Process for the aqueous polymerization of acrylamide

Claim 2

A process for the preparation of a water-soluble, very high molecular weight homopolymer of acrylamide consisting essentially of (A) maintaining at ambient temperature and pressure under aqueous polymerization conditions a mixture comprising water, a catalytic amount of metal ion co-catalyst, about 10 to about 50 percent by weight of said mixture of acrylamide, and a first member of a redox pair, and (B) incrementally adding thereto a minimum effective amount of a second redox pair member, said amount being that sufficient to initiate polymerization under conditions of ambient temperature and pressure and the addition of said second redox pair member being terminated upon initiation of polymerization

Claim 3

The process of claim 1 wherein said process is conducted under aqueous solution polymerization conditions and said metal ion co-catalyst is cuprous copper or ferrous iron.

Claim 4

The process of claim 1 wherein said process is conducted under solution precipitation or aqueous emulsion polymerization conditions.

Claim 5

The process of claim 2 wherein said first member of a redox pair is selected from the group consisting of at least one of sodium bisulfite, sodium sulfite, sodium metabisulfite, and combination of said sodium bisulfite with ethylenediaminetetracetic acid.

Claim 6

The process of claim 4 wherein said second redox pair member is selected from the group consisting of at least one of ammonium persulfate, potassium persulfate, and hydrogen peroxide.

Claim 7

The process of claim 5 wherein said redox pair is ammonium persulfate and sodium metabisulfite, said metal ion is ferrous iron and said polymer has a molecular weight of about 1 million to about 10 million.

Claim 8

The process of claim 2 wherein said first member of a redox pair is selected from the group consisting of at least one of ammonium persulfate, potassium persulfate, and hydrogen peroxide.

Claim 9

The process of claim 7 wherein said second redox pair member is selected from the group consisting of at least one of sodium bisulfite, sodium sulfite, sodium metabisulfite, and combination of said sodium bisulfite with ethylenediaminetetracetic acid.

Claim 10

The process of claim 7 wherein the proportion of said first activator redox pair member is about 0.05 to about 0.3 percent by weight based upon the weight of the monomer.

Claim 11

The process of claim 9 wherein said redox pair is ammonium persulfate and sodium metabisulfate, said metal ion is ferrous iron and said high molecular weight polymer has a molecular weight of about 1 million to about 10 million.

Claim 12

In a process for the preparation of a water-soluble high molecular weight homopolymer of acrylamide monomer by an aqueous solution or emulsion polymerization process conducted at ambient temperatures and pressures without the use of polymerization regulators in the presence of a redox pair catalyst and a metal ion co-catalyst, wherein at least one of said solution, emulsion or monomer is contaminated with small amounts of polymerization inhibiting components, the improvement consisting essentially of maintaining a minimum effective amount of redox catalyst in admixture with about 10 to about 50 percent by weight of said acrylamide monomer, wherein a first member of a redox pair catalyst is admixed with said monomer in the amount of 0.05 to 0.3 percent by weight based upon the weight of said acrylamide monomer, and a polymerization-initiating effective amount of a second member of a redox pair catalyst is added thereto until the initiation of said polymerization begins, said initiation being determined by a 2° C. to 5° C. exotherm and the addition of said second member of a redox pair catalyst being terminated upon initiation of polymerization.

Claim 13

In a process for the preparation of a water-soluble high molecular weight homopolymer of acrylamide monomer by an aqueous solution or emulsion polymerization process conducted at ambient temperatures and pressures without the use of polymerization regulators in the presence of a redox pair catalyst and a metal ion co-catalyst, wherein at least one of said solution, emulsion or monomer is contaminated with small amounts of polymerization inhibiting components, the improvement consisting essentially of maintaining a minimum effective amount of redox catalyst in admixture with about 10 to about 50 percent by weight of said acrylamide monomer, wherein a first member of a redox pair catalyst is admixed with said monomer in the amount of 0.05 to 0.3 percent by weight based upon the weight of said acrylamide monomer, and a polymerization-initiating effective amount of a second member of a redox pair catalyst is added thereto until the initiation of said polymerization begins, said initiation being determined by a 2° C. to 5° C. exotherm and the addition of said second member of a redox pair catalyst being terminated upon initiation of polymerization.

Claim 14

The process of claim 11 wherein said process is an aqueous solution polymerization process wherein said redox pair is selected from the group consisting of ammonium persulphate and sodium metabisulphate, ammonium persulfate and 3,3',3"-nitrilotrispropionamide; sodium bromate and sodium sulfate; sodium persulfate, and sodium bisulfite; potassium persulfate and sodium metabisulfite; ammonium persulfate and sodium bisulfite; ammonium persulfate and sodium metabisulfite; and hydrogen peroxide and thiourea, said metal ion is ferrous iron, and said high molecular weight polymer has a molecular weight of about 1 million to about 10 million.