Control agents for living-type free radical polymerization, methods of polymerizing and polymers with same
Control agents that have a nitrogen-nitrogen bond covalently bonded to a thiocarbonyl moiety are provided for living-type free radical polymerization of a wide variety of monomers. These control agents provide superior properties for control of the polymerization and/or the properties of the polymers obtained and/or the monomers that may be polymerized. In some embodiments, a bulky group is pendant off the activated thiocarbonyl portion of the control agents. Multifunctional control agents provide the opportunity for a variety of structurally unique polymers, including block copolymers, stars and hyper-branched polymers.
1. A compound characterized by the formula:
wherein R 1 is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, and combinations thereof, with the proviso that R 1 is not methyl;
R 2 and R 3 are each independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, and combinations thereof;
R 4 is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, and combinations thereof;
R 4 combines with R 2 and/or R 3 to form a ring structure, with said ring having from 3 to 50 non-hydrogen atoms.
2. The compound of claim 1 , wherein R 1 is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted heterocyclyl, optionally substituted alkylthio, optionally substituted amino and optionally substituted polymer chains.
3. The compound of claim 2 , wherein R 1 is selected from the group consisting of —CH 2 Ph, —CH(CH 3 )CO 2 CH 2 CH 3 , —CH(CO 2 CH 2 CH 3 ) 2 , —C(CH 3 ) 2 CN and —C(CH 3 ) 2 Ph.
4. The compound of claim 1 , wherein R 2 is hydrogen and R 3 and R 4 form a five member substituted heterocycle.
5. The compound of claim 4 , wherein the five member substituted heterocycle comprises a methyl substituent.
6. A compound characterized by the formula:
wherein R 1 is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, and combinations thereof;
R 2 is hydrogen;
R 4 is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, and combinations thereof; and
R 4 combines with R 3 to form a ring structure, with said ring having from 3 to 50 non-hydrogen atoms.
7. The compound of claim 6 , wherein R 1 is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted heterocyclyl, optionally substituted alkylthio, optionally substituted amino and optionally substituted polymer chains.
8. The compound of claim 7 , wherein R 1 is selected from the group consisting of —CH 2 Ph, —CH(CH 3 )CO 2 CH 2 CH 3 , —CH(CO 2 CH 2 CH 3 ) 2 , —C(CH 3 ) 2 , —C(CH 3 ) 2 CN and —C(CH 3 ) 2 Ph.
9. The compound of claim 6 , wherein R 4 and R 3 combine to form a substituted heterocycle.
10. The compound of claim 9 , wherein the heterocycle comprises at least one methyl substituent.
11. The compound of claim 9 , wherein the heterocycle comprises at least one oxygen substituent.
12. The compound of claim 9 , wherein the heterocycle comprises 5 non-hydrogen atoms.
13. The compound of claim 12 , wherein the heterocycle further comprises two methyl substituents.
14. The compound of claim 12 , wherein the heterocycle further comprises an oxygen substituent.
15. The compound of claim 13 , wherein the heterocycle further comprises a methyl substituent.