Cationic silicone surfactants and method of preparing same

1. A cationic surfactant having general formula (I):

[Z-D-N(-D 1 -NR 1 3 + ) a (R) 2-a ][X − ] a   (I),

wherein Z is a siloxane moiety comprising an inorganic silicon-oxygen-silicon group, with organosilicon and/or organic side groups attached to the silicon atoms; D is a covalent bond or a divalent linking group; D 1 is a divalent linking group; R is H or an unsubstituted hydrocarbyl group having from 1 to 4 carbon atoms; each R 1 is an independently selected unsubstituted hydrocarbyl group having from 1 to 4 carbon atoms; subscript a is 1 or 2; and each X is an anion.

2. The cationic surfactant of claim 1 , wherein: (i) D is the divalent linking group; (ii) subscript a is 1 and R is H; or (iii) a combination thereof.

3. The cationic surfactant of claim 1 , wherein the siloxane moiety Z has the formula:

where each R 3 is independently selected from R 2 and —OSi(R 4 ) 3 , with the proviso that at least one R 3 is —OSi(R 4 ) 3 ; where each R 4 is independently selected from R 2 , —OSi(R 5 ) 3 , and —[OSiR 2 2 ] m OSiR 2 3 ; where each R 5 is independently selected from R 2 , —OSi(R 6 ) 3 , and —[OSiR 2 2 ] m OSiR 2 3 ; where each R 6 is independently selected from R 2 and —[OSiR 2 2 ] m OSiR 2 3 ; where 0≤m≤100; and where each R 2 is independently a substituted or unsubstituted hydrocarbyl group.

4. The cationic surfactant of claim 3 , wherein each R 3 is —OSi(R 4 ) 3 , where R 4 is independently selected and as defined above.

5. The cationic surfactant of claim 1 , wherein the siloxane moiety Z has one of the following structures (i)-(iv):

6. The cationic surfactant of claim 1 , wherein D is the divalent linking group, and wherein: (i) the divalent linking group D is a branched or linear alkylene group; or (ii) the divalent linking group D has formula -D 2 -NY-D 2 -, where each D 2 is an independently selected divalent linking group, and Y is H or -(D 1 -NR 1 3 )+X − , where D 1 , R 1 , and X are as defined above.

7. The cationic surfactant of claim 6 , wherein the divalent linking group D has formula -D 2 -NY-D 2 -, where each D 2 and Y are as defined above, and wherein: (i) each D 2 is an independently selected alkylene group having from 1 to 8 carbon atoms; (ii) Y is -(D 1 NR 1 3 ) + X − , where D 1 , R 1 , and X are as defined above; or (iii) both (i) and (ii).

8. The cationic surfactant of claim 1 , wherein: (i) each D 1 is —CH 2 CH(OH)CH 2 —; (ii) each R 1 is methyl; (iii) each X is Cl; or (iv) any combination of (i) to (iii).

9. A method of preparing a cationic surfactant, said method comprising:

reacting (A) an amine compound and (B) a quaternary ammonium compound to give the cationic surfactant;

wherein the amine compound (A) has the general formula (II):

Z-D-NHR  (II),

where Z is a siloxane moiety comprising an inorganic silicon-oxygen-silicon group, with organosilicon and/or organic side groups attached to the silicon atoms, D is a covalent bond or a divalent linking group, and R is H or an unsubstituted hydrocarbyl group having from 1 to 4 carbon atoms;

wherein the quaternary ammonium compound (B) has the general formula (III):

[R 8 NR 1 3 ] + [X] −   (III),

where R 8 is an amine-reactive group; each R 1 is an independently selected unsubstituted hydrocarbyl group having from 1 to 4 carbon atoms; and X is an anion; and

wherein the cationic surfactant is the cationic surfactant of claim 1 .

10. The method of claim 9 , wherein: (i) the siloxane moiety Z the has the formula:

where each R 3 is independently selected from R 2 and —OSi(R 4 ) 3 , with the proviso that at least one R 3 is —OSi(R 4 ) 3 ; where each R 4 is independently selected from R 2 , —OSi(R 5 ) 3 , and —[OSiR 2 2 ] m OSiR 2 3 ; where each R 5 is independently selected from R 2 , —OSi(R 6 ) 3 , and —[OSiR 2 2 ] m OSiR 2 3 ; where each R 6 is independently selected from R 2 and —[OSiR 2 2 ] m OSiR 2 3 ; where 0≤m≤100; and where each R 2 is independently a substituted or unsubstituted hydrocarbyl group; (ii) D is the divalent linking group; (iii) R is H; or (iv) any combination of (i) to (iii).

11. The method of claim 9 , wherein D is the divalent linking group, and wherein: (i) the divalent linking group D is a branched or linear alkylene group; or (ii) the divalent linking group D has formula -D 2 -NH-D 2 -, where each D 2 is an independently selected divalent linking group.

12. The method of claim 9 , wherein: (i) R 8 is an epoxypropyl group; (ii) each R 1 is methyl; (iii) each X is Cl; or (iv) any combination of (i) to (iii).

13. A cationic surfactant prepared in accordance with the method of claim 9 .