Classifications

• • 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
  • C08F2/50—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light with sensitising agents
• • 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
  • C08F26/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen
  • C08F26/02—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen by a single or double bond to nitrogen
• • 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
  • C08F4/00—Polymerisation catalysts

Definitions

• the present invention provides photoiniferters for radical polymerization processes and telechelic polymers made thereby.
• radicals are generated reversibly, and irreversible chain transfer and chain termination are absent.
• ATRP atom transfer radical polymerization
• RAFT reversible addition-fragmentation chain transfer
• NMP nitroxide-mediated polymerization
• iniferters each method having advantages and disadvantages.
• iniferter refers to a chemical compound that has a combined function of being a free radical initiator, transfer agent, and terminator, the term “iniferter” being a word formed by the underlined portions of the terms identifying these functions.
• the photo portion of the term indicates that the polymerization is photolytically induced.
• This term and its use in the production of block copolymers is well known, particularly because of the work of Takayuki Otsu of the Department of Applied Chemistry, Osaka City University, Osaka, Japan.
• R 1 and R 2 are each independently selected from H, an alkyl group, a nitrile group, a cycloalkyl group, a heterocyclic group, an arenyl group and an aryl group, or R and R taken together with the carbon to which they are attached form a carbocyclic ring;
• R 3 and R 4 are each independently selected from an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, or R 3 and R 4 taken together with the carbon to which they are attached form a carbocyclic ring;
• R 5 and R 6 are each independently selected from an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, or R 5 and R taken together with the nitrogen to which they are attached form a heterocyclic ring, R and R are optionally substituted with phosphate, phosphonate, sulfonate, ester, halogen, nitrile, amide, and
• Q is a linking group selected from a covalent bond, an arenyl group, an aryl group (-CH 2 - ) 0 , -CO-O-(CH 2 ) 0 -, -CO-O-(CH 2 CH 2 O)o-, -CO-NR 8 -(CH 2 ) 0 -,-CO-S-(CH 2 ) 0 -, where o is 1 to 12, and R 8 is H, an alkyl group, a cycloalkyl group, an arenyl group or an aryl group; and n is 0 or 1.
• the present invention also provides photoiniferters that comprise the ring-opened reaction product of the photoiniferters of Formula I and a reactive compound, such as an aliphatic compound, having one or more nucleophilic groups.
• a reactive compound such as an aliphatic compound, having one or more nucleophilic groups.
• R 1 and R 2 are each independently selected from H, a nitrile group, an alkyl group, a cycloalkyl group, an arenyl group, a heterocyclic group and an aryl group or R 1 and R 2 taken together with the carbon to which they are attached form a carbocyclic ring;
• R 3 and R 4 are each independently selected from an alkyl group, a cycloalkyl group, an aryl, an arenyl group, or R 3 and R 4 taken together with the carbon to which they are attached form a carbocyclic ring;
• R 5 and R 6 are each independently selected from an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, or R 5 and R taken together with the nitrogen to which they are attached form a heterocyclic ring, R 5 and R 6 are optionally substituted with phosphate, phosphonate, sulfonate, ester, halogen, nitrile, amide, and hydroxy groups;
• R 5 and R 6 may optionally be substituted with one or more caternary heteroatoms, such as oxygen, nitrogen or sulfur; n is 0 or 1 ;
• Z is O, S or NR 8 , wherein R 8 is H, an alkyl group, a cycloalkyl group, an arenyl group, a heterocyclic group or an aryl group; R 7 is an organic or inorganic moiety and has a valency of m, R 7 is the residue of a mono- or polyfunctional compound of the formula R 7 (ZH) m ;
• Q is a linking group selected from a covalent bond, an aryl group, an arenyl group,
• the photoiniferters of the present invention provide (co)polymers having a predictable molecular weight and a narrow molecular weight distribution.
• the photoiniferters provide novel multireactive addition polymers having first and second terminal reactive groups that may be used for further functionalization.
• the present invention further provides a controlled radical polymerization process useful in the preparation of terminal-functionalized (telechelic) (co)polymers, block copolymers, star (co)polymers, graft copolymers, and comb copolymers. The process provides these (co)polymers with controlled topologies and compositions.
• control over molecular weight and functionality obtained in this invention allows one to synthesize numerous materials with many novel topologies for applications in coatings, surface modifications, elastomers, sealants, lubricants, pigments, personal care compositions, composites, inks, adhesives, water treatment materials, hydrogels, imaging materials, telechelic materials and the like.
• the invention provides a method for polymerization of one or more olefinically unsaturated monomers comprising addition polymerizing one or more olefinically unsaturated monomers using the photoiniferter comprising the azlactone photoiniferters, or the ring-opened azlactone photoiniferter. It is to be understood that the recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
• alkyl refers to straight or branched, cyclic or acyclic hydrocarbon radicals, such as methyl, ethyl, propyl, butyl, octyl, isopropyl, tert-butyl, sec-pentyl, cyclohexyl, and the like.
• Alkyl groups include, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, or most preferably 1 to 6 carbon atoms.
• aryl means the monovalent residue remaining after removal of one hydrogen atom from an aromatic compound which can consist of one ring , two or three fused or catenated rings having 6 to 14 carbon atoms.
• arenyl means the monovalent residue remaining after removal of a hydrogen atom from the alkyl portion of a hydrocarbon containing both alkyl and aryl groups having 6 to 26 atoms, optionally substituted with one or more catenary heteroatoms.
• azlactone means 2-oxazolin-5-one groups and 2-oxazolin-6-one groups of Formula I, where n is 0 and 1, respectively.
• heterocyclic group or “heterocycle” means the monovalent residue remaining after removal of one hydrogen atom from an cycloaliphatic or aromatic compound having one, two or three fused rings having 5 to 12 ring atoms and 1 to 3 heteroatoms selected from S, N, and nonperoxidic O.
• Useful heterocycles include azlactone, pyrrole, furan, thiophene, imidazole, pyrazole, thiazole, oxazole, pyridine, piperazine, piperidine, and hydrogenated and partially hydrogenated derivatives thereof
• multifunctional means the presence of more than one of the same functional reactive group;
• multireactive means the presence of two or more of two different functional reactive groups
• polyfunctional is inclusive of multireactive and multifunctional.
• acid catalyst or “acid catalyzed” means catalysis by a Br ⁇ nsted- or
• molecular weight means number average molecular weight (M n ), unless otherwise specified.
• (co)polymer refers to homo- and copolymers.
• (meth)acrylate refers to both methacrylate and acrylate.
• the present invention provides novel photoiniferters of Formula I and the corresponding ring-opened photoiniferters of Formula II for controlled radical polymerization processes.
• R 1 and R 2 are each independently selected from H, an alkyl group of 1 to 18 carbon atoms, a nitrile, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 14 ring atoms, an arenyl group having 6 to 26 carbon atoms, a heterocyclic group having one , two or three fused rings having 5 to 12 ring atoms and 1 to 3 heteroatoms selected from S, N, and nonperoxidic O; or R 1 and R 2 taken together with the carbon to which they are attached form a carbocyclic ring containing 4 to 12 ring atoms.
• R 3 and R 4 are each independently selected from an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 14 ring atoms, an arenyl group having 6 to 26 carbon atoms and 0 to 3 S, N, and nonperoxidic O heteroatoms, or R 3 and R 4 taken together with the carbon to which they are attached form a carbocyclic ring containing 4 to 12 ring atoms;
• R 5 and R 6 are each independently selected from an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, or R and R taken together with the nitrogen to which they are attached form a heterocyclic ring, R and R are optionally substituted with phosphate, phosphonate, sulfonate, ester, halogen, nitrile, amide, and hydroxy groups;
• R 5 and R 6 may optionally be substituted with one or more catern
• olefinically unsaturated monomers examples include (meth)acrylates such as ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isooctyl (meth)acrylate and other alkyl (meth)acrylates; also functionalized (meth)acrylates including glycidyl (meth)acrylate, poly(ethyleneoxide) (meth)acrylate, trimethoxysilyl propyl (meth)acrylate, allyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, mono- and dialkyl aminoalkyl (meth)acrylates; mercaptoalkyl (meth)acrylates, fluoroalkyl (meth)acrylates; (meth)acrylic acid, fumaric acid (and esters), itaconic acid (and esters), maleic anhydride; styrenethacrylate,
• Monomers having pendent, nucleophilic functional groups such as hydroxy-, amino- or thiol- functional groups are particularly useful for providing so-called AB corrosion polymers.
• Such pendent nucleophilic functional groups may react with the azlactone terminal group to provide novel architectures.
• Such pendent nucleophilic functional groups may be protected during the polymerization, and deprotected post-polymerization for providing novel polymer architecture.
• Photoiniferters of Formula I may be prepared using the generalized sequence as shown:
• an amino acid is first acylated, generally by dissolving the amino acid in aqueous base, followed by treatment with the acyl halide compound under interfacial reaction conditions.
• Cyclization may be effected by treatment with acetic anhydride and pyridine, by treatment with carbodiimides, or preferably by treatment with ethyl chloroformate and a trialkylamine, which proceeds through a mixed carboxylic-carbonic anhydride.
• the dithiocarbamate moiety is introduced by displacement of the X group.
• DiTC is a dithiocarbamate group of the formula R 5 R 6 N-C(S)-S-,
• R 1 is selected from H, an alkyl group of 1 to 18 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 14 ring atoms, an arenyl group having 6 to 26 carbon atoms, a heterocyclic group having one, two or three fused rings having 5 to 12 ring atoms and 1 to 3 heteroatoms selected from S, N, and nonperoxidic O;
• R 3 and R 4 are each independently selected from an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 14 ring atoms, an arenyl group having 6 to 26 carbon atoms and 0 to 3 S, N, and nonperoxidic O heteroatoms, or R 3 and R 4 taken together with the carbon to which they are attached form a carbocyclic ring containing 4 to 12 ring atoms;
• R 5 and R 6 are each independently selected from an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, a heterocyclic group, or R 5 and R 6 taken together with the nitrogen to which they are attached form a heterocyclic ring, R 5 and R 6 are optionally substituted with phosphate, phosphonate, sulfonate, ester, halogen, nitrile, amide, and hydroxy groups; R and R may optionally be substituted with one or more caternary heteroatoms, such as oxygen, nitrogen or sulfur;
• R 9 is a divalent alkylene group of 1 to 18 carbon atoms, a cycloalkylene group having 3 to 14 carbon atoms, an aryl group having 6 to 14 ring atoms, a heterocyclic group, or an arenyl group having 6 to 26 carbon atoms,
• Q is a linking group selected from a covalent bond, (-CH 2 -) 0 , -CO-O-(CH 2 ) 0 ⁇ , -CO-O- (CH 2 CH 2 O) 0 -, -CO-NR 8 -(CH 2 )o-,-CO-S-(CH 2 ) 0 -, where o is 1 to 12, and R 8 is H, an alkyl group, a cycloalkyl group, an arenyl group, a heterocyclic group or an aryl group; and o is 0 or 1.
• Useful azlactone photoiniferters include the following compounds:
• Ring-opened azlactone compounds of Formula JJ may be made by nucleophilic addition of a compound of the formula R 7 (ZH) m to the azlactone carbonyl of Formula I as shown below.
• R 7 is an inorganic or organic group having one or a plurality of nucleophilic -ZH groups, which are capable of reacting with the azlactone moiety of Formula I.
• R 7 (ZH) m may be water.
• such ring opened compounds may be prepared by nucleophilic addition of a compound of the formula R 7 (ZH) m to the halogen-containing ("X") azlactone, followed by displacement of the X group with the dithiocarbamate, as shown in Scheme III.
• R 7 may be a polymeric or non-polymeric organic group that has a valence of m and is the residue of a nucleophilic group-substituted compound, R 7 (ZH) m , in
• Z is -O-, -S-, or -NR
• R can be a H, an alkyl, a cycloalkyl or aryl, a heterocyclic group, an arenyl and m is at least one, preferably at least 2.
• R 7 moiety R has a molecular weight up to 20,000, preferably selected from mono- and polyvalent hydrocarbyl (i.e., aliphatic and aryl compounds having 1 to 30 carbon atoms and optionally zero to four heteroatoms of oxygen, nitrogen or sulfur), polyolefin, polyoxyalkylene, polyester, polyolefin, poly(meth)acrylate, or polysiloxane backbones. If inorganic, R 7 may comprise silica, alumina or glass having one or a plurality of -ZH groups on the surface.
• mono- and polyvalent hydrocarbyl i.e., aliphatic and aryl compounds having 1 to 30 carbon atoms and optionally zero to four heteroatoms of oxygen, nitrogen or sulfur
• R 7 may comprise silica, alumina or glass having one or a plurality of -ZH groups on the surface.
• R 7 comprises a non-polymeric aliphatic, cycloaliphatic, aromatic or alkyl-substituted aromatic moiety having from 1 to 30 carbon atoms.
• R 7 comprises a polyoxyalkylene, polyester, polyolefin, poly(meth)acrylate, or polysiloxane polymer having pendent or terminal reactive -ZH groups.
• Useful polymers include, for example, hydroxyl, thiol or amino terminated polyethylenes or polypropylenes, hydroxyl, thiol or amino terminated poly(alkylene oxides) and poly(meth)acylates having pendant reactive functional groups, such as hydroxyethyl acrylate polymers and copolymers.
• a catalyst may be added to effect the condensation reaction. Normally, primary amine groups do not require catalysts to achieve an effective rate. Acid catalysts such as trifluoroacetic, ethanesulfonic, and toluenesulfonic acids are effective with hydroxyl groups and secondary amines.
• m is at least one, but preferably m is at least two.
• the multiple -ZH groups of the polyfunctional compound may be the same or different. Multifunctional compounds may be reacted with the azlactone compound of
• Formula I to produce polyfunctional photoiniferters of Formula II, where m is at least two.
• Such polyfunctional photoiniferters allow the preparation of graft, branched, and star (co)polymers and other useful topologies.
• Useful alcohols of the formula R 7 (ZH) m include aliphatic and aromatic monoalcohols and polyols.
• Useful monoalcohols include methanol, ethanol, octanol, decanol, and phenol.
• the polyols useful in the present invention include aliphatic or aromatic polyols having at least two hydroxyl groups.
• polystyrene resin examples include ethylene glycol, propylene glycol, butanediol, 1,3-pentane diol, 2,2-oxydiethanol, hexanediol, poly(pentyleneadipate glycol), poly(tetramethylene ether glycol), poly(ethylene glycol), poly(caprolactone diol), poly(l,2-butylene oxide glycol), trimethylol ethane, trimethylol propane, trimethyol aminomethane, ethylene glycol, 2- butene-l,4-diol, pentaerythritol, dipentaerythritol, and tripentaerythritol.
• polyol also includes derivatives of the above-described polyols such as the reaction product of the polyol with di- or poly-isocyanate, or di- or poly-carboxylic acid, the molar ratio of polyol to -NCO, or -COOH being 1 to 1.
• Useful amines of the formula R 7 (ZH) ra include aliphatic and aromatic monoamines and polyamines. Any primary or secondary amine may be employed, although primary amines are preferred to secondary amines.
• Useful monoamines include, for example, methyl-, ethyl-, propyl-, hexyl-, octyl, dodecyl-, dimethyl-, methyl ethyl-, and aniline.
• the term "di-, or polyamine,” refers to organic compounds containing at least two non-tertiary amine groups. Aliphatic, aromatic, cycloaliphatic, and oligomeric di- and polyamines all are considered useful in the practice of the invention.
• di- or polyamines Representative of the classes of useful di- or polyamines are 4,4'-methylene dianiline, 3,9-bis-(3-aminopropyl)-2,4,8,10- tetraoxaspiro[5,5]undecane, and polyoxyethylenediamine. Many di- and polyamines, such as those just named, are available commercially, for example, those available from
• the most preferred di- or polyamines include aliphatic diamines or aliphatic di- or polyamines and more specifically compounds with two primary amino groups, such as ethylene diamine, hexamethylene diamine, dodecanediamine, and the like.
• Useful thiols of the formula R 7 (ZH) m include aliphatic and aromatic monothiols and polythiols
• Useful alkyl thiols include methyl, ethyl and butyl thiol, as well as 2- mercaptoethanol, 3-mercapto-l,2-propanediol, 4-mercaptobutanol, mercaptoundecanol, 2- mercaptoethylamine, 2,3-dimercaptopropanol, 3-mercaptopropyltrimethoxysilane, 2- chloroethanethiol, 2-amino-3-mercaptopropionic acid, dodecyl mercaptan, thiophenol, 2- mercaptoethyl ether, and pentaerythritol tetrathioglycolate.
• Useful soluble, high molecular weight thiols include polyethylene glycol di(2-mercaptoacetate), LP-3 m resins supplied by Morton Thiokol Inc. (Trenton, N.J.), and Permapol P3 tm resins supplied by Products
• the invention provides multifunctional photoiniferters of Formula II, whereby an azlactone photoiniferter of Formula I is ring-opened by a multireactive or multifunctional compound of the formula R (ZH) m , where m is at least 2.
• Such multifunctional photoiniferters may be used to produce branched, star and graft (co)polymers and other topologies. It will also be apparent that such (co)polymers may also be prepared by first polymerizing a monomer using the photoiniferter of Formula I, to produce polymers having an azlactone group at one terminal end, and then subsequently reacting the polymers with a polyfunctional compound of the formula R 7 (ZH) m , where m is at least 2.
• the multifunctional photoiniferters may comprise a solid support having a plurality of photoiniferter moieties on the surface thereof.
• Such photoiniferter-functionalized supports have the general structure (corresponding to Formula II):
• the solid support material includes functional groups to which photoiniferter molecules of Formula I can be covalently attached for building large or small organic compounds.
• Useful functional groups include hydroxyl, amino and thiol functional groups corresponding to -ZH.
• the support material can be organic or inorganic. It can be in the form of solids, gels, glasses, etc.
• It can be in the form of a plurality of particles (e.g., beads, pellets, or microspheres), fibers, a membrane (e.g., sheet or film), a disc, a ring, a tube, or a rod, for example.
• a membrane e.g., sheet or film
• it is in the form of a plurality of particles or a membrane. It can be swellable or non-swellable and porous or nonporous.
• the support material can be a polymeric material that can be used in conventional solid phase synthesis. It is chosen such that it is generally insoluble in the solvents or other components used in synthetic reactions that occur during the course of solid phase synthesis. Examples of useable pre-existing support materials are described in G.B. Fields et al., Int. J. Peptide Protein Res., 35, 161 (1990) and G.B. Fields et al., in Synthetic Peptides: A User's Guide, G.A. Grant, Ed., pages 77-183, W.H. Freeman and Co., New York, NY (1992).
• the support material is in the form of an organic polymeric material, such as polystyrenes, polyalkylenes, nylons, polysulfones, polyacrylates, polycarbonates, polyesters, polyimides, polyurethanes, etc. and having hydroxyl, amino or thiol substituents on the surface.
• an organic polymeric material such as polystyrenes, polyalkylenes, nylons, polysulfones, polyacrylates, polycarbonates, polyesters, polyimides, polyurethanes, etc. and having hydroxyl, amino or thiol substituents on the surface.
• a preferred support material is polystyrene.
• the amounts and relative proportions of photoiniferter and monomer are those effective to conduct radical polymerization. Accordingly, the amount of photoiniferter can be selected such that the photoiniferter concentration is from 10 "5 M to 1M, preferably 10 "4 to 10 "2 M. Alternatively, the photoiniferter can be present in a molar ratio of from 10 "5 : 1 to 10 "1 : 1, preferably from 10 " 5 :1 to 2xl0 "3 :1, relative to monomer.
• the present polymerization may be conducted in bulk, or in a solvent.
• Solvents preferably organic, can be used to assist in the dissolution of the photoiniferter in the polymerizable monomers, and as a processing aid.
• such solvents are not reactive with the azlactone group.
• Suitable solvents include ethers such as diethyl ether, ethyl propyl ether, dipropyl ether, methyl t-butyl ether, di-t-butyl ether, glyme (dimethoxyethane), diglyme, diethylene glycol dimethyl ether; cyclic ethers such as tetrahydrofuran and dioxane; alkanes; cycloalkanes; aromatic hydrocarbon solvents such as benzene, toluene, o-xylene, m-xylene, p-xylene; halogenated hydrocarbon solvents; acetonitrile; lactones such as butyrolactone, and valerolactones; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; sulfones such as tetramethylene s
• the photoiniferter is caused to dissociate to form free radicals by exposure to an appropriate radiant energy source.
• the particular energy source and its intensity are selected to result in dissociation of the photoiniferter to free radicals.
• an ultraviolet light source is utilized.
• a visible light source is utilized.
• a visible light source is preferably used since it is more convenient and is considered less hazardous.
• the intensity and rate of radiation is chosen so that it will advance the polymerization at a reasonable rate without deleteriously affecting the polymer segment being produced.
• a light source having a wavelength on the order of 200 to 800 nm spaced approximately 10 cm from the reactants to provide an exposure of 1.25 milliwatts per square centimeter has been found to produce suitable results. If the energy source is ultraviolet radiation, a suitable ultraviolet light transparent vessel is utilized.
• UV light sources can be of two types: 1) relatively low light intensity sources such as blacklights which provide generally 10 mW/cm ⁇ or less (as measured in accordance with procedures approved by the United States National Institute of Standards and Technology as, for example, with a UVIMATM UM 365 L-S radiometer manufactured by Electronic Instrumentation & Technology, Inc., in Sterling, Va.) over a wavelength range of 280 to 400 nanometers and 2) relatively high light intensity sources such as medium pressure mercury lamps which provide intensities generally greater than 10 mW/cm ⁇ , preferably between 15 and 450 mW/cm ⁇ .
• relatively low light intensity sources such as blacklights which provide generally 10 mW/cm ⁇ or less (as measured in accordance with procedures approved by the United States National Institute of Standards and Technology as, for example, with a UVIMATM UM 365 L-S radiometer manufactured by Electronic Instrumentation & Technology, Inc., in Sterling, Va.) over a wavelength range of 280 to 400 nanometers
• relatively high light intensity sources such
• actinic radiation is used to fully or partially crosslink the polymer composition
• high intensities and short exposure times are preferred.
• an intensity of 600 mW/cmr and an exposure time of about 1 second may be used successfully.
• Intensities can range from about 0.1 to about 150 mW/cm ⁇ , preferably from about 0.5 to about 100 mW/cm ⁇ , and more preferably from about 0.5 to about 50 mW/cm.2 .
• the photoiniferter Upon exposure to the energy source, the photoiniferter dissociates to form free radicals that promote free radical polymerization.
• the energy source is discontinued to permit the free radically polymerized segments to recombine with the terminator portion of the photoiniferter to form polymer segments.
• a second monomer charge may then be introduced if desired, which is free radically polymerizable to the block A', and the new mixture is exposed to the energy source to cause dissociation of the terminator radical and free radical polymerization of the second monomer charge onto the first polymer segment, that now being the photoiniferter of the second free radical polymerization.
• the energy source Upon completion of polymerization of the second monomer charge, the energy source is terminated and the terminator portion of the photoiniferter recombines with the polymer block to provide a block copoly'mer
• Polymerizing may be conducted at a temperature of from -78 to 200°C, preferably from 0 to 160°C and most preferably from 0 to 30°C.
• the reaction should be conducted for a length of time sufficient to convert at least 1 % of the monomer to polymer.
• the reaction time will be from several minutes to 5 days, preferably from 30 minutes to 3 days, and most preferably from 1 to 24 hours.
• Polymerizing may be conducted at a pressure of from 0.1 to 100 atmospheres, preferably from 1 to 50 atmospheres and most preferably at ambient pressure (although the pressure may not be measurable directly if conducted in a sealed vessel).
• An inert gas such as nitrogen or argon may be used.
• Useful accelerants include metal compounds represented by the general formula MyL z wherein M is a cation having a valency of z of a metal which is selected from the group consisting of tin, zinc, cobalt, titanium, palladium, and lead; y is an integer of at least 1 ; L is an anion selected from the group consisting of Ci-C 20 alkyl, -aryl, -OR, -O-C(O)-R, NO3--, SO4 2 -, and PO4 3 - ; R is selected from the group consisting C ⁇ _20 alkyl and aryl; and z is an integer of at least 1.
• the metal compound is selected from the group consisting of stannous 2-ethylhexanoate, zinc 2-ethylhexanoate and mixtures thereof.
• stannous 2-ethylhexanoate zinc 2-ethylhexanoate and mixtures thereof.
• the polymerization reaction may benefit from the use of polymerization modifiers such as thiuram compounds, such as those disclosed in Otsu, T. et al., Journal of Polymer Science: Part A: Polymer Chemistry, 1994, Vol. 32, 2911-2918, and in Otsu, T. et al., European Polymer Journal, 1995, Vol. 31, 67-78.
• polymerization modifiers such as thiuram compounds, such as those disclosed in Otsu, T. et al., Journal of Polymer Science: Part A: Polymer Chemistry, 1994, Vol. 32, 2911-2918, and in Otsu, T. et al., European Polymer Journal, 1995, Vol. 31, 67-78.
• thiuram compounds such as those disclosed in Otsu, T. et al., Journal of Polymer Science: Part A: Polymer Chemistry, 1994, Vol. 32, 2911-2918, and in Otsu, T. et al., European Polymer Journal
• the (co)polymers obtained by the method of the invention may be described as telechelic (co)polymers comprising polymerized units of one or more free radically (co)polymerizable monomers (as previously described), a first azlactone terminal group derived from the photoiniferter of Formula I and a second terminal group selected from the group derived from dithiocarbamate.
• the first terminal group "Az” will comprise the ring-opened residue of the azlactone group of the Formula III:
• Such (co)polymers have the general formula Az-(M 1 ) x (M 2 ) x (M 3 ) x ...(M ⁇ ) x -DiTC flash wherein "DiTC" is a dithiocarbamate group of the formula R 5 R 6 N-C(S)-S-, wherein R 5 and R 6 as defined in Formulas I and II; M to M are each polymerized monomer units derived from a radically
• the polymer product retains the dithiocarbamate functional group "DiTC" at one terminal end of the polymer necessary to initiate a further polymerization (or functionalization).
• the polymer product further comprises either the azlactone moiety or the ring-opened azlactone moiety of the photoiniferter at the other terminal end, which may be further reacted or functionalized as desired. Because the two terminal moieties have different functionality and reactivity, each terminus may be independently functionalized.
• the terminal dithiocarbamate group may be functionalized independently from the terminal "Az" group.
• functionalization of the azlactone followed by mild hydrolysis of the dithiocarbamate groups yields thiols, which readily oxidizes to form a dimeric polymer linked by a disulfide group. Reduction of the disulfide linkage to yield a thiol group, which then may be further functionalized.
• hydroxy-, amino- and thio-compounds add preferentially to the azlactone terminal group rather than the thiocarbamate terminal group, allowing independent functionalization.
• the present invention encompasses a novel process for preparing random, block, multi-block, star, gradient, random hyperbranched and dendritic copolymers, as well as graft or "comb" copolymers. Each of these different types of copolymers will be described hereunder.
• photoiniferter polymerization is a "living" or “controlled” polymerization, it can be initiated and terminated as desired.
• a second monomer can then be added to form a second block on the growing polymer chain in a second polymerizing step. Additional polymerizations with the same or different monomer(s) can be performed to prepare multi-block copolymers. Accelerants or thiurams may be added to control the polymerization of subsequent blocks as desired.
• blocks can be prepared in essentially any order.
• a multi-block copolymer in which a polyacrylonitrile or a poly(meth)acrylate block is prepared first, then a styrene or butadiene block is attached thereto, etc.
• a linking group is not necessary to join the different blocks of the present block copolymer.
• the product polymer having a terminal dithiocarbamate group acts as the new photoiniferter for the further polymerization of the additional monomer.
• linking groups may be used to join two polymer blocks.
• a polymer prepared in accord with the present invention, and having an azlactone group at one terminus may be reacted with a second polymer block having a nucleophilic terminal group.
• Statistical copolymers may be produced using the photoiniferters of the present invention. Such copolymers may use 2 or more monomers in a range of about 0-100% by weight of each of the monomers used.
• the product copolymer will be a function of the molar amounts of the monomers used and the relative reactivity of the monomers.
• the present invention also provides graft or "comb" copolymers. Here, a first
• (co)polymer having pendent nucleophilic functional groups such as hydroxy-, amino- or thio- groups, etc.
• An example of useful (co)polymers include hydroxyethyl acrylate (co)polymers.
• the reactive functional groups of the first (co)polymer is reacted with the azlactone photoiniferters of Formula I to provide a (co)polymer having pendent, ring-opened photoiniferter moieties, the reaction product having the structure of
• R 7 is the residue of the first (co)polymer.
• This product (co)polymer may then be used as an photoiniferter to polymerize the previously-described monomers to produce a comb (co)polymer.
• the first (co)polymer may be reacted with a telechelic (co)polymer of the invention, whereby the reactive "Az" terminal group reacts with the pendent reactive group of the first (co)polymer.
• Gradient or tapered copolymers can be produced using photoiniferter polymerization by controlling the proportion of two or more monomers being added. For example, one can prepare a first block or an oligomer of a first monomer, then a mixture of the first monomer and a second distinct monomer can be added in proportions of from, for example, 1 : 1 to 9: 1 of first monomer to second monomer. After conversion of all monomer(s) is complete, sequential additions of first monomer-second monomers mixtures can provide subsequent "blocks" in which the proportions of first monomer to second monomer vary.
• the invention provides copolymers obtained from two or more radically (co)polymerizable monomers wherein the copolymer has a composition that varies along the length of the polymer chain from azlactone terminus to opposite terminus based on the relative reactivity ratios of the monomers and instantaneous concentrations of the monomers during polymerization.
• Solvents were purchased from EM Science located in Gibbstown, N.J.
• AzDQamine benzene solution This solution was divided into five equal 10.0 g portions, which were placed in screw-cap vials. Each vial was fitted with a screw cap that had an integral valve and rubber septum. The solutions were degassed by three successive freeze- pump-thaw cycles.
• Example 7 Synthesis of Az-poly(St-co-HEMA)-DC via the Controlled Polymerization of a Styrene/2- hydroxy ethyl methacrylate Mixture With AzDC.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Polymerisation Methods In General (AREA)
• Graft Or Block Polymers (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=32326199

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (20)

Citations (1)

Family Cites Families (15)

• 2003
  • 2003-03-21 US US10/393,780 patent/US6747104B1/en not_active Expired - Lifetime
• 2004
  • 2004-02-13 DE DE602004025210T patent/DE602004025210D1/de not_active Expired - Lifetime
  • 2004-02-13 WO PCT/US2004/004255 patent/WO2004094484A1/en not_active Ceased
  • 2004-02-13 AT AT04711160T patent/ATE455800T1/de not_active IP Right Cessation
  • 2004-02-13 JP JP2006508727A patent/JP2006520844A/ja active Pending
  • 2004-02-13 EP EP04711160A patent/EP1606321B1/en not_active Expired - Lifetime
  • 2004-04-12 US US10/822,479 patent/US6818716B2/en not_active Expired - Lifetime

Patent Citations (1)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events