Polymerization process with catalyst reactivation
View Patent ↗Polymerization processes of the present invention comprise low catalyst concentration. Embodiments include a polymerization process comprising polymerizing free radically (co)polymerizable monomers in a polymerization medium comprising one or more radically (co)polymerizable monomers, a transition metal catalyst complex capable of participating in a one electron redox reaction with an ATRP initiator; a free radical initiator; and an ATRP initiator; (wherein the concentration of transition metal catalyst complex in the polymerization medium is less than 100 ppm). Further embodiments include a polymerization process, comprising polymerizing one or more radically (co)polymerizable monomers in the presence of at least one transition metal catalyst complex; and an ATRP initiator; and a reducing agent; wherein the transition metal catalyst complex is present at less than 10″3 mole compared to the moles of radically transferable atoms or groups present on the ATRP initiator.
1. A polymerization process, comprising:
polymerizing free radically (co)polymerizable monomers in a polymerization medium comprising:
one or more radically (co)polymerizable monomers,
a transition metal catalyst complex capable of participating in a one electron redox reaction with an ATRP initiator;
a free radical initiator; and
an ATRP initiator; wherein the concentration of transition metal in the polymerization medium is less than 100 ppm.
2. The polymerization process of claim 1 , wherein the concentration of transition metal in the polymerization medium is less than 50 ppm.
3. The polymerization process of claim 1 , wherein the concentration of transition metal in the polymerization medium is less than 10 ppm.
4. The polymerization process of claim 1 , wherein the transition metal catalyst complex is a (pseudo)halogen transfer agent.
5. The polymerization process of claim 1 , wherein the radically polymerizable monomers are selected from the group consisting of monomer(s) of the formula:
wherein R 1 and R 2 are independently selected from the group consisting of H, halogen, CN, CF 3 , straight or branched alkyl of from 1 to 20 carbon atoms, unsaturated straight or branched alkenyl or alkynyl of 2 to 10 carbon atoms, unsaturated straight or branched alkenyl of 2 to 6 carbon atoms substituted with halogen, C 3 -C 8 cycloalkyl, phenyl which may optionally have from 1 to 5 substituents on the phenyl ring selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkenyl, C 1 -C 6 -alkoxy, halogen, nitro, carboxy, C 1 -C 6 alkoxycarbonyl, hydroxy protected with a C 1 -C 6 -acyl, cyano and phenyl, heterocyclyl, C(═Y)R 5 , C(═Y)NR 6 R 7 , YCR 6 R 7 R 8 and YC(═Y)R 8 ; where Y may be NR 8 or O; R 5 is alkyl of from 1 to 20 carbon atoms, alkoxy of from 1 to 20 carbon atoms, aryloxy or heterocyclyloxy; R 6 and R 7 are independently H or alkyl of from 1 to 20 carbon atoms, or R 6 and R 7 may be joined together to form an alkylene group of from 2 to 5 carbon atoms, thus forming a 3- to 6-membered ring; and R 8 is H, straight or branched C 1 -C 6 alkyl or aryl; and R 3 and R 4 are independently selected from the group consisting of H, halogen, C 1 -C 6 alkyl and COOR 9 , where R 9 is H, an alkali metal, or a C 1 -C 6 alkyl group; or
R 1 and R 3 may be joined to form a group of the formula (CH 2 ) n′ or a group of the formula C(═O)—Y—C(═O), where n′ is from 2 to 6, the group (CH 2 ) n′ may be substituted with from 1 to 2n′ halogen atoms or C 1 -C 4 alkyl groups, and Y is as defined above; and at least two of R 1 , R 2 , R 3 , and R 4 are H or halogen.
6. The polymerization process of claim 1 , wherein the radically polymerizable monomers are selected from the group consisting of (meth)acrylate esters of C 1 -C 20 , alcohols, acrylonitrile, cyanoacrylate esters of C 1 -C 20 alcohols, didehydromalonate diesters of C 1 -C 6 alcohols, vinyl pyridines, vinyl N—C 1 -C 6 -alkylpyrroles, vinyl oxazoles, vinyl thiazoles, vinyl pyrimidines and vinyl imidazoles, vinyl ketones in which the α-carbon atom of the alkyl group does not bear a hydrogen atom, and styrenes which may bear a C 1 -C 6 -alkyl group on the vinyl moiety and from 1 to 5 substituents on the phenyl ring selected from the group consisting of C 1 -C 6 alkyl, C 1 -C 6 alkenyl, C 1 -C 6 -alkenyl, C 1 -C 6 -alkoxy, halogen, nitro, carboxy, C 1 -C 6 -alkoxycarbonyl, hydroxy protected with a C 1 -C 6 acyl, cyano and phenyl, methyl acrylate, methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, and styrene.
7. The polymerization process of claim 1 , wherein the polymerization medium further comprises a solvent.
8. The polymerization process of claim 1 , wherein the polymerization medium further comprises water and the polymerization process is one of a suspension polymerization process, emulsion polymerization process, a miniemulsion polymerization process, or a microemulsion polymerization process.
9. The polymerization process of claim 1 , wherein the transition metal catalyst complex comprises a ligand.
10. The polymerization process of claim 9 , wherein the stability constant of the transition metal catalyst complex is greater than 10 8 .
11. The polymerization process of claim 10 , further comprising forming a polymer comprising a molecular weight distribution of less than 2.0.
12. The polymerization process of claim 9 , wherein the stability constant of the transition metal complex is less than 10 8 .
13. The polymerization process of claim 12 , further comprising forming a polymer comprising a molecular weight distribution of less than 1.5.
14. The polymerization process of claim 1 , wherein the free radical initiator is added to the polymerization process initially, slowly, sequentially, or continuously during the polymerizing.
15. The polymerization process of claim 1 , wherein the rate of the polymerization reaction is determined at least in part by the free radical initiator.
16. The process of claim 1 , where the value of K atrp for the transition metal catalyst complex is above 10 −8 .