# US 2013/0158203 A1 · Compositions and method of inhibiting polymerization of vinyl-aryl monomers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0158203 A1 - Document ID: US20130158203A1 - Status: Published application - Kind: A1 - Application number: 13/811,574 - Filed: 2011-07-27 - Published: 2013-06-20 - Earliest claimed: 2010-08-02 - Assignees: Carnegie Mellon University; Dow Global Technologies LLC - Inventors: Nathan T. Kendall; Kishore K. Kar; Mark H. McAdon; Krzysztof Matyjaszewski; Laura Mueller; Charles D. Dukes - Web page: https://patentgrep.com/patent/US20130158203A1 ## CPC - C07C 7/20: Use of additives, e.g. for stabilisation - C08F 2/00: Processes of polymerisation - C08F 12/08: Styrene - C08F 12/36: Divinylbenzene - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract The invention generally relates to a method of inhibiting polymerization of vinyl aryl monomers, a process for increasing number average molecular weight of a polystyrene, and to an inhibitor composition useful therein. ## Claims ### Claim 1 An inhibitor composition comprising a mixture of a vinyl-aryl monomer and a polymerization-inhibiting effective amount of a substituted amidine of formula (I): or a prototropic tautomer thereof, Wherein: Z is 1,3-(C3 or C7)hydrocarbylene or 1,3-(C2-C6)heterohydrocarbylene such that ring (r) is a six-membered ring; benzo-fused substituted six-membered ring wherein Z comprises a 3-atom linker portion having 2 contiguous ring carbon atoms that are fused to the benzo; or 5-membered or 6-membered heteroarylene-fused substituted six-membered ring wherein Z comprises a 3-atom linker portion having 2 contiguous ring carbon atoms that are fused to the 5-membered or 6-membered heteroarylene, wherein when Z is unsubstituted, ring (r) is non-aromatic and when Z is substituted, ring (r) is non-aromatic or aromatic; And (a), (b), or (c): (a) X is NR2a, C(H)R2b, or O; and Each of R1, R2a, and R2b independently is a hydrogen atom, (C1-C20)hydrocarbyl, or (C1-C20)heterohydrocarbyl; (b) X is NR2a; and R1 and R2a are taken together to form ZA, wherein ZA independently is as defined for Z; or (c) X is C(H)R2b; and R1 and R2b independently are taken together to form ZA, wherein ZA independently is as defined for Z; Wherein each heterohydrocarbylene, and heterohydrocarbyl independently comprises carbon atoms, hydrogen atoms, and 1 or 2 heteroatoms wherein each heteroatom independently is O, S, S(O), S(O)2, or N(RN); Wherein each RN independently is a hydrogen atom or unsubstituted (C1-C10)alkyl; Wherein each benzo, heteroarylene, hydrocarbylene, heterohydrocarbylene, hydrocarbyl, and heterohydrocarbyl independently is unsubstituted or substituted with from 1 to 3 substituents RS; and Wherein each RS independently is bonded to a carbon atom and is unsubstituted (C1-C10)alkyl, unsubstituted (C3-C10)cyclo alkyl, unsubstituted (C1-C10)alkyl-O—, —OH, oxo (i.e., ═O), or fluorine atom. ### Claim 2 (depends on 1) The inhibitor composition as in claim 1, wherein Z is 1,3-(C3 or C7)hydrocarbylene, 1,3-(C3 or C7)hydrocarbylene is 1,3-(C3)alkylene, and X is —NR2aR2b such that the substituted amidine of formula (I) is a compound of formula (II): or a prototropic tautomer thereof, Wherein m is an integer of from 0 to 3 and R1 and R2a are as defined in (a) or (b) of claim 1. ### Claim 3 (depends on 2) The inhibitor composition as in claim 2, wherein R1 and R2a are taken together to form a ZA, ZA is 1,3-(C3 or C7)hydrocarbylene; 1,3-(C3 or C7)hydrocarbylene of ZA is a 1,3-(C3)alkylene such that the compound of formula (II) is a compound of formula (IIa): or a prototropic tautomer thereof, wherein n is an integer of form 0 to 3. ### Claim 4 (depends on 3) The inhibitor composition as in claim 3, wherein m and n are each 0 such that the compound of formula (IIa) is compound (g1): or the prototropic tautomer thereof. ### Claim 5 (depends on 3) The inhibitor composition as in claim 3, wherein m and n are each 2 such that the compound of formula (IIa) is compound (g2), (g3), or (g7): or the prototropic tautomer thereof. ### Claim 6 (depends on 2) The inhibitor composition as in claim 2, wherein the compound of formula (II) is any one of compounds (g4) to (g6): or the prototropic tautomer thereof. ### Claim 7 (depends on 1) The inhibitor composition as in claim 1, wherein X is O such that the substituted amidine of formula (I) is a compound of formula (III): or a prototropic tautomer thereof, Wherein m is an integer of from 0 to 3. ### Claim 8 (depends on 7) The inhibitor composition as in claim 7, wherein the compound of formula (III) is compound (i1) or (i2): or the prototropic tautomer thereof. ### Claim 9 (depends on 1) The inhibitor composition as in claim 1, wherein X is C(H)R2b such that the substituted amidine of formula (I) is a compound of formula (IV): or a prototropic tautomer thereof, wherein m is an integer of from 0 to 3 and R1 and R2b are as defined in (a) or (c) of claim 1. ### Claim 10 (depends on 9) The inhibitor composition as in claim 9, wherein the compound of formula (IV) is any one of compounds (c1) to (c3): or the prototropic tautomer thereof. ### Claim 11 (depends on 9) The inhibitor composition as in claim 9, wherein the compound of formula (IV) is compound (c4) or (c5): or the prototropic tautomer thereof. ### Claim 12 (depends on 1) The inhibitor composition as in claim 1, wherein the NH in the substituted amidine of formula (I) is characterizable by a pKa of from 25 to 27. ### Claim 13 (depends on 1) The inhibitor composition as in claim 1, wherein the mixture of the inhibitor composition further comprises one or more vinyl-aryl monomer polymerization inhibitors other than the substituted amidine of formula (I) or prototropic tautomer thereof. ### Claim 14 (depends on 13) The inhibitor composition as in claim 13, wherein the one or more vinyl-aryl monomer polymerization inhibitors other than the substituted amidine of formula (I) or prototropic tautomer thereof comprises molecular oxygen, 2,2,6,6-tetramethylpiperidine-1-oxyl, or a 4-monosubstitiuted 2,2,6,6-tetramethylpiperidine-1-oxyl. ### Claim 15 (depends on 14) The inhibitor composition as in claim 14, wherein the one or more vinyl-aryl monomer polymerization inhibitors other than the substituted amidine of formula (I) or prototropic tautomer thereof comprises molecular oxygen and either 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl or 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl. ### Claim 16 (depends on 14) The inhibitor composition as in claim 14 wherein the molecular oxygen functions in such a way so as to increase vinyl-aryl polymerization-inhibiting effectiveness of the inhibitor composition compared to vinyl-aryl polymerization-inhibiting effectiveness of the inhibitor composition lacking molecular oxygen. ### Claim 17 (depends on 1) The inhibitor composition as in claim 1, or the prototropic tautomer thereof, wherein the inhibitor composition substantially lacks 4,6-dinitro-2-(1-methylpropyl)-phenol, copper, or both. ### Claim 18 (depends on 1) The inhibitor composition as in claim 1, or the prototropic tautomer thereof, wherein the vinyl-aryl monomer is styrene, a divinylbenzene, or a mixture of two or more thereof. ### Claim 19 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18) A method of inhibiting polymerization of a vinyl-aryl monomer, the method comprising contacting a vinyl-aryl monomer in need of polymerization inhibition treatment with a polymerization-inhibiting effective amount of the substituted amidine of formula (I) as described in any one of claims 1 to 18, or the prototropic tautomer thereof, wherein the contacting is performed in such a way that polymerization of the vinyl-aryl monomer is inhibited. ### Claim 20 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18) A process for building molecular weight of a polystyrene, the process comprising contacting a first polystyrene with a nitroxide radical source and a polymerization-inhibiting effective amount of the substituted amidine of formula (I) as described in any one of claims 1 to 18, or the prototropic tautomer thereof, wherein the contacting is performed in such a way that the styrene monomer reacts with the first polystyrene so as to form a second polystyrene such that number average molecular weight of the second polystyrene is greater than number average molecular weight of the first polystyrene.