Process for the production of high molecular weight copolymers of diallylammonium monomers and acrylamide monomers in solution

• US 5,110,883 A
• Filed: 03/11/1991
• Issued: 05/05/1992
• Est. Priority Date: 09/12/1988
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Gartner, Herbert A.
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): NAGUMO, MARK
• Application Number:
  US07/667,707
• Time in Patent Office: 421 Days
• Field of Search: 526/307.3, 526/84, 526/87, 528/487
• US Class Current: 526/84
• CPC Class Codes: C02F 1/54 using organic material
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 226/04 Diallylamine
• CPC Class Codes: D21H 21/10 Retention agents or drainage improvers

Abstract

Water-soluble, high molecular weight, linear copolymers of a diallyl ammonium monomer and an acrylamide monomer of various cationicities are prepared by copolymerization of a major portion of the acrylamide monomer via stage-addition in a solvent solution and adding a chain transfer agent at the conclusion of said copolymerization to prevent branching and cross-linking from occurring.

Claims

1. A process for the preparation of a water-soluble, linear copolymer of diallyl ammonium monomer and acrylamide monomer having a uniform diallyl ammonium monomer to acrylamide monomer ratio comprising the steps of:

a) initiating the copolymerization of a stirred mixture of diallyl ammonium monomer with a portion of the total amount of acrylamide monomer required in a solvent solution at a temperature at which copolymerization proceeds;

b) adding to said stirred monomer solution the remaining acrylamide monomer by continuous addition to form a homogeneous gel solution, while maintaining the reaction temperature;

c) after completion of the addition of acrylamide, maintaining the reaction mixture at the polymerization temperature for a period of about 30 minutes to about 1 hour to complete polymerization;

d) after the polymerization is completed homogeneously mixing a chain transfer agent in said gel solution to form a gel mixture;

e) heating said gel mixture to a temperature at which residual monomer undergoes copolymerization; and

f) drying said gel mixture.

2. A process according to claim 1 wherein the diallyl ammonium monomer corresponds to the formula:

##STR3## and the acrylamide monomer corresponds to the formula;

##STR4## wherein R¹ is independently in each occurrence hydrogen or C_1-4 alkyl;

R² is independently in each occurrence hydrogen, a C_1-18 alkyl, C_1-18 alkoxyalkyl or C_1-18 hydroxyalkyl moiety;

R³ is independently in each occurrence hydrogen or a C_1-5 lower alkyl moiety;

R⁴ is independently in each occurrence hydrogen, C_1-18 alkyl, C_1-18 alkoxy alkyl, or C_1-18 hydroxyalkyl; and

Y is an anion.

3. A process as claimed in claim 2, wherein the solvent is water or C₁ -C₄ primary alcohol.

4. A process as claimed in claim 3 wherein the polymerization temperature of steps a) b) and c) are about 20°

to about 50°

C.

5. A process as claimed in claim 4, wherein about 15 to about 17% of the total amount of the acrylamide monomer is added to step (a).

6. A process as claimed in claim 5, wherein the addition of the remaining acrylamide monomer in step (b) is over a period of about 0.5 to about 8 hours.

7. A process as claimed in claim 6, wherein the remaining acrylamide monomer is added in such a manner that a decreasing feed rate is achieved over the period of addition.

8. A process as claimed in claim 7, wherein from about 30 to about 35% of the remaining acrylamide monomer is added during the first quarter of the said addition period, from about 25 to about 30% is added during the second quarter, from about 20 to about 25% is added during the third quarter and from about 15 to about 20% is added during the final quarter.

9. A process as claimed in claim 8, wherein the chain transfer agent is sodium hypophosphite.

10. A process as claimed in claim 8, wherein the heating of step (e) is conducted at about 60°

to about 90°

C. for about 0.1 to about 4.0 hours.

11. A process as claimed in claim 10, wherein the diallyl ammonium monomer to acrylamide monomer ratio is from 5 to 95 mole %.

12. A process as claimed in claim 10, wherein the diallyl ammonium monomer to acrylamide monomer ratio is from 25 to 50 mole %.