WO2013148722A1 - Régulation de la polymérisation radicalaire vivante par la lumière - Google Patents

Régulation de la polymérisation radicalaire vivante par la lumière Download PDF

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WO2013148722A1
WO2013148722A1 PCT/US2013/033933 US2013033933W WO2013148722A1 WO 2013148722 A1 WO2013148722 A1 WO 2013148722A1 US 2013033933 W US2013033933 W US 2013033933W WO 2013148722 A1 WO2013148722 A1 WO 2013148722A1
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light
polymer chains
radical polymerization
monomers
polymerization process
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PCT/US2013/033933
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Craig J. Hawker
Brett P. Fors
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The Regents Of The University Of California
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/46—Polymerisation initiated by wave energy or particle radiation
    • C08F2/48—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2438/00—Living radical polymerisation

Definitions

  • the invention relates to controlled radical polymerizations utilizing photoredox catalyst that are mediated, as well as regulated, by light.
  • NMP nitroxide-mediated radical polymerization
  • ATRP atom transfer radical polymerization
  • RAFT reversible addition fragmentation chain transfer polymerization
  • this polymerization reaction can be turned “on” and “off by adjusting parameters such as applied current, potential, and total charge passed.
  • parameters such as applied current, potential, and total charge passed.
  • the invention disclosed herein involves a radical polymerization process that is easily and precisely controllable via light.
  • the characteristics of this polymerization process make it a versatile platform for the preparation of a wide variety of functional materials that can be adapted for use in a number of contexts.
  • the invention disclosed herein has a number of embodiments that include methods, materials and systems for making and using polymers formed by these photo-controlled polymerization processes.
  • the polymer compositions of the invention include a variety of polymeric structures including for example, block copolymers and the like.
  • Illustrative embodiments of the invention include compositions of matter comprising a plurality of polymer chains, wherein the polymer chains undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • the composition typically comprises monomers that form the polymer chains in the radical polymerization process, an initiator that reacts with the monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the relative amounts of the reagents used to form these polymers can be controlled in order to control one or more aspects of the polymer molecules such as the polydispersity of the polymer chains.
  • a reagent such as the initiator or the photoredox catalyst is present in the composition in a sub-stoichiometric amount.
  • the amount of catalyst is less than 20 mol % but more than 0.00001 mol % relative to the amount of monomer used.
  • Illustrative embodiments of the invention include methods for making polymers using a photo-controlled radical polymerization process.
  • An illustrative embodiment is a method of forming polymer chains that are capable of undergoing a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light. This method comprises the steps of combining together a reaction mixture comprising monomers that can form the polymer chain subunits in a radical polymerization process, an initiator that reacts with monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the reagents used in these methods are selected so that exposing this reaction mixture to light initiates a reversible and photo-controlled radical polymerization process, one that produces polymer chains characterized by their ability to reversibly activate chain growth in the presence of light and reversibly deactivate chain growth in the absence of light.
  • a property of the polymer chains is controlled by controlling the relative amounts of reagents used in the reaction mixture and/or by controlling an amount of time that compounds the reaction mixture are exposed to light; and/or controlling an intensity of light that reaches the reaction mixture.
  • Yet another embodiment of the invention is a polymerization system comprising monomers that form polymer chain subunits in a radical polymerization process, an initiator that reacts with monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the reagents and reaction conditions are selected so that monomers, initiator and catalyst combined in a reaction mixture will form a plurality of polymer chains that undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • the polymerization system includes a solvent in which the monomers, initiator and catalyst can be combined in the reaction mixture and/or a reaction vessel in which the monomers, initiator and catalyst can be combined so as to form the plurality of polymer chains and/or a light source, wherein the amount and/or intensity of light produced by the light source is controllable and/or a filter that modulates the intensity of the light from the light source.
  • the polymerization system is in the form of a kit, for example one including a plurality of containers that hold the reagents used to form the polymers.
  • the kit includes one or more reagents used to form polymers (e.g. initiators, monomers, catalysts, solvents and the like) as well as articles useful to control polymer growth, for example a controllable light source, one or more light filters and the like.
  • Figure 1 diagram showing aspects of a polymerization scheme that allows, for example, temporal and spatial control over radical polymerization reactions using light.
  • Figure 2 graphs showing the polymerization of MM A using catalyst 1 while cycling the reaction's exposure to visible light.
  • A Conversion vs. time
  • B time of light exposure vs. ln([M] 0 /[M] t ), with [M] 0 and [M] t being the concentrations of monomers at time points zero and t, respectively;
  • C conversion vs. M n ( ⁇ ) and conversion vs. M w /M n ( ⁇ ).
  • Figure 3 diagram showing synthesis of a poly(methyl methacrylate)- ⁇ - (benzyl methacrylate) diblock copolymer.
  • B graphed data from a size exclusion chromatogram with the gray and black traces corresponding to 4 and 3, respectively.
  • Figure 4 a schematic of a proposed mechanism of a visible-light-mediated radical polymerization using an Ir-based photoredox catalyst.
  • P n polymer chain.
  • Figure 5 a schematic and Table showing data on molecular weight and polydispersities for the visible-light-mediated polymerization of methyl methacrylate using [Ir(ppy) 3 ].
  • Figure 6 a schematic and Table showing data on the synthesis of random copolymers and the homopolymer of methacrylic acid (MAA).
  • Figure 7 photographic image of illustrative equipment used in polymerization reactions.
  • Figure 8 graphed data showing fluorescence of a 0.13 mM solution of 1 in DMF with varying concentrations of methyl methacrylate (MMA) or ethyl a- bromophenylacetate (initiator).
  • MMA methyl methacrylate
  • initiator ethyl a- bromophenylacetate
  • Figure 9 graphed data showing fluorescence of a 0.13 mM solution of 1 in DMF with varying concentrations of methyl methacrylate (MMA).
  • Figure 10 graphed data showing fluorescence of a 0.13 mM solution of 1 in DMF with varying concentrations of ethyl a-bromophenylacetate (initiator).
  • Figure 11 graphed data showing conversion vs time for the polymerization of methyl methacrylate.
  • Figure 12 graphed data showing conversion vs number average molecular weight (circle) and conversion vs the molecular weight distribution (triangle) for the polymerization of methyl methacrylate.
  • Figure 13 drawings of illustrative initiators that can be used in embodiments of the invention.
  • Figure 14A-C show drawings of illustrative photoredox catalysts that can be used in embodiments of the invention
  • Figure 14D-F show drawings of illustrative ligands that can be used in embodiments of the invention.
  • a new controlled radical polymerization which is adapted for controlled polymer formation and which displays an unprecedented response to activation and deactivation of polymerization through external visible light stimulation is disclosed herein.
  • the advantages of this approach lie in its highly responsive nature, facile reaction setup, use of only ppm levels of catalyst, and excellent functional group tolerance.
  • this photocontrolled radical polymerization offers a versatile platform for the preparation of functional materials with applications in sustainability, electronics, and health.
  • a number of illustrative and working embodiments of the invention and/or methods and materials that can be used with embodiments of the invention are discussed below.
  • the invention disclosed herein has a number of embodiments that include methods, materials and systems for making and using polymers using a photo- controlled radical polymerization process.
  • Illustrative embodiments of the invention include methods of forming polymers using a photo-controlled radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • this photo-controlled radical polymerization process can be activated and/or deactivated multiple times simply by exposing the polymerization reactants to light and/or shielding the polymerization reactants from light.
  • a small amount of polymer chain termination may be occurring in these radical polymerization processes, they nonetheless exhibit characteristics of a "living polymerization process" (i.e.
  • Controlled and living polymerization processes are known in the art and described, for example, in A. H. E. Miiller, K. Matyjaszewski, Controlled and Living Polymerizations: Methods and Materials, Wiley- VCH, Weinheim, 2009.
  • a polymerization process of the invention comprises the steps of forming a plurality of polymer chains by forming a reaction mixture that includes the monomers that form polymer chain subunits in the radical polymerization process, an initiator that reacts with the monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the reagents are selected so that the polymer chains undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • reagent use can be controlled in these methods so that, for example, a reagent such as the initiator or photoredox catalyst is present in the reaction mixture in sub-stoichiometric amounts and serves as a process limiting reagent.
  • a reagent such as the initiator or photoredox catalyst
  • the radical polymerization process is initiated in the light exposed areas so that polymers are formed.
  • Methods of the invention allow precise control of polymer growth so as to form polymers having selected lengths and/or selected molecular weights (e.g. within selected mw ranges) and/or selected molecular weight distributions and/or selected architectures.
  • polymer chains are formed to have a structure selected from a group consisting of block copolymers; random copolymers; gradient copolymers; periodic polymers; alternating polymers; statistical polymers; linear polymers; branched polymers; star polymers; brush polymers; comb polymers; and graft polymers.
  • polymer chain lengths in a reaction mixture are controlled by controlling an amount of time that the reaction mixture is exposed to light; and/or by controlling an intensity of light that reaches the reaction mixture.
  • Embodiments of the invention can comprise exposing a reaction mixture to light multiple times in order to precisely tailor one or more characteristics of a polymer composition.
  • a reaction mixture is first exposed to light for a period of time so that the radical polymerization process is activated; followed by a step in which this reaction mixture is protected from light exposure for a period of time so that the radical polymerization process is deactivated; and then re-exposing the reaction mixture to light for a period of time so that the radical polymerization process is re-activated etc.
  • the methods disclosed herein can be used to form polymeric materials that have a number of desirable qualities including for example, a relatively low polydispersity.
  • the polydispersity index (PDI) is a measure of the distribution of molecular mass in a given polymer sample.
  • the PDI calculated is the weight average molecular weight (Mw) divided by the number average molecular weight (Mn).
  • Mw weight average molecular weight
  • Mn number average molecular weight
  • polymer chain growth is controlled so that the polymer chains in a reaction mixture that are exposed to a specific amount of light (e.g. a specific frequency of light and/or a specific wavelength of light and/or light having a specific photon energy level and/or a specific power of light) exhibit a polydispersity index such that M w /M n is between 1.0 and 2.0 (e.g. 1.05 and 1.5).
  • a specific amount of light e.g. a specific frequency of light and/or a specific wavelength of light and/or light having a specific photon energy level and/or a specific power of light
  • M w /M n is between 1.0 and 2.0 (e.g. 1.05 and 1.5).
  • different portions of regions of a reaction mixture are exposed to different amounts of light and, when examined in aggregate, the polydispersity index of the polymer chains is greater than 2.0, and can be, for example, greater than 5, 10, 25, 50, 100, 150 or 200.
  • One embodiment of the invention is a composition comprising a plurality of polymer chains that undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • the reagents of the composition allow the polymer chains to undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • a polymerization process can be initiated and/or deactivated multiple times simply by exposing the polymerization reactions to light and/or shielding the polymerization reactions from light.
  • compositions having various polymeric structures including for example, block copolymers, random copolymers; gradient copolymers; periodic polymers; alternating polymers; statistical polymers; linear polymers; branched polymers; star polymers; brush polymers; comb polymers; graft polymers and the like.
  • Illustrative embodiments of the invention include compositions of matter comprising a plurality of polymer chains, wherein the polymer chains undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • the composition typically comprises monomers that form the polymer chains in the radical polymerization process, an initiator that reacts with the monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the relative amounts of the reagents used to form these polymers can be controlled in order to control one or more aspects of the polymer molecules such as the polydispersity of the polymer chains.
  • a reagent such as the initiator or the photoredox catalyst is present in the composition in a sub- stoichiometric amount.
  • the amount of initiator added to a reaction mixture is controlled to control the molecular weight of the final polymer product.
  • the amount of catalyst is less than 20 mol % but more than 0.00001 mol % relative to the amount of monomer used.
  • the monomers comprise an alkene moiety.
  • the monomer comprises an acrylate, a methacrylate, a styrene, a vinyl acetate, a vinylpyridine or a vinyl chloride.
  • the initiator comprises a halide or a pseudo halide.
  • the initiator comprises a xanthate, a thioesters, a thionoester, a dithioesters, a trithioesters or a nitroxide.
  • the catalyst comprises a transition metal photoredox catalyst having a transition metal selected from the group consisting of Ir, Co, Fe, Rh, Pt, Pd, Mn, Os, Eu, Cr, Cu, Al, Ti, Zn, Cd and Ru.
  • M w the weight average molecular weight of the plurality of polymer chains
  • M n the number average molecular weight of the plurality of polymer chains.
  • Embodiments of the invention include forming macromolecular structures by cross-linking the polymer compositions.
  • Illustrative embodiments of the invention include methods for making polymers using a photo-controlled radical polymerization process.
  • An illustrative embodiment is a method of forming polymer chains that are capable of undergoing a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light. This method comprises the steps of combining together a reaction mixture comprising monomers that can form the polymer chain subunits in a radical polymerization process, an initiator that reacts with monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the reagents used in these methods are selected so that exposing this reaction mixture to light initiates a reversible and photo-controlled radical polymerization process, one that produces polymer chains characterized by their ability to reversibly activate chain growth in the presence of light and reversibly deactivate chain growth in the absence of light.
  • the method comprises the sequential steps of exposing compounds combined in a reaction mixture to light for a period of time so that the radical polymerization process is activated and then protecting this reaction mixture from light exposure for a period of time so that the radical polymerization process is deactivated, and then re-exposing this reaction mixture to light for a period of time so that the radical polymerization process is re-activated etc. etc.
  • a property of the polymer chains is controlled by controlling the relative amounts of reagents used in the reaction mixture and/or by controlling an amount of time that compounds the reaction mixture are exposed to light; and/or controlling an intensity of light that reaches the reaction mixture.
  • Yet another embodiment of the invention is a polymerization system comprising monomers that form polymer chain subunits in a radical polymerization process, an initiator that reacts with monomers in the radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains, and a photoredox catalyst.
  • the reagents and reaction conditions are selected so that monomers, initiator and catalyst combined in a reaction mixture will form a plurality of polymer chains that undergo a radical polymerization process that is reversibly activated in the presence of light and reversibly deactivated in the absence of light.
  • the polymerization system includes a solvent in which the monomers, initiator and catalyst can be combined in the reaction mixture and/or a reaction vessel in which the monomers, initiator and catalyst can be combined so as to form the plurality of polymer chains and/or a light source, wherein the amount and/or intensity of light produced by the light source is controllable and/or a filter that modulates the intensity of the light from the light source.
  • Embodiments of the invention also provide articles of manufacture and kits for forming the disclosed polymers.
  • the kit includes one or more reagents used to form the disclosed polymers (e.g. monomers, initiators, catalysts, solvents and the like) as well as articles useful to control polymer growth, for example a controllable light source, one or more light filters and the like.
  • the polymerization system is in the form of a kit, for example one including a plurality of containers that hold the reagents used to form the polymers.
  • the kit includes one or more reagents used to form polymers (e.g. initiators, monomers, catalysts, solvents and the like) as well as articles useful to control polymer growth, for example a controllable light source, one or more light filters and the like.
  • polymerization reagents can be selected to modulate aspects of these polymerization reactions. These include monomers, initiators, catalysts, and solvents. Reactions with these compounds can then be carried out on a variety of vessels, for example those of the type shown in Figure 7. Moreover, such reactions are typically carried out in a solvent. As is known in the art, the solvent component of a solution is present in the greatest amount and is the substance in which the solutes are dissolved.
  • Embodiments of the invention can be adapted for use with a variety of solvents known in the art, for example dimethyl formamide (DMF), toluene, 1,4-dioxane, xylene, anisole, DMSO, Tetrahydrofuran (THF), water, methanol, acetonitrile, chloroform and the like.
  • one or more reactants in the polymerization process e.g. a monomer
  • the amounts of monomer present in the reaction mix are greater than the amounts of DMF present in the reaction mix.
  • an initiator reacts with the monomers in a radical polymerization process to form an intermediate compound capable of linking successively with the monomers to form the polymer chains.
  • the number of growing polymer chains can be determined by the initiator. The faster the initiation, the fewer terminations and transfers, the more consistent the number of propagating chains leading to narrow molecular weight distributions.
  • Organic halides can be used as initiators in processes of the invention.
  • Initators for in common embodiments of the invention typically comprise alkyl halides or pseudo halides.
  • Alkyl halides such as alkyl bromides are more reactive than alkyl chlorides.
  • the shape or structure of an initiator can be selected to influence the architecture of a polymer. For example, initiators with multiple alkyl halide groups on a single core can lead to a star-like polymer shape.
  • Initiators other than alkyl halide or pseudo halide that can be used in embodiments of the invention include, but are not limited to, xanthates, thioesters, thionoesters, dithioesters, trithioesters, and nitroxides.
  • Illustrative initiators other than ethyl a-bromophenylacetate that can be used in embodiments of the invention include but are not limited to those shown in Figure 13.
  • monomers encompass a class of compounds, mostly organic, that can react with other molecules of the same or other compound to form very large molecules, or polymers.
  • Monomers that are typically used in polymerization reactions include molecules with substituents that can stabilize the propagating radicals; for example, styrenes, (meth)acrylates, (meth)acrylamides, and acrylonitrile.
  • Embodiments of the invention can be used to form polymers of high number average molecular weight and a narrow polydispersity index when the concentration of the propagating radical balances the rate of radical termination.
  • Monomers that undergo radical polymerization in the disclosed process include but are not limited to typical alkene monomers that undergo traditional radical polymerization, such as but not limited to, methyl methacrylate, styrenes, acrylates, methyl acrylate, acrylonitrile, vinyl acetate, vinylpyridine, methacrylic acid, tert-butyl methacrylate, benzyl methacrylate, tert-butyl acrylate, benzyl acrylate, vinyl chloride, acrylamides, acrylic acid.
  • typical alkene monomers that undergo traditional radical polymerization such as but not limited to, methyl methacrylate, styrenes, acrylates, methyl acrylate, acrylonitrile, vinyl acetate, vinylpyridine, methacrylic acid, tert-butyl methacrylate, benzyl methacrylate, tert-butyl acrylate, benzyl acrylate, vinyl chloride, acrylamides, acrylic acid
  • Reactive functional groups on monomers include, but are not limited to, carboxylic acids, epoxides, amines, amides, alcohols, ketones, aldehydes, alkynes, alkenes, fluorides, chlorides, bromides, iodides, ethers, esters, hyroxylamines, imines, azides, nitriles, isocyanates, isocyanides, nitrites, nitrosos, thiols, thioethers, sulfoxides, sulfonic acids, thiocyanates, isothiocyanates, thiones, thials, phosphines, phosphonic acids, phosphates, boronic acid, boronic esters, borinic acids, hetroaromatics, and heterocycles.
  • a catalyst is a substance that increases the rate of a chemical reaction by reducing the activation energy, but which is left unchanged by the reaction.
  • the catalyst in the polymerization reactions can be selected to control the equilibrium constant between the active and dormant species. This equilibrium determines the polymerization rate.
  • Catalysts selected to have a small equilibrium constant can be used in contexts where it is desirable to inhibit or slow the polymerization reaction while catalysts selected to have a large equilibrium constant can be used in contexts where it is desirable to have a high distribution of chain lengths.
  • the catalyst is a metal photoredox catalyst.
  • photoredox catalysts see J. M. R. Narayanam, et al. Chem. Soc. Rev. 2011, 40, 102-113.
  • the photoredox catalyst is selected from a group consisting of transition metal complexes. In certain embodiments, the amount of catalyst is less than 20 mol % but more than 0.00001 mol % relative to the amount of monomer used. In one particular embodiment, the photoredox catalyst is ac-Ir(ppy) 3 . Photoredox catalysts other than ac-Ir(ppy) 3 may also be used, which include but are not limited to those shown in Figure 14A-14C. Selected photoredox catalysts can
  • Transition metals other than Ir and Ru that can be used as part of a selected photoredox catalyst complex include, but are not limited to, Cr, Co, Fe, Rh, Mn, Pt, Pd, Os, Eu, Cu, Al, Ti, Zn, Cd.
  • Photoredox catalysts are well known in the art (see, e.g. D. A. Nicewicz, et al. Science 2008, 322, 77-80). However, such catalysts have been used only for specific aspects of the polymerization process and not the whole process. Moreover, they have only been successful as photoinitiators, employing light to initiate the reactions and not as a means to have precise control over the chain growth process of radical polymerizations, reversibly mediating initiation, polymerization and deactivation steps (see, e.g. Lalevee et al, ACS MACRO LETT., 286-290 (2012).
  • photoredox catalysts can now be used in systems and methods of highly responsive photocontroUed radical polymerization.
  • a free radical polymerization method and system is provided that can be efficiently controlled (e.g., reversibly activated/deactivated) by an external stimulus (light) with all of the desired attributes described above.
  • this invention can use sub-stoichiometric levels of a photoredox catalyst, has an uncomplicated and easy process setup, and is tolerant of reactive functional groups, such as carboxylic acids, epoxides, amines, etc, because of the robust nature of these catalysts. Because these functional groups have been shown to interfere with other radical procedures, this invention is highly attractive and has widespread application in a number of fields.
  • an exemplary photoredox mechanism for the controlled radical polymerization is shown in Figure 1.
  • Photoredox catalysts (M, Figure 1) have been shown to absorb light to afford a complex in the excited state (M(n)*).
  • This excited M(n)* species reduces the alkyl halide or pseudo halide to give the desired alkyl radical, which undergoes polymerization with an alkene monomer that is chosen from typical alkene monomers that undergo traditional radical polymerization.
  • the highly oxidizing M(n+1) complex then reacts with the alkyl radical to afford the initial M(n) complex in the ground state, as well as an alkyl halide/pseudo halide capped polymer. In certain embodiments, this process is repeated with the aid of an additional photon of light
  • the oxidation of the radical to form the alkyl halide/pseudo halide chain end gives rise to a controlled and radical polymerization process.
  • An advantage of this type of system is the ability to reversibly activate or reversibly deactivate the polymerization with visible light. Specifically, when light is removed from this reaction no M(n)* will be present, therefore, the radical chain ends will be oxidized and the reaction will rest at the dormant and stable alkyl halide/pseudo halide species. Furthermore, upon re-exposure to light, M(n)* will be formed, re-activating the polymerization.
  • Various metals can be used in the design of the photoredox catalyst, with Ir and Ru being two examples.
  • the mechanism for photocontrolled radical polymerization is shown in Figure 4.
  • ac-[Ir(ppy) 3 ] a commercially available complex, has been shown to absorb visible light to afford fac- [Ir(ppy) 3 ]*.
  • This excited Ir 111 * species reduces an alkyl bromide initiator to give the desired alkyl radical, which initiates polymerization of the monomer.
  • the highly oxidizing Ir IV complex then reacts with the propagating radical to afford the initial Ir 111 complex in the ground state, as well as a dormant polymer chain with a bromo end group.
  • Example 1 ILLUSTRATIVE METHODS AND MATERIALS USEFUL IN LIGHT MEDIATED CONTROLLED RADICAL POLYMERIZATION REACTIONS
  • Radical polymerizations have become a powerful and widely utilized synthetic tool for the formation of well-defined polymers that are diverse in their structure and function.
  • the capability to regulate these processes by an external stimulus would greatly increase their applicability across a number of fields and allow for the synthesis of previously inaccessible macromolecular structures.
  • a radical polymerization that can be efficiently and reversibly activated or deactivated by light has been developed.
  • This new polymerization process is highly responsive to the external stimulus (light) and allows for both temporal and spatial control over the chain growth process.
  • a Varian Cary Eclipse Fluorescence Spectrophotometer was used for the quenching studies.
  • the Ir(ppy) 3 (complex 1) solutions were excited at 334 nm.
  • the emission of a 0.13 mM solution of complex 1 in DMF was first measured at varying concentrations of MMA (0 - 112 mM). As shown in Figures 8 and 9 no quenching of the emission of complex 1 was observed at any of the concentrations of MMA.
  • the emission of a 0.13 mM solution of complex 1 in DMF was also measured at varying concentrations of ethyl a- bromophenylacetate (0 - 136 mM). As shown in Figures 9 and 10 a concentration dependent fluorescence quenching was observed.
  • the reaction was stirred in front of a 50 W fluorescent lamp, and aliquots were removed from the reaction mixture via syringe under a positive pressure of argon at different time points.
  • the samples were analyzed by 1H NMR to give the conversion of MMA and GPC to give the number average molecular weight (M n ), weight average molecular weight (M w ) and molecular weight distribution (M w /M n ) of the polymer.
  • M n number average molecular weight
  • M w weight average molecular weight
  • M w /M n molecular weight distribution
  • reaction mixture was transferred via cannula to an erlenmeyer flask containing a cold mixture of methanol and water (10: 1, 300 mL) that was being vigorously stirred.
  • a white precipitate formed, which was filtered, taken up in a minimal amount of CH 2 CI 2 and precipitated a second time from a cold mixture of methanol and water (10: 1, 300 mL).
  • the white precipitate was then filtered and dried to give 423 mg of the desired product. This product was used as the macroinitiator in the reaction that is described in the next section.
  • the vial was then backfilled with argon and a solution of complex 1 in DMF (200 ⁇ ,, 0.01 mol %), which had been degassed in an analogous fashion as described for the reaction mixture above, was injected via syringe.
  • the reaction was stirred in front of a 50 W fluorescent lamp for 5 hours and then covered with aluminum foil for 5 minutes.
  • the reaction mixture was then added in a dropwise fashion to an erlenmeyer flask containing a mixture of cold methanol and water (10: 1, 200 mL) that was being vigorously stirred.
  • a white precipitate formed, which was filtered, taken up in a minimal amount of CH2CI2 and precipitated a second time from a cold mixture of methanol and water (10: 1, 200 mL).
  • the vial was then backfilled with argon and ethyl a-bromophenylacetate (5.24 ⁇ , 0.030 mmol) was injected via syringe.
  • the reaction was stirred in front of a 50 W fluorescent lamp for 5 hours (1H NMR of the crude reaction mixture showed ca. 50% conversion of the benzyl methacrylate).
  • the reaction mixture was then added dropwise to cold diethyl ether (250 mL) that was being vigorously stirred. An off- white precipitate formed, which was filtered, taken up in a minimal amount of CH 2 CI 2 and was precipitated a second time from cold diethyl ether (250 mL). The off- white precipitate was then filtered and dried to give 475 mg of the desired product.

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  • Graft Or Block Polymers (AREA)

Abstract

Les procédés de polymérisation radicalaire vivante constituent désormais l'une des stratégies de synthèse les plus efficaces pour la préparation d'une grande variété de matériaux fonctionnels. La possibilité de réguler ces processus au moyen d'un stimulus extérieur augmente fortement leur utilité, permet, en outre, à ces procédés de polymérisation radicalaire vivante de fournir de nouvelles structures macromoléculaires et est à l'origine d'un nombre plus grand encore d'applications possibles. La présente demande de brevet concerne, donc, une procédure de polymérisation radicalaire vivante permettant de réguler la croissance de la chaîne sous l'effet de la lumière visible. Des modes de réalisation de l'invention montrent une activation et une désactivation sans précédent des réactions de polymérisation par la lumière visible, ainsi qu'une remarquable régulation de la masse moléculaire et de la distribution des masses moléculaires des polymères fabriqués par ce procédé.
PCT/US2013/033933 2012-03-26 2013-03-26 Régulation de la polymérisation radicalaire vivante par la lumière WO2013148722A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106164109A (zh) * 2014-04-07 2016-11-23 陶氏环球技术有限责任公司 通过光的丙烯酸酯的可控自由基聚合的调节
WO2018140977A1 (fr) * 2017-01-30 2018-08-02 Massachusetts Institute Of Technology Réactions activées par des gels thermosensibles et photosensibles
CN112430288A (zh) * 2020-10-30 2021-03-02 河南聚元新材料科技有限公司 一种可见光引发常压制备膨胀微球的方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6455064B1 (en) * 1998-04-30 2002-09-24 Closure Medical Corporation Method of applying an adhesive composition over a bioactive polymerization initiator or accelerator
US20090188622A1 (en) * 2008-01-30 2009-07-30 Ada Foundation Hydrolytically Stable, Hydrophilic Adhesion-Promoting Monomers and Polymers Made Therefrom
US20110046324A1 (en) * 2008-03-07 2011-02-24 Krzysztof Matyjaszewski Improved controlled radical polymerization processes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6455064B1 (en) * 1998-04-30 2002-09-24 Closure Medical Corporation Method of applying an adhesive composition over a bioactive polymerization initiator or accelerator
US20090188622A1 (en) * 2008-01-30 2009-07-30 Ada Foundation Hydrolytically Stable, Hydrophilic Adhesion-Promoting Monomers and Polymers Made Therefrom
US20110046324A1 (en) * 2008-03-07 2011-02-24 Krzysztof Matyjaszewski Improved controlled radical polymerization processes

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
LEE ET AL.: "Spatio-Resolved, Macromolecular Architectural Surface: Highly Branched Graft Polymer via Photochemically Driven Quasiliving Polymerization Technique.", AMERICAN CHEMICAL SOCIETY, 23 September 1999 (1999-09-23), Retrieved from the Internet <URL:http://pubs.acs.org/doi/abs/10.1021/ma990566b> [retrieved on 20130523] *
ZHANG ET AL.: "Free Radical Polymerization Initiated and Controlled by Visible Light Photocatalysis at Ambient Temperature.", ACS PUBLICATIONS, 6 September 2011 (2011-09-06), Retrieved from the Internet <URL:http://www.researchgate.net/publication/229458153_Free_radical_polymerization_initiated_and_controlled_by_visible_light_photocatalysis_at_ambient_condition/file/79e41510b207229368.pdf> [retrieved on 20130523] *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106164109A (zh) * 2014-04-07 2016-11-23 陶氏环球技术有限责任公司 通过光的丙烯酸酯的可控自由基聚合的调节
JP2017515931A (ja) * 2014-04-07 2017-06-15 ダウ グローバル テクノロジーズ エルエルシー 光によるアクリレートの制御ラジカル重合の調節
WO2018140977A1 (fr) * 2017-01-30 2018-08-02 Massachusetts Institute Of Technology Réactions activées par des gels thermosensibles et photosensibles
US11041026B2 (en) 2017-01-30 2021-06-22 Massachusetts Institute Of Technology Reactions enabled by thermoresponsive and photoresponsive gels
CN112430288A (zh) * 2020-10-30 2021-03-02 河南聚元新材料科技有限公司 一种可见光引发常压制备膨胀微球的方法

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