Process for making an acrylic monomer having one or more quaternary ammonium groups and its polymers

1. A method for making a monomer having an ethylenically unsaturated group and two or more quaternary ammonium groups per molecule, comprising:

(a) reacting an excess of a monomeric reactant having at least one ethylenically unsaturated group and at least one tertiary amino group per molecule with a halohydroxyalkyl(trialkyl)quaternary ammonium salt, in an aqueous medium,

(b) monitoring the pH of the aqueous medium from at least as early as the time when all reactants have been added to aqueous medium until completion of the reaction, and

(c) adjusting the pH of the aqueous medium to and maintaining the pH of the aqueous medium at a value greater than or equal to 9, from the time, after all reactants have been added to aqueous medium, that the reaction mixture exhibits an apparent pH minimum until completion of the reaction.

2. A method according to claim 1 , wherein a monomer (IV) is made according to Scheme A:

by reacting an excess of a monomer according to structure (I), wherein:

R 1 is a divalent organic linking group, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 2 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms, or a group according to:

wherein

R 12 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 13 and R 14 are each independently alkyl, and

m is an integer of from 1 to 6,

R 3 is H or (C 1 -C 6 )alkyl,

R 4 is H or (C 1 -C 6 )alkyl,

R 5 and R 6 are each independently (C 1 -C 6 )alkyl,

with a haloalkyl(trialkyl)quaternary ammonium salt according to structure (II), wherein:

R 7 is a divalent organic linking group,

R 8 is halo,

R 9 , R 10 and R 11 are each independently alkyl, and

X − is an anion.

3. A method according to claim 1 , wherein a monomer (IV-a) is made according to Scheme A-1:

by reacting an excess of a monomer (I-a) with a haloalkyl(trialkyl)quaternary ammonium salt (II-a) wherein R 8 is halo and X − is an anion.

4. The method of claim 3 , wherein R 8 is chloro and X— is Cl − .

5. A process for making a polymer wherein one or more monomeric units of the polymer each comprise two or more quaternary ammonium groups per monomeric unit, comprising:

(a) making a monomer having an ethylenically unsaturated group and two or more quaternary ammonium groups per molecule by:

(i) reacting an excess of a monomer having at least one ethylenically unsaturated group and at least one tertiary amino group per molecule with a halohydroxyalkyl(trialkyl)quaternary ammonium salt in an aqueous medium,

(ii) monitoring the pH of the aqueous medium from at least as early as the time when all reactants have been added to aqueous medium until completion of the reaction, and

(iii) adjusting the pH of the aqueous medium to and maintaining the pH of the aqueous medium at a value greater than or equal to 9, from the time after all reactants have been added to aqueous medium, that the reaction mixture exhibits an apparent pH minimum until completion of the reaction, and

(b) polymerizing the monomer formed in step (a) in the presence of a polymerization initiator mixture.

6. The method of claim 5 , wherein the polymer is made according to Scheme B:

by polymerizing a monomer according to structure (IV), wherein

R 1 is a divalent organic linking group, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 2 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms, or a group according to:

wherein

R 12 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 13 and R 14 are each independently alkyl, and

m is an integer of from 1 to 6,

R 3 is H or (C 1 -C 6 )alkyl,

R 4 is H or (C 1 -C 6 )alkyl,

R 5 and R 6 are each independently (C 1 -C 6 )alkyl,

R 7 is a divalent organic linking group,

R 8 is halo,

R 9 , R 10 and R 11 are each independently alkyl, and

X − is an anion

in the presence of a polymerization initiator to form a homopolymer according to structure (V), wherein m is an integer of from 2 to about 30,000.

7. The method of claim 5 , wherein the polymer is made according to Scheme C:

by copolymerizing a monomer according to structure (IV), wherein

R 1 is a divalent organic linking group, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 2 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms, or a group according to:

wherein:

R 12 is alkylene, which may optionally be substituted on one or more carbon atoms or interrupted at one or more sites by heteroatoms,

R 13 and R 14 are each independently alkyl, and

m is an integer of from 1 to 6,

R 3 is H or (C 1 -C 6 )alkyl,

R 4 is H or (C 1 -C 6 )alkyl,

R 5 and R 6 are each independently (C 1 -C 6 )alkyl,

R 7 is a divalent organic linking group,

R 8 is halo,

R 9 , R 10 and R 11 are each independently alkyl, and

X − is an anion,

with a co-monomer (VI), wherein:

R 15 is H or (C 1 -C 6 )alkyl, and

R 16 is hydroxyl,

in the presence of a polymerization initiator to form a copolymer according to structure (VII), wherein p and q are each integers of from 1 to about 100,000.

8. The method of claim 7 , wherein a polymer (VII-a) is made according to Scheme C-1:

by reacting acrylic acid (VI-a) with a di-quaternary monomer (IV-a), wherein X— is an anion and wherein m is an integer of from about 800 to 6,000 and n is an integer of from about 400 to 3,000.

9. The method of claim 8 , wherein X— is Cl − .