Blends of acrylamide polymers and Mannich bases

A composition that is substantially anhydrous and made by blending water soluble Mannich base of a low molecular weight, Mannich base-forming compound selected from phenols, ketones and amides and having molecular weight below 1,000 contaminated with water, with a material that can be hydrated by the contaminating water and with substantially dry, water soluble, high molecular weight acrylamide polymer.

A method of making an anhydrous composition that comprises water soluble, high molecular weight, acrylamide polymer and water soluble Mannich base of a Mannich base-forming compound selected from phenols, ketones and amides and having molecular weight below 1,000 comprising gel polymerising acrylamide in intimate admixture with an inorganic hydrate that reversibly undergoes dehydration during polymerisation with absorption of heat of polymerisation, comminuting and drying the resultant gel while the hydrate remains in anhydrous or low hydrate form and blending the comminuted product with the said low molecular weight Mannich base while that is contaminated with water and absorbing the contaminated water by the anhydrous or low hydrate form of the inorganic hydrate.

A method of making an aqueous solution of a Mannich base of a water soluble high molcular weight acrylamide polymer comprising dissolving into water the acrylamide polymer and a water soluble low molecular weight Mannich base of urea and allowing the said low molecular weight Mannich base to react with the acrylamide polymer.