sufficient of an inorganic alkaline reagent to produce a pH of greater than 7.5.
Dependencies are inferred from the claim text.