atom transfer radical polymerization from mechanisms to applications 2012 israel journal of...

8/11/2019 Atom Transfer Radical Polymerization From Mechanisms to Applications 2012 Israel Journal of Chemistry

1/15

DOI: 10.1002/ijch.201100101

Atom Transfer Radical Polymerization: From Mechanismsto Applications

Krzysztof Matyjaszewski*[a]

Introduction

Polymers are used every day by all of us and annual poly-mer production exceeds 200 million tons (i.e. 2 kilogramsper capita every month!). Essentially all modern technol-ogies rely on polymers, from transportation (automotiveand aircraft), microelectronics (all computers and cellphones are enabled by polymeric photoresists and LCDor OLED displays also require polymers), textile fibers,

food packaging, paints, health and beauty products, todrugs for targeted delivery and other biomedical materi-als. Recent technological progress in functional materialswas enabled by advances in polymer science, processing,characterization and especially in synthesis.

Synthesis of uniform macromolecules with preciselycontrolled size, novel topology, composition and function-ality is a prerequisite for the development of new ad-vanced materials targeting specific applications.[1] Precisesynthesis requires living polymerization techniques, whereall chains are instantaneously initiated and grow concur-rently without significant occurrence of chain breaking re-

actions, such as termination and transfer.

[2]

Typically, suchliving polymerizations are accomplished by anionic proce-dures in very stringently purified systems (with


2/15

order to minimize the proportion of terminated chains.This was extended to RP using conditions that createequilibria between growing radicals and dormant spe-cies.[4,5] The dormant species cannot terminate but can beintermittently activated to form radicals that, after addi-tion of a few monomer units, are converted back to the

dormant state. The controlled radical polymerization(CRP) methods, developed during the past 1015 years,allow the preparation of a multitude of previously unat-tainable well-defined polymeric materials.[6] Atom trans-fer radical polymerization (ATRP) is the most widelyused CRP method.[7] This minireview focuses on themechanistic understanding of ATRP, aided by computa-tional studies, as well as synthesis of well-defined poly-mers and their targeted applications.

Fundamentals of ATRP

In an ATRP, alkyl (pseudo)halide initiators/dormant mac-romolecular species (RX/PnX) react with activators, tran-sition-metal complexes in their low-oxidation state Mtm/L, (Mtm represents the transition-metal species in oxida-tion state m and L is a ligand; the charges of ionic speciesare omitted for clarity), to reversibly form propagatingradicals (PnC), and deactivators, the transition-metal com-plexes in the higher-oxidation state coordinated with(pseudo)halide ligands X-Mtm+1/L. (Scheme 1).

ATRP is a catalytic process and can be mediated bymany redox-active transition-metal complexes (CuI/L andX-CuII/L are the most frequently used transition metals,but other metals studied include Ru, Fe, Mo, Os, etc.). [8]

The rate of ATRP depends on the rate constant ofpropagation and on the concentrations of monomer and

growing radicals. The latter is defined by the ATRP equi-librium constant, the concentration of dormant speciesand the ratio of the concentrations of activator and deac-tivator, as illustrated in Equation (1).

Rp kpKATRPPnXCu

I=LM

X CuII=L

1

The nature of the ligand, L, and monomer/dormantspecies as well as reaction conditions, solvent, tempera-ture and pressure dramatically affects the values of bothrate constants, kact

[9] and kdeact,[10] and therefore their ratio,

KATRP. QuantifyingKATRP, therefore, provides an appropri-

ate measure of the catalysts activity in a polymerizationreaction.[10b,11] It should be noted that catalyst complexesare formed dynamically and are characterized by certainstability constants. Thus, the concentration of catalyticspecies and their speciation depends on the stability con-stants, hence reaction medium, and concentration.[12] Therates of an ATRP increase with catalysts activity (KATRP),but under some conditions may become slower due toradical termination and a significant reduction of [CuI/L]/[ X-CuII/L] ratio, due to the persistent radical effect.[13]

Equation (2) illustrates how chain uniformity, i.e., dis-persity of molecular weights (Mw/Mn) of polymers pre-pared by ATRP, in the ideal case with the absence of

chain termination and transfer reactions, relates to theconcentration of dormant species (PnX) and deactivator(X-CuII) the rate constants of propagation (kp) and deac-tivation (kdeact), and monomer conversion (p).

[14]

MwMn

1 kpPnX

kdeactX CuII=L

2

p 1

2

Thus, for the same monomer, a catalyst that deactivatesthe growing chains faster will result in smaller kp/kdeactand will produce polymers with a narrower MWD,a smaller value for Mw/Mn.

[15] This value can also be de-

creased by increasing the concentration of deactivator, re-ducing the concentration of the dormant species (target-ing higher MW) and attaining higher conversion.

StructureReactivity Correlation in ATRP

Equilibrium constants in ATRP depend on the structureof the catalysts and alkyl halide (i.e., monomer) and alsoon the polymerization medium. Generally, ATRP equilib-rium constants increase strongly with solvent polarity, bystabilization of more polar CuII species, and also withtemperature. Deactivation rate constants are usually very

Krzysztof Matyjaszewski (PhD 1976 atthe Polish Academy of Sciences underProf. S. Penczek) is J. C. Warner Profes-sor of Natural Sciences and director ofthe Center for Macromolecular Engi-neering at Carnegie Mellon University.His main research interests includecontrolled/living radical polymeri-zation, catalysis, environmentalchemistry, and the synthesis of ad-vanced materials for optoelectronicand biomedical applications. He hasco-authored over 700 publicationscited over 50,000 times. In 2011, Maty-jaszewski received the Wolf Prize in Chemistry, Japanese PolymerSociety Award, ACS Hermann Mark Award, and ACS Applied Poly-mer Science Award. He is a member of the USA National Academyof Engineering, Russian Academy of Sciences, and Polish Academyof Sciences.

Scheme 1. ATRP equilibrium.

Isr. J. Chem. 2012, 52, 206 220 2012 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim www.ijc.wiley-vch.de 207

Atom Transfer Radical Polymerization : From Mechanisms to Applications
http://www.ijc.wiley-vch.de/http://www.ijc.wiley-vch.de/


3/15

high and may approach diffusion control limits (kdeact>107m1 s1) but they are less influenced by the structure ofthe involved reagents than the activation rate constant-s.[10a] Figures 1 and 2 show how kact varies with the ligandstructure and selected alkyl (pseudo)halides. The range of

kact spans over six orders of magnitude. An examinationof the structure of the ligands shows that the generalorder of Cu complex activity for ligands is: tetradentate(cyclic-bridged)> tetradentate (branched)> tetradentate

(cyclic)> tridentate>bidentate ligands. Bridged cyclam,tris(2-dimethylaminoethyl)amine (Me6TREN) and tris(2-

pyridylmethyl)amine (TPMA) are among most active and2,2-bipyridine and pyridineimine the least active.[16] Thenature of nitrogen atoms in ligands also plays a significantrole in the activity of the Cu complexes and follows theorder pyridine aliphatic amine> imine.[9] The presenceof a C2 bridge between N atoms generates complexeswith higher activities than ligands with C3 or C4 bridges.Steric effects around the Cu center are very important,with Me6TREN complex over 10,000 times more active

than for Et6TREN complex.[17]

Figure 1. ATRP activation rate constants for various ligands with EtBriB in the presence of Cu IBr in MeCN at 35 8C. N2: red, N3: black, N4:

blue; Amine/imine: solid, Pyridine: open, Mixed: left-half solid; Linear: &, Branched: ~, Cyclic: *. Reprinted with permission from Ref. [9].

Figure 2. ATRP activation rate constants for various initiators with Cu IX/PMDETA (X=Br or Cl) in MeCN at 35 8C: 38 : red, 28 : blue, 18 :

black; isothiocyanate/thiocyanate: left half-filled, chloride: open, bromide: filled, iodide: bottom half-filled; Amide: !, Benzyl: ~, Ester: &,Nitrile: *, Phenyl-ester: ^. Reprinted with permission from Ref. [18a].

208 www.ijc.wiley-vch.de 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Isr. J. Chem. 2012, 52, 206 220

vi w K. Matyjaszewski


4/15

The reactivity of alkyl halides is also quite differentand it is important to select a sufficiently reactive speciesfor efficient initiation of an ATRP. Figure 2 shows thatthe reactivity of alkyl halides follows the order of 38>28>18, in agreement with bond dissociation energyneeded for homolytic bond cleavage. Radical stabilization

is enhanced by the presence of an a

-cyano group, whichis more active than either an a-phenyl or ester group.The most active initiator is ethyl bromophenylacetatewith combined effects of benzyl and ester species, and isover 10,000 times more active than PEBr and over100,000 times more active than MBrP. Alkyl halide reac-tivities follow the order I>Br>Cl and they are muchhigher than alkyl pseudohalides.[18]

Radical Nature of the Propagating Species

The polymers in ATRP are formed by reaction of mono-

mers with propagating radicals, as in conventional RP.The living nature of ATRP originates in combining fastinitiation and concurrent growth of all chains via inter-mittent activation of dormant species catalyzed by Cucomplexes. Radical termination cannot be fully avoidedand the fraction of terminated chains depends on radicalconcentration, that is, the polymerization rate. Slower re-actions with lower [P*] result in smaller amounts of ter-minated chains.

There is abundant evidence that ATRP operates viaa radical mechanism: cross-propagation kinetics, reactivi-ty ratios;[19] regioselectivity and stereoselectivity;[19c,20] tac-ticity,[21] racemization, chemoselectivity with various traps

and transfer agents,[22] radical termination products, andkinetic isotope effects,[23] which all have values similar tothose in conventional RP. In addition, propagating radi-cals have been observed directly by EPR in the polymeri-zation of dimethacrylates[24] and EPR revealed the pres-

ence of X-CuII species resulting from the persistent radi-cal effect in ATRP.[25] Nevertheless, the multiple interre-lated equilibria involved in CRP, combined with intermit-tent activation of a relaxed dormant species, can result insome deviation in cross-propagation kinetics or branchingfrom those in a standard RP.[25g,26]

Therefore, ATRP is a radical-based process. However,the radicals can be formed from the dormant species byseveral pathways.

ISET vs. OSET

Mechanistically, halogen transfer from an alkyl halide tothe CuI complex can occur via either an outer-sphereelectron transfer (OSET), or an inner-sphere electron

transfer (ISET) i.e., atom transfer occurs by passingthrough a Cu-X-C transition state, which is formally alsoa single electron transfer process. OSET can proceed viaa stepwise manner with radical anion intermediates orthrough a concerted process with simultaneous dissocia-tion of the alkyl halide to a radical and an anion. Accord-ing to Marcus analysis of the electron transfer processes(Figure 3) OSET should have an energy barrier ~15 kcalmol1 higher than the values that were measured experi-mentally, that is, activation by OSET should be ~1010

times slower than ISET.[27]

The differences are much greater than any computa-tional or experimental errors and, consequently, a copper-

catalyzed ATRP occurs via concerted homolytic dissocia-tion of the alkyl halide. Moreover, the one-step dissocia-tive electron transfer to form a radical and an anion is en-ergetically more favorable than the two-step process viathe radical anion intermediates.[28]

Figure 3. Comparison of the free energies required for an ISET and a concerted OSET process for the reaction of bromoacetonitrile withCuI/TPMA catalyst in acetonitrile at 25 8C. Reprinted with permission from Ref. [27].




5/15

Initiating Systems for ATRP with ppm Copper

One limitation of a classic ATRP is the relatively largeamount of catalyst used to overcome the effect of termi-nation reactions that increase the concentration of theequivalent of the persistent radical, the X-CuIIL complex,

typically of the order of 0.11 mol%, relative to the mo-nomer. Therefore, the final products may contain a signifi-cant amount of residual metal. Several strategies were in-troduced to remove the catalyst from the final pro-duct,[7d,29] or to carry out the reactions with lower concen-trations of catalyst. However, as noted in an ATRP, as inany CRP, bimolecular radical termination typically in-volves 1 to 10% of chains. Each termination step leads toirreversible transformation of two equivalents of the acti-vator (CuIL in copper-mediated ATRP) into the higheroxidation state deactivating complex (X-CuIIL). There-fore, due to inevitable termination, the amount of catalystcould not be decreased to the desired lower concentra-

tions; for example, if the initial concentration of CuI is1 mol% relative to polymer chains, the polymerizationcould stop before 10% conversion, as the chains thathave participated in termination reactions have convertednearly all the CuI to the CuII deactivator, even at relative-ly low monomer conversion.

According to Equation (1), the rate of an ATRP doesnot depend on the absolute catalyst concentration, but onthe ratio of concentrations of activator and deactivator.Therefore, new ATRP initiation techniques were devel-oped focused on keeping this ratio constant with verystrongly diminished catalyst concentrations, down to ppmlevel. In these systems a very small amount of active cata-

lyst was used, and the activator lost due to radical termi-nation was constantly regenerated via a redox process.Simple reducing agents such as ascorbic acid, sugars,tin(II) octanoate, or amines were employed in ARGET(activators regenerated by electron transfer) ATRP,[30] orradical initiators in ICAR (initiators for continuous acti-vator regeneration) ATRP (Scheme 2).[31] ATRP can nowbe successfully conducted with very low amounts of cata-lyst. This approach has been now successfully extended toorganic synthesis radical addition and cyclization reac-tions based on ARGET and ICAR procedures.[32]

These new ATRP initiation techniques allow synthesis

of well-defined high MW polymers, markedly higher thanin traditional ATRP, because catalyst-related side reac-

tions that previously limited the polymer MW are mini-mized at lower catalyst concentrations. For many applica-tions, the removal of the small amount of catalyst is un-necessary, and when polymers containing no metal impur-ities are needed, purification is significantly simpler thanfor classical ATRP.

Zero-Valent Metals as Reducing Agents (andSupplemental Activators)

Metals such as Cu, Fe, Mg or Zn can also be used as thereducing agent.[33] In addition, they can act as direct sup-plemental activators. However, transition-metal com-plexes other than Cu, Ru, or Fe are generally relativelypoor deactivators. ATRP with Cu0 can be considered asa special case, because it produces in situ the deactivatingspecies. However, despite the significant amount of workon the role of Cu0 and the effect of polar solvents on the

kinetics of an ATRP,[34] it was proposed that the high ac-tivity observed form an ATRP in the presence of one ofthe most powerful ligands, Me6TREN, and Cu

0 (one ofseveral possible reducing agents) in polar solvents indicat-ed a change in mechanism[35] rather than merely reflectinga change in reaction conditions.[27,34b] The alternativemechanistic proposal for the ATRP of methyl acrylate inDMSO in the presence of Cu0 and Me6TREN

[35a] wasnamed SET LRP (single electron transfer living radicalpolymerization).[35c] The proposed mechanistic schemerelies on an outer-sphere electron transfer from Cu0 tothe alkyl halide to form the CuI species and radicalanions. The resulting CuI species was assumed to instan-

taneously disproportionate back to Cu0 and CuII species.The intermediate radical anions were proposed to cleaveto form propagating radicals and anions that associatewith the CuII species. Growing radicals were postulated tobe trapped exclusively by CuII species to form the dor-mant species and a CuI complex that would not activatethe dormant species but again instantaneously dispro-portionate.

Detailed kinetic and mechanistic studies show thatalkyl halides react preferentially with the soluble CuI/Me6TREN complex, due to its very high ATRP activity,rather than with solid Cu0 that has a relatively small sur-

face area. The Cu

0

serves as a reducing agent and actuallycomproportionates with CuII, formed as a persistent rad-ical in the radical termination process. Cu0 also slowlyreacts directly with alkyl halides, acting as a supplementalactivator.[33,34b] Only ~10% of CuBr/Me6TREN dispro-portionates in DMSO, and this degree of disproportiona-tion is even lower in mixtures containing the less polarmethyl acrylate monomer. Disproportionation/compro-portionation is a relatively slow process rather than in-stantaneous and since disproportionation is only partialin most systems, comproportionation dominates. CuI isalways present in the system and is the predominant acti-Scheme 2. ARGET and ICAR ATRP.




6/15


7/15

equilibrium constant and also CuIIX bond hydrolysis. Inheterogeneous systems, the catalyst complexes should besufficiently hydrophobic to be preferentially located in or-ganic phase and the choice of surfactant is important. An-other option that has recently been exemplified is usingreactive surfactants or dual reactive surfactants that are

anchored to particle surface and provide not only betterstability but also latent functionality.[42]

In addition to emulsion, miniemulsion, microemulsion,dispersion and precipitation polymerization, inverse mini-emulsion polymerization was also successful. It provideda new method for the synthesis and functionalization ofwell-defined water-soluble or cross-linked polymericnanoparticles.[43] Stable colloidal nanoparticles of well-controlled water-soluble poly(oligo(ethylene glycol) mon-omethyl ether methacrylate) (P(OEOMA)) homopoly-mers and copolymers were successfully synthesized by in-verse miniemulsion AGET ATRP at ambient tempera-tures.[44] This procedure allows preparation of well-de-

fined microgels/nanogels with narrow size distribution,a high degree of chain end functionality, a uniform cross-linked network, and properties (i.e. swelling ratio, degra-dation behavior and colloidal stability) superior to micro-gels prepared by conventional free radical polymeri-zation.[45] ATRP can be also carried out under homogene-ous conditions in water or in ionic liquids.[46]

Controlling Polymer Structure

ATRP, as other controlled/living polymerization meth-ods,[47] provides a versatile toolbox for preparation of var-

ious polymers with precisely controlled macromoleculararchitectures.[48] Since ATRP is a radical process, it is tol-

erant to many impurities and functionalities and can becarried out under undemanding conditions. Scheme 4 il-lustrates some examples of polymers with controlledchain composition, topology and functionality preparedby ATRP.

Concerning polymer composition, one can use ATRP

to prepare not only homopolymers but also statistical(random) copolymers from monomers with similar reac-tivities. However, if the comonomer reactivities are differ-ent, then gradient copolymers, with continuously variedcomposition along the polymer chain, can be formed.Gradient copolymers can also be formed from comono-mers with the same reactivity by using a feeding tech-nique.[49] Alternating or periodic copolymers can be pre-pared by copolymerization of comonomers with very lowreactivity ratios. They can also be formed if one less reac-tive comonomer, such as a simple alkene, is used in largeexcess. Complexation with a Lewis acid can additionallyenhance the tendency for alternation.[50]

Block and graft copolymers are the most common formof segmented copolymers. The former can be formed bysequential addition of comonomers to an ongoing reac-tion or by segmental coupling (using, for example, clickchemistry), use of mechanistic transformation (from/toATRP and ionic, coordination or polycondensation) oreven 2-directional concurrent growth using different poly-merization mechanisms for the preparation of each seg-ment.[51] An appropriate sequence of comonomer additionis very important when targeting block copolymeriza-tion,[52] moving from more active to less active monomers,but sometimes the efficiency of cross-propagation can beadditionally enhanced by the halogen exchange pro-

cess.[53] Radical polymerization is generally not efficientfor the control of stereochemistry and polymer tacticity.

Scheme 4. Examples of polymers with controlled architecture prepared by ATRP.




8/15

However, in the presence of Lewis acids such as Y(OTf)3and Yb(OTf)3 not only poly(dimethylacrylamide) withstrongly enhanced isotacticity was prepared but also firstblock copolymers with atactic and isotactic segments.[53a]

There are many examples of controlling polymer chaintopology to form branched architectures including star

polymers prepared using either core-first or arm-first ap-proaches.[54] The latter relies on using macroinitiators ormacromonomers in an ATRP with divinyl crosslinkingagents, under appropriate conditions; instead of formingmacroscopic gels/networks, stars are formed in high yieldand with high uniformity. Gels prepared by ATRP aredifferent from those made by conventional RP; due tohigher chain uniformity and formation of more regularnetwork structures they swell more and can be degradedmore easily.[46a,55]

One can also prepare comb-like polymers by graftingfrom, onto or through, using macromonomers. Verydense grafting along the copolymer backbone results in

macromolecular bottle-brush structures. These very largemacromolecules, with Mn values that can exceed severalmillions, can be not only visualized by AFM as singlemolecules but can also be used as sensors and model ten-sile machines.[56]

ATRP has been also used for synthesis of randomlybranched and hyperbranched polymers and even for den-dritic systems. Cyclic polymers have been prepared byATRP or ATRP and nitroxide coupling.[57]

ATRP is tolerant to many functional groups such as hy-droxy, cyano, amino, amido, esters and others.[48f] Acidsshould be protected to prevent protonation of N-based li-gands. This can be accomplished at higher pH or in the

presence of amines that scavenge protons. Functionalitiescan be incorporated via monomers, initiators or throughpost-polymerization reactions. One of many advantagesof ATRP is the availability of various functional initiatorsand known procedures for the facile preparation of multi-functional systems, for example, by simple esterificationreactions to form 2-bromopropionates or 2-bromoisobuty-rates. The list of suitable starting materials includes notonly simple organic polyols, but also natural products andflat, concave or convex inorganic surfaces.[7 g,58] Moreover,displacement of halides from the chain ends provides notonly a variety of homo and hetero telechelics but also

many multifunctional stars or (hyper)branched systemswith peripheral functionalities.[59]

The final properties of many materials are defined notonly by architecture of a single macromolecule but, asshown in Scheme 4, by their self-assembly to variousnanostructured materials. In addition, controlled pre-as-sembly is also possible by surface patterning, graftingfrom various functional surfaces and even from linearpolymer chains. There are many morphologies availablefrom self-assembly of block copolymers, depending onthe block order, interaction parameters and volume frac-tions that constitute spheres, cylinders and lamellae in

various combinations.[60] In the next section, it will beshown that in addition to segment size, segment dispersitycan also become a very important factor in defining mor-phological features.

Effect of Molecular Weight Distribution onMorphology of Diblock Copolymers Prepared byATRP

It has been theoretically predicted and experimentallyconfirmed that molecular weight distribution (MWD) ordispersity can affect polymer morphology.[61] As indicatedearlier in Equation (2), ARGET ATRP should be an effi-cient method to control MWD by changing the amountof CuII catalyst in the system. With less Cu deactivatorpresent in the reaction medium chains grow longer seg-ments at each intermittent activation step and will pro-duce polymers with higher dispersity. In order to analyze

the effect of dispersity on morphology of block copoly-mers, a polystyrene (PS) macroinitiator block was pre-pared by ARGET ATRP of S with 50 ppm of CuBr2/Me6TREN catalyst in the presence of Sn(EH)2 as reduc-ing agent, resulting in PS with Mn=31,100, Mw/Mn=1.11.[62] The PS was then chain extended by polymeri-zation of methyl acrylate with 50 and 5 ppm of CuBr 2/Me6TREN catalyst resulting in formation of a block co-polymer with narrow distribution of both blocks, (PS-PMA)NN Mn=47, 200, Mw/Mn=1.11, and a copolymerwith narrow distribution of the first block and broaderdistribution of the second one, (PS-PMA)NB Mn=51,700PDI=1.13. PMA homopolymers prepared under identical

conditions had the following properties: PMAN (ARGETATRP with 50 ppm Cu catalyst, Mn=18,300, Mw/Mn=1.11) and PMAB (ARGET ATRP with 5 ppm of Cu cata-lyst, Mn=18,500, Mw/Mn=1.77). Blocking efficiency forboth systems were similar, as determined by liquid chro-matography. The amount of residual PS homopolymerwas 4 % for (PS-PMA)NN, and 7 % for (PS-PMA)NB.

[62]

However, in spite of the overall similar compositions, themorphologies of the two block copolymers were very dif-ferent. Figure 5 shows bright field electron micrographsof PS-PMA samples. The block copolymer (PS-PMA)NNshowed a typical cylindrical microstructure whereas (PS-

PMA)NB showed a hexagonally perforated lamellar mi-crostructure. The latter, typically a metastable morpholo-gy, was stable after annealing at 1208C for 72 h. It is pos-sible that broader MWD of the PMA segment stabilizesthe bicontinuous morphology, as the lower MW fractionmay tend to form a spherical microstructure and higherMW fraction a lamellar microstructure, thereby findinga compromise in a hexagonally perforated lamellar mor-phology.

This study was extended to other PS-PMA systems assummarized in Scheme 5. Large differences were ob-served for several block copolymers. Increased dispersity




9/15

converted cylindrical morphology to uneven lamellaewith the ratio of PS to PMA segments 70B/30N or 16N/84B.

In some other cases disordered cylinders were observed.

These results indicate that MWD becomes an importanttool to control polymer morphology and gives access tostable bicontinuous microstructures, which would be espe-cially interesting for membranes, biomedical applicationsand conducting polymers including photovoltaics andbulk heterojunction systems.[63] However, it should be

noted that in some cases increased dispersity may also en-hance formation of a fraction of a homopolymer. Thiscan lead to enrichment of one of the phases with a homo-polymer and increased dimensions of the microphase sep-arated domains.[64]

The nanostructured morphologies observed in blockcopolymers may be thermodynamically stable but mayalso be kinetically trapped. Therefore, processing of poly-mers with complex architecture is very important as thiswill also affect the properties of the final materials. Animportant challenge for materials science is how to corre-late molecular structure with macroscopic properties.[48a,65]

Processing is a very important link between synthesis and

properties, and hence applications. Another importantfactor is an appropriate balance between cost and perfor-mance. New initiating systems for ATRP such asARGET and ICAR not only reduce the amount ofcopper, which lowers cost and environmental impact, butallows control over dispersity and can lead to materialswith new nanostructured morphologies. There are severalother important issues in material development, such asthe fraction of unfunctionalized (dead) chains, theamount of missing arms in star polymers, or the presenceof non-extended segments in block copolymers. It will bebeneficial if the final product can tolerate such imperfec-tions but it is also important to quantify to what extent

they will affect material properties. Scheme 6 illustrates

Figure 5. Bright field electron micrographs of PS-PMA samplesafter 72 h thermal annealing at T=120 8C and staining with RuO4(PS is the dark domain); a: (PS-PMA)NN, revealing cylindrical micro-

structure imaged along [001]; b: (PS-PMA)NB, revealing hexagonallyperforated lamellar microstructure imaged approximately normal

to the layer direction. Inset shows plan view revealing the hexago-

nal arrangement of PS perforations. Reprinted with permission

from Ref. [62].

Scheme 5. Examples of morphologies for the PS-PMA block copolymers with one of the block with narrow and the other with broadMWD.




10/15

a concept of retro-designing polymers with controlled ar-chitecture, taking into account contributions from con-trolled processing.

Current and Future Applications of PolymersMade by ATRP

Polymers prepared by ATRP have been commerciallyproduced in US, Japan and Europe since 2002. [66] Poly-mers made by ATRP find use in many applications, in-cluding sealants,[67] lubricants,[68] oil additives with im-proved thickening behavior, shear stability, and tempera-ture independent viscosity.[69] Telechelic copolymers,[70]

gradient copolymers,[71] block copolymers[72] and combpolymers can be used as wetting agents, pigment disper-sants[73] and various surfactants.[74] The pigment stabilizerscan be used for coating compounds, prints, images, inks

or lacquers and other disperse systems.[73b,75] A potentialloss of transparency due to scattering from the embeddedparticles, a consequence of the significantly different re-fractive index of inorganic materials and organic matrixmaterials, can be suppressed by means of appropriate sur-face modification of the particle using ATRP to matchthe effective refractive index of the resulting coreshellparticle to the refractive index of the embeddingmedium.[76]

End-functionalized polymers can be used for blendcompatibilization [77] during reactive processing and inmany thermosetting compositions; for example, epoxy-

functional polymers and functional materials form thebasis of the majority of products prepared for dispersant,coating, adhesive, and sealant, etc. applications. Severalpolyolefin segmented copolymers containing polarblocks/grafts were developed to provide surface hydrophi-licity, conductivity and antibacterial properties to materi-als.[78]

A higher value application, based on ATRP functional-ization of a solid particle, is the development of the sta-tionary phase of nano-engineered analytical immobilizedmetal affinity chromatography columns for separation ofproteins and synthetic prion peptides.[79]

Core-shell-type hyperbranched polymers form resistswith improved adhesion properties and surface smooth-ness that are suitable in photolithography and nano-fabri-cation when spin-coated on a Si wafer and baked to forma 100 nm thick film showing 254 nm UV sensitivity of2 mJcm2 allowing manufacture of the semiconductor de-

vices.

[80]

Polar thermoplastic elastomers can be prepared bya continuous bulk ATRP process[81] or by sequential addi-tion of monomers to an ongoing emulsion ATRP.[82] Themajor benefit of polar TPEs is that they are oil resistantand recyclable, that is, it is possible to injection mold thematerials and minimize waste. Thermoplastic elastomers(TPEs) can be synthesized in a one-pot process usingARGET ATRP. PS-PEA-PS and PMMA-PBA-PMMATPEs were made in such a process. [81] Since multi-func-tional initiators are easily prepared and polymer topologyaffects properties, other non-linear architectures can beconsidered; e.g., star-blocks, grafts, or brushes with block

side chains.[83] The properties of PBA-b-PAN 3-arm starblock copolymers[84] show that these polar materials withproperties that are easily adjustable, based on composi-tion, retain their useful properties over a broad tempera-ture range, from 50 to +270 8C.

Bottle-brush macromolecules with a very long back-bone and densely grafted PnBA side chains behave as su-persoft elastomers with an environmentally stable ultralow modulus plateau in the soft gel range of 1 kPa.[85] Theplateau modulus is much lower than seen for typical poly-meric rubbers, which can be attributed to the large frac-tion of the short dangling chains in the system. Suchchains provide significant mobility, making the material

extremely soft and also excellent ionic conductors.[86]

ATRP provides many advantages in grafting froma flat surface reaction as the thickness of the tetheredpolymer brush can be precisely controlled by systematicvariation of grafting density and DPn of the tetheredpolymers.[87] Modification of surfaces with thin polymerfilms can be used to tailor the surface properties such ashydrophilicity/-phobicity, biocompatibility, adhesion, ad-sorption, corrosion resistance and friction. The surfaceproperties can be tuned by the tethering of block copoly-mers, where the composition and size of each polymersegment affects the morphology and behavior of the poly-

mer brushes.

[88]

Grafted chains in such a high-densitypolymer brush are highly extended, even to their fully ex-tended lengths in good solvent. A high-density polymerbrush has a different set of characteristic properties, inboth swollen and dry states, that are quite different fromthose of the semi-dilute or moderately dense polymerbrushes previously studied.[89] Polymers with quaternaryammonium ions (PQA) effectively kill cells and spores bydisrupting cell membranes. Monomers such as 2-dimethy-laminoethyl methacrylate (DMAEMA) or 4-vinylpyridinethat can be quaternized, thereby providing biocidal activi-ty, were polymerized by ATRP.[90] Antimicrobial surfaces

Scheme 6. Retro-design of targeted materials properties.




11/15

were prepared by grafting from[78a,91] or grafting onto sur-faces,[91a,92] blended with[93] or deposited on other poly-mers.[94]

Functional copolymers prepared by ATRP were usedfor drug delivery.[22g,95] The diblock copolymer poly(2-methacryloyloxyethylphosphorylcholine- b-2-(diethylami-

no)ethyl methacrylate) dissolved in acidic solutions, dueto protonation of the amino residues, but formed micellesat pH 8. The diblock copolymer micelles are biocompat-ible and show considerable promise for drug delivery ap-plications.[95a] Triblock acrylate-based block copolymerswere prepared by ATRP as matrices for paclitaxel deliv-ery from coronary stents.[96] Stable biodegradable poly-(oligo (ethylene oxide) monomethyl ether methacrylate)nanogels, cross-linked with cleavable disulfide linkages,were prepared by ATRP in inverse miniemulsion.[97]

These nanogels could be used for targeted drug deliveryscaffolds for biomedical applications since they can be de-graded into lower molecular weight polymers to release

the encapsulated (bio)molecules.[45,95d] Nanostructuredhybrid hydrogels with sizes ca. 100 nm were incorporatedinto larger three-dimensional matrix generating drug de-livery scaffolds suitable for tissue engineering applica-tions.[22g] Poly(ethylene glycol) (PEG) star polymers con-taining GRGDS peptide sequences on the star peripherywere synthesized by ATRP of poly(ethylene glycol)methyl ether methacrylate via an arm-first method.These star polymers were biocompatible, with greaterthan 90% cell viability after 24 h of incubation withMC3T3-E1.4 cells. Rapid cellular uptake of PEG starpolymers with GRGDS peptides, essentially 100% within15 min, was observed by flow cytometry, suggesting en-

hanced delivery potential of these functional star poly-mers.[98] Natural products were successfully covalentlyconjugated with polymers prepared by ATRP via graftingfrom and grafting onto procedures.[46b,c,57,99]

Summary and Outlook

ATRP is among the most versatile synthetic techniquesfor preparation of polymers with precisely controlled ar-chitecture and site specific functionality. The prerequisitefor the precise synthesis is an accurate mechanistic under-

standing of the ATRP process through detailed structurereactivity correlation including the effect of solvent, tem-perature and pressure on the reaction. This fundamentalunderstanding helps in the design of better catalysts, de-velopment of procedures to reduce the amount of transi-tion metal, and the ability to carry out environmentallybenign reactions. The second important area is correla-tion between controlled structure and properties of theobtained polymers. This relationship includes not onlychain topology, composition and functionality but alsochain length uniformity. An interesting opportunity is of-fered by incorporating controlled heterogeneities, such as

designed molecular weight distribution, branching andcomposition in the form of gradients, into the final prod-uct. A combination of controlled synthesis with con-trolled processing paves many efficient avenues for devel-opment of advanced materials with new targeted proper-ties that can benefit our society.

Acknowledgements

Creative contributions and discussions with many collabo-rators and over 100 postdocs and graduate students atCarnegie Mellon University are gratefully acknowledged.Financial support from NSF (DMR 09-69301, CHE 10-26060, DOE ER 45998) and CRP Consortium is acknowl-edged.

References

[1] K. Matyjaszewski, Y. Gnanou, L. Leibler, MacromolecularEngineering, Wiley-VCH, Weinheim,2007.

[2] a) M. Szwarc, Nature 1956, 176, 11681169; b) M. Szwarc,M. Levy, R. Milkovich, J. Am. Chem. Soc. 1956, 78, 2657.

[3] Various living polymerizations and their application to thesynthesis of block copolymers are covered in the followingreview articles: a) K. Matyjaszewski, A. H. E. Mueller,Progr. Polym. Sci. 2006, 31, 10391040; b) J. Smid, M. VanBeylen, T. E. Hogen-Esch, Progr. Polym. Sci. 2006, 31,10411067; c) N. Hadjichristidis, H. Iatrou, M. Pitsikalis, J.Mays, Progr. Polym. Sci. 2006, 31, 10681132; d) Y. Yagci,M. A. Tasdelen, Progr. Polym. Sci. 2006, 31, 11331170;e) C. W. Bielawski, R. H. Grubbs, Progr. Polym. Sci. 2007,32, 129; f) G. J. Domski, J. M. Rose, G. W. Coates, A. D.

Bolig, M. Brookhart, Progr. Polym. Sci. 2007, 32, 3092;g) W. A. Braunecker, K. Matyjaszewski, Progr. Polym. Sci.2007, 32, 93 146; h) T. Yokozawa, A. Yokoyama, Progr.Polym. Sci. 2007, 32, 147172; i) D. Baskaran, A. H. E. Mu-eller, Progr. Polym. Sci. 2007, 32, 173219; j) E. J. Goethals,F. Du Prez, Progr. Polym. Sci. 2007, 32, 220 246; k) S. Penc-zek, M. Cypryk, A. Duda, P. Kubisa, S. Slomkowski, Progr.Polym. Sci. 2007,32, 247 282.

[4] K. Matyjaszewski, T. P. Davis, Handbook of Radical Poly-merization, Wiley, Hoboken, 2002.

[5] a) K. Matyjaszewski,J. Phys. Org. Chem. 1995, 8, 197207;b) A. Goto, T. Fukuda, Prog. Polym. Sci. 2004, 29, 329 385.

[6] W. A. Braunecker, K. Matyjaszewski, Prog. Polym. Sci.2007, 32, 93146.

[7] a) J.-S. Wang, K. Matyjaszewski, J. Am. Chem. Soc. 1995,117, 5614 5615; b) K. Matyjaszewski, J. Xia, Chem. Rev.2001, 101, 29212990; c) M. Kamigaito, T. Ando, M. Sawa-moto, Chem. Rev. 2001, 101, 3689; d) N. V. Tsarevsky, K.Matyjaszewski, Chem. Rev. 2007, 107, 2270 2299; e) A. E.Smith, X. Xu, C. L. McCormick, Prog. Polym. Sci. 2010, 35 ,4593; f) A. Debuigne, R. Poli, C. Jerome, R. Jerome, C.Detrembleur, Prog. Polym. Sci. 2009, 34, 211239; g) K.Matyjaszewski, N. V. Tsarevsky, Nat. Chem. 2009, 1, 276288.

[8] F. di Lena, K. Matyjaszewski, Prog. Polym. Sci. 2010, 35,9591021.

[9] W. Tang, K. Matyjaszewski, Macromolecules2006,39, 4953 4959.




12/15

[10] a) W. Tang, Y. Kwak, W. Braunecker, N. V. Tsarevsky, M. L.Coote, K. Matyjaszewski, J. Am. Chem. Soc. 2008, 130,1070210713; b) K. Matyjaszewski, H.-j. Paik, P. Zhou, S. J.Diamanti, Macromolecules 2001, 34, 51255131.

[11] W. Tang, N. V. Tsarevsky, K. Matyjaszewski, J. Am. Chem.Soc.2006, 128, 15981604.

[12] N. Bortolamei, A. A. Isse, V. B. Di Marco, A. Gennaro, K.

Matyjaszewski, Macromolecules2010, 43, 92579267.[13] H. Fischer,Chem. Rev. 2001, 101, 35813610.[14] a) K. Matyjaszewski, Macromol. Symp. 1996, 111, 4761;

b) G. Litvinenko, A. H. E. Mueller, Macromolecules 1997,30, 12531266.

[15] T. E. Patten, J. H. Xia, T. Abernathy, K. Matyjaszewski, Sci-ence1996, 272, 866 868.

[16] a) K. Matyjaszewski, T. E. Patten, J. H. Xia, J. Am. Chem.Soc. 1997, 119, 674 680; b) J. H. Xia, K. Matyjaszewski,Macromolecules 1997, 30, 7697 7700; c) J. H. Xia, S. G.Gaynor, K. Matyjaszewski, Macromolecules 1998, 31, 59585959; d) K. Matyjaszewski, B. Gobelt, H. J. Paik, C. P. Hor-witz, Macromolecules2001, 34, 430 440.

[17] Y. Inoue, K. Matyjaszewski, Macromolecules 2004, 37,40144021.

[18] a) W. Tang, K. Matyjaszewski, Macromolecules 2007, 40,18581863; b) C.-Y. Lin, S. R. A. Marque, K. Matyjaszew-ski, M. L. Coote, Macromolecules2011, 44, 75687583.

[19] a) D. M. Haddleton, M. C. Crossman, K. H. Hunt, C. Top-ping, C. Waterson, K. G. Suddaby, Macromolecules 1997, 30,39923998; b) T. Nishikawa, T. Ando, M. Kamigaito, M. Sa-wamoto,Macromolecules 1997, 30, 22442248; c) S. V. Are-hart, K. Matyjaszewski, Macromolecules 1999, 32, 22212231; d) K. Matyjaszewski, M. J. Ziegler, S. V. Arehart, D.Greszta, T. Pakula, J. Phys. Org. Chem. 2000, 13, 775 786;e) G. Chambard, B. Klumperman, ACS Symp. Ser. 2000,768, 197210; f) M. J. Ziegler, K. Matyjaszewski, Macromo-lecules2001, 34, 415 424.

[20] B. Otazaghine, B. Boutevin, P. Lacroix-Desmazes, Macro-

molecules2002, 35, 76347641.[21] a) H. Takahashi, T. Ando, M. Kamigaito, M. Sawamoto,Macromolecules 1999, 32, 64616465; b) J.-S. Wang, K. Ma-tyjaszewski, Macromolecules 1995, 28, 79017910.

[22] a) K. Matyjaszewski, H.-j. Paik, D. A. Shipp, Y. Isobe, Y.Okamoto, Macromolecules 2001, 34, 3127 3129; b) K. Ma-tyjaszewski, Macromolecules 1998, 31, 4710 4717; c) S. G.Gaynor, J. Qiu, K. Matyjaszewski, Macromolecules 1998, 31,59515954; d) J. Qiu, S. G. Gaynor, K. Matyjaszewski, Mac-romolecules 1999, 32, 28722875; e) J. P. A. Heuts, R. Mal-lesch, T. P. Davis, Macromol. Chem. Phys. 1999, 200, 13801385; f) S. G. Roos, A. H. E. Muller, Macromol. RapidCommun. 2000, 21, 864 867; g) S. A. Bencherif, N. R.Washburn, K. Matyjaszewski, Biomacromolecules 2009, 10,24992507.

[23] D. A. Singleton, D. T. Nowlan, III, N. Jahed, K. Matyjas-zewski, Macromolecules2003,36, 86098616.

[24] Q. Yu, F. Zeng, S. Zhu, Macromolecules 2001, 34, 16121618.

[25] a) A. Kajiwara, K. Matyjaszewski, M. Kamachi,Macromole-cules 1998, 31, 56955701; b) A. Kajiwara, K. Matyjaszew-ski, Macromol. Rapid Commun. 1998, 19, 319 321; c) A.Kajiwara, K. Matyjaszewski, Macromolecules 1998, 31,3489 3493; d) A. Kajiwara, K. Matyjaszewski, Polym. J.1999, 31, 7075; e) A. Kajiwara, K. Matyjaszewski, M. Ka-machi, ACS Symp. Ser. 2000, 768, 6881; f) K. Matyjaszew-ski, A. Kajiwara, Macromolecules 1998, 31, 548550; g) K.Matyjaszewski, Macromolecules2002, 35, 67736781.

[26] a) H. Shinoda, K. Matyjaszewski, L. Okrasa, M. Mierzwa, T.Pakula, Macromolecules 2003, 36, 47724778; b) D. Konko-lewicz, S. Sosnowski, D. R. DHooge, R. Szymanski, M.-F.Reyniers, G. B. Marin, K. Matyjaszewski, Macromolecules2011, 44, 83618373.

[27] C. Y. Lin, M. L. Coote, A. Gennaro, K. Matyjaszewski, J.Am. Chem. Soc.2008, 130, 1276212774.

[28] A. A. Isse, A. Gennaro, C. Y. Lin, J. L. Hodgson, M. L.Coote, T. Guliashvili, J. Am. Chem. Soc. 2011, 133, 62546264.

[29] a) Y. Shen, H. Tang, S. Ding, Prog. Polym. Sci. 2004, 29,10531078; b) G. Kickelbick, H. J. Paik, K. Matyjaszewski,Macromolecules 1999, 32, 29412947; c) L. Mueller, K. Ma-tyjaszewski, Macromol. React. Eng.2010, 4, 180 185.

[30] a) W. Jakubowski, K. Matyjaszewski, Angew. Chem. 2006,118, 4594; Angew. Chem. Int. Ed. 2006, 45, 4482; b) W. Ja-kubowski, K. Min, K. Matyjaszewski, Macromolecules 2006,39, 39; c) Y. Yamamura, K. Matyjaszewski, J. Macromol.Sci. Pure Appl. Chem. 2007, 44, 10351039; d) K. Min, H.Gao, K. Matyjaszewski, Macromolecules 2007, 40, 17891791; e) H. Dong, K. Matyjaszewski, Macromolecules 2008,41, 68686870; f) Y. Kwak, K. Matyjaszewski, Polym. Int.2009, 58, 242 247.

[31] K. Matyjaszewski, W. Jakubowski, K. Min, W. Tang, J.Huang, W. A. Braunecker, N. V. Tsarevsky, Proc. Natl.Acad. Sci. USA2006, 103, 1530915314.

[32] T. Pintauer, K. Matyjaszewski, Chem. Soc. Rev. 2008, 37,10871097.

[33] Y. Zhang, Y. Wang, K. Matyjaszewski, Macromolecules2011, 44, 683 685.

[34] a) B. E. Woodworth, Z. Metzner, K. Matyjaszewski, Macro-molecules 1998, 31, 79998004; b) K. Matyjaszewski, N. V.Tsarevsky, W. A. Braunecker, H. Dong, J. Huang, W. Jaku-bowski, Y. Kwak, R. Nicolay, W. Tang, J. A. Yoon, Macro-molecules 2007, 40, 77957806; c) W. A. Braunecker, N. V.Tsarevsky, A. Gennaro, K. Matyjaszewski, Macromolecules

2009, 42, 63486360.[35] a) V. Percec, T. Guliashvili, J. S. Ladislaw, A. Wistrand, A.

Stjerndahl, M. J. Sienkowska, M. J. Monteiro, S. Sahoo, J.Am. Chem. Soc. 2006, 128, 14156 14165; b) G. Lligadas, V.Percec, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 31743181; c) B. M. Rosen, V. Percec, Chem. Rev. 2009, 109,50695119.

[36] M. Zhong, K. Matyjaszewski, Macromolecules 2011, 44,26682677.

[37] A. J. D. Magenau, N. C. Strandwitz, A. Gennaro, K. Maty-jaszewski, Science 2011, 332, 81 84.

[38] a) J. Qiu, K. Matyjaszewski, L. Thouin, C. Amatore,Macro-mol. Chem. Phys. 2000, 201, 16251631; b) N. Bortolamei,A. A. Isse, A. J. D. Magenau, A. Gennaro, K. Matyjaszew-

ski,Angew. Chem. Int. Ed.2011,50, 11391 11394.[39] M. Nasser-Eddine, C. Delaite, P. Dumas, R. Vataj, A.

Louati,Macromol. Mater. Eng. 2004,289, 204 207.[40] K. Min, K. Matyjaszewski, Centr. Eur. J. Chem. 2009, 7,

657674.[41] a) K. Min, S. Yu, H.-i. Lee, L. Mueller, S. S. Sheiko, K. Ma-

tyjaszewski, Macromolecules 2007, 40, 65576563; b) Y.

Kagawa, P. B. Zetterlund, H. Minami, M. Okubo, Macro-mol. Theory Simul. 2006, 15, 608613; c) P. B. Zetterlund,Y. Kagawa, M. Okubo, Macromolecules 2009, 42, 24882496; d) P. B. Zetterlund, Y. Kagawa, M. Okubo, Chem.Rev. 2008, 108, 3747 3794; e) M. F. Cunningham, Prog.Polym. Sci.2008,33, 365 398.




13/15

[42] a) W. Li, K. Min, K. Matyjaszewski, F. Stoffelbach, B. Char-leux, Macromolecules2008,41, 6387 6392; b) W. Li, K. Ma-tyjaszewski, K. Albrecht, M. Moller, Macromolecules 2009,42, 82288233; c) W. Li, K. Matyjaszewski, J. Am. Chem.Soc. 2009, 131, 1037810379; d) W. Li, J. A. Yoon, K. Ma-tyjaszewski, J. Am. Chem. Soc. 2010, 132, 78237825; e) W.Li, K. Matyjaszewski, Macromol. Rapid Commun. 2011, 32,

74 81; f) W. Li, K. Matyjaszewski, Macromolecules 2011,44, 55785585; g) K. Min, H. F. Gao, K. Matyjaszewski, J.Am. Chem. Soc. 2005, 127, 38253830; h) K. Min, K. Maty-jaszewski, Macromolecules 2005, 38, 81318134.

[43] J. K. Oh, C. Tang, H. Gao, N. V. Tsarevsky, K. Matyjaszew-ski, J. Am. Chem. Soc. 2006, 128, 55785584.

[44] J. K. Oh, F. Perineau, K. Matyjaszewski, Macromolecules2006, 39, 80038010.

[45] J. K. Oh, R. Drumright, D. J. Siegwart, K. Matyjaszewski,Prog. Polym. Sci. 2008, 33, 448 477.

[46] a) K. Matyjaszewski, K. L. Beers, A. Kern, S. G. Gaynor, J.Polym. Sci. Part A: Polym. Chem. 1998, 36, 823 830;b) J. C. Peeler, B. F. Woodman, S. Averick, S. J. Miyake-Stoner, A. L. Stokes, K. R. Hess, K. Matyjaszewski, R. A.Mehl, J. Am. Chem. Soc. 2010, 132, 1357513577; c) S. E.

Averick, A. J. D. Magenau, A. Simakova, B. F. Woodman,A. Seong, R. A. Mehl, K. Matyjaszewski, Polym. Chem.

2011, 2, 14761478; d) T. Sarbu, K. Matyjaszewski, Macro-mol. Chem. Phys. 2001, 202, 33793391.

[47] Controlled and Living Polymerizations: From Mechanismsto Materials (Eds.: A. H. E. Mueller, K. Matyjaszewski),Wiley-VCH, Weinheim,2009, p. 612.

[48] a) K. Matyjaszewski, Prog. Polym. Sci. 2005, 30, 858875;

b) J. Qiu, B. Charleux, K. Matyjaszewski, Prog. Polym. Sci.2001, 26, 2083 2134; c) H. Gao, K. Matyjaszewski, Prog.Polym. Sci. 2009, 34, 317350; d) H.-i. Lee, J. Pietrasik, S. S.Sheiko, K. Matyjaszewski, Prog. Polym. Sci. 2010, 35, 2444; e) S. S. Sheiko, B. S. Sumerlin, K. Matyjaszewski, Prog.Polym. Sci. 2008, 33, 759785; f) V. Coessens, T. Pintauer,

K. Matyjaszewski, Prog. Polym. Sci. 2001, 26, 337 377.[49] a) K. Matyjaszewski, M. J. Ziegler, S. V. Arehart, D. Gresz-

ta, T. Pakula, J. Phys. Org. Chem. 2000, 13, 775 786;

b) K. A. Davis, K. Matyjaszewski, in Statistical, Gradient,Block and Graft Copolymers by Controlled/Living Radical

Polymerizations, Vol. 159, 2002, pp. 1 169; c) A. I. Buzin,M. Pyda, P. Costanzo, K. Matyjaszewski, B. Wunderlich,Polymer 2002, 43, 55635569; d) W. Jakubowski, A. Juhari,A. Best, K. Koynov, T. Pakula, K. Matyjaszewski, Polymer2008, 49, 15671578; e) S. B. Lee, A. J. Russell, K. Matyjas-zewski, Biomacromolecules 2003, 4, 13861393; f) K. Min,J. K. Oh, K. Matyjaszewski, J. Polym. Sci. Part A: Polym.Chem. 2007, 45, 14131423; g) K. E. Min, M. Li, K. Maty-

jaszewski, J. Polym. Sci. Part A: Polym. Chem. 2005, 43,

3616 3622; h) T. Pakula, K. Matyjaszewski, Macromol.Theory Simul. 1996, 5, 9871006; i) S. Qin, J. Saget, J. Pyun,S. Jia, T. Kowalewski, K. Matyjaszewski, Macromolecules2003, 36, 89698977.

[50] J. F. Lutz, B. Kirci, K. Matyjaszewski, Macromolecules 2003,36, 31363145.

[51] a) K. A. Davis, B. Charleux, K. Matyjaszewski, J. Polym.Sci. Part A: Polym. Chem. 2000, 38 , 22742283; b) S. Coca,H. J. Paik, K. Matyjaszewski, Macromolecules 1997, 30,65136516; c) S. Coca, K. Matyjaszewski, Macromolecules

1997, 30, 2808 2810; d) S. G. Gaynor, K. Matyjaszewski,Macromolecules 1997, 30, 4241 4243; e) H. Shinoda, K.Matyjaszewski, Macromolecules2001, 34, 62436248.

[52] a) K. Matyjaszewski, Macromolecules 1993, 26, 17871788;b) J. Pyun, K. Matyjaszewski, T. Kowalewski, D. Savin, G.Patterson, G. Kickelbick, N. Huesing, J. Am. Chem. Soc.2001, 123, 94459446; c) T. Kowalewski, N. V. Tsarevsky, K.Matyjaszewski, J. Am. Chem. Soc. 2002, 124, 1063210633.

[53] a) J. F. Lutz, D. Neugebauer, K. Matyjaszewski, J. Am.Chem. Soc. 2003, 125, 6986 6993; b) K. Matyjaszewski,

D. A. Shipp, G. P. McMurtry, S. G. Gaynor, T. Pakula, J.Polym. Sci. Part A: Polym. Chem. 2000, 38, 2023 2031;c) K. Matyjaszewski, J. Macromol. Sci. Part A: Pure AppChem.1997, A34, 17851801; d) K. Matyjaszewski, S. M. Jo,H. J. Paik, D. A. Shipp, Macromolecules 1999, 32, 64316438; e) K. Matyjaszewski, S. Gaynor, D. Greszta, D. Mar-dare, T. Shigemoto, J. Phys. Org. Chem. 1995, 8, 306315;f) C.-H. Peng, J. Kong, F. Seeliger, K. Matyjaszewski, Mac-romolecules2011, 44, 75467557.

[54] a) X. Zhang, J. H. Xia, K. Matyjaszewski, Macromolecules2000, 33, 23402345; b) H. F. Gao, K. Matyjaszewski, Mac-romolecules 2006, 39, 49604965; c) J. H. Xia, X. Zhang, K.Matyjaszewski, Macromolecules 1999, 32, 4482 4484; d) K.Matyjaszewski, Polym. Int. 2003, 52, 1559 1565; e) H. F.

Gao, N. V. Tsarevsky, K. Matyjaszewski, Macromolecules2005, 38, 59956004; f) H. F. Gao, K. Matyjaszewski, Mac-romolecules 2006, 39, 31543160; g) H. F. Gao, S. Ohno, K.Matyjaszewski, J. Am. Chem. Soc. 2006, 128, 1511115113;h) H. F. Gao, K. Matyjaszewski, Macromolecules 2008, 41,11181125; i) H. Gao, K. Matyjaszewski, J. Am. Chem. Soc.2007, 129, 1182811834.

[55] a) H. Gao, K. Min, K. Matyjaszewski,Macromolecules 2007,40, 77637770; b) P. Polanowski, J. K. Jeszka, W. Li, K. Ma-

tyjaszewski, Polymer2011, 52, 50925101.[56] a) K. Matyjaszewski, S. H. Qin, J. R. Boyce, D. Shirvanyants,

S. S. Sheiko, Macromolecules 2003, 36, 18431849; b) S. S.Sheiko, S. A. Prokhorova, K. L. Beers, K. Matyjaszewski,I. I. Potemkin, A. R. Khokhlov, M. Moller, Macromolecules2001, 34, 83548360; c) S. H. Qin, K. Matyjaszewski, H. Xu,

S. S. Sheiko, Macromolecules 2003, 36, 605612; d) J. Pyun,T. Kowalewski, K. Matyjaszewski, Macromol. RapidCommun.2003, 24, 10431059; e) S. S. Sheiko, F. C. Sun, A.

Randall, D. Shirvanyants, M. Rubinstein, H. Lee, K. Maty-jaszewski, Nature2006, 440, 191 194.

[57] R. Nicolay, K. Matyjaszewski, Macromolecules 2011, 44,240247.

[58] a) K. Matyjaszewski, P. J. Miller, N. Shukla, B. Immaraporn,A. Gelman, B. B. Luokala, T. M. Siclovan, G. Kickelbick, T.Vallant, H. Hoffmann, T. Pakula, Macromolecules 1999, 32,8716 8724; b) J. Pyun, K. Matyjaszewski, Chem. Mater.2001, 13, 34363448; c) J. Pyun, K. Matyjaszewski, Macro-molecules 2000, 33, 217220; d) Y. Tsujii, K. Ohno, S. Ya-mamoto, A. Goto, T. Fukuda, Adv. Polym. Sci. 2006, 197,

1 45; e) R. C. Advincula, W. J. Brittain, K. C. Baster, J.Ruhe, Polymer Brushes, Wiley-VCH, Weinheim, 2004 ; f) J.Pyun, K. Matyjaszewski, J. Wu, G. M. Kim, S. B. Chun, P. T.Mather,Polymer2003, 44, 27392750.

[59] K. Matyjaszewski, S. G. Gaynor, Macromolecules 1997, 30,70427049.

[60] a) F. S. Bates, G. H. Fredrickson, Physics Today 1999, 52,

32 38; b) N. Hadjichristidis, H. Iatrou, M. Pitsikalis, J.Mays, Prog. Polym. Sci. 2006, 31, 10681132; c) N. Hadji-christidis, M. Pitsikalis, S. Pispas, H. Iatrou, Chem. Rev.

2001, 101, 3747 3792; d) S. Foerster, T. Plantemberg,Angew. Chem. 2002, 114, 712739; Angew. Chem. Int. Ed.2002, 41, 688 714.




14/15

[61] a) N. A. Lynd, A. J. Meuler, M. A. Hillmyer, Prog. Polym.Sci. 2008, 33, 875893; b) L. Leibler, H. Benoit, Polymer1981, 22, 195 201; c) A.-V. Ruzette, S. Tence-Girault, L.Leibler, F. Chauvin, D. Bertin, O. Guerret, P. Gerard, Mac-romolecules 2006, 39, 58045814; d) L. Leibler, Prog.Polym. Sci. 2005, 30, 898914; e) L. Leibler, H. Orland,J. C. Wheeler, J. Chem. Phys. 1983, 79, 3550 3557; f) L. Lei-

bler, Makromol. Chem. Macromol. Symp. 1988, 16, 1 17;g) L. Leibler, Macromolecules1980, 13, 16021617.[62] J. Listak, W. Jakubowski, L. Mueller, A. Plichta, K. Matyjas-

zewski, M. R. Bockstaller, Macromolecules 2008, 41, 59195927.

[63] a) T. Kowalewski, R. D. McCullough, K. Matyjaszewski,Eur. Phys. J. E: Soft Matter2003, 10 , 516; b) L. A. McCul-lough, B. Dufour, K. Matyjaszewski, Macromolecules 2009,42, 81298137; c) L. A. McCullough, B. Dufour, C. Tang, R.Zhang, T. Kowalewski, K. Matyjaszewski, Macromolecules2007, 40, 77457747; d) L. A. McCullough, K. Matyjaszew-ski, Mol. Cryst. Liq. Cryst. 2010, 521, 155.

[64] P. D. Hustad,Science2009, 325, 704 707.[65] a) C. Tang, A. Tracz, M. Kruk, R. Zhang, D.-M. Smilgies, K.

Matyjaszewski, T. Kowalewski, J. Am. Chem. Soc. 2005, 127,

69186919; b) C. Tang, W. Wu, D.-M. Smilgies, K. Matyjas-zewski, T. Kowalewski, J. Am. Chem. Soc. 2011, 133,1180211809.

[66] K. Matyjaszewski, J. Spanswick, Materials Today 2005, 8,2633.

[67] a) N. Hasegawa, Y. Shimizu, Y. Nakagawa, USPTO,US6784240, 2004 ; b) S. Balk, G. Loehden, H. Kautz, C.Troemer, M. Maerz, L. Zander, J. Lueckert, J. Klein, T. Mo-eller, WIPO, WO 2009144082, 2009-EP54364, 2009 ; c) J.Kotani, Y. Nakagawa, PCT Int. Appl., WO2004011552,2004011552, 2004; d) S. Ono, Y. Nakagawa, PCT Int. Appl.,WO2006075712, 2006075712,2006.

[68] H. Camenzind, P. Dubs, P. Hanggi, R. Martin, A. Muhle-bach, F. Rime, USPTO, US 7615522, 2009.

[69] a) S. Roos, B. Eisenberg, M. Mueller, PCT Int. Appl.,WO0140317, 0140317, 2001; b) T. Stohr, M. Muller, B. Ei-senberg, H. Becker, A. Muller, PCT Int. Appl., WO/2007/025837, PCT/EP2006/065060, 2007.

[70] N. Fujita, Y. Shimizu, N. Hasegawa, Y. Nakagawa, PCT Int.Appl., WO0190224, 0190224, 2001.

[71] R. Knischka, E. Eckstein, C. Auschra, A. Matsumoto, PCTInt. Appl., WO2006074969, 2006074969,2006.

[72] C. Auschra, E. Eckstein, M.-O. Zink, A. Muehlebach, PCTInt. Appl., WO0346029, 0346029,2003.

[73] a) S. Coca, G. J. McCollum, J. B. ODwyer, B. E. Wood-worth, PCT Int. Appl., WO0144388, 0144388, 2001; b) C.Auschra, E. Eckstein, A. Muhlebach, M.-O. Zink, F. Rime,Progress in Organic Coatings 2002, 45, 8393; c) B. E.Woodworth, S. Coca, J. B. ODwyer, PCT Int. Appl.,

WO0144376, 0144376,2001.[74] a) B. Gobelt, O. Jrgen, WO/2008/043529, 2008 ; b) A.

Muehlebach, F. Rime, C. Auschra, E. Eckstein, PCT Int.Appl., WO 2001/0151534, 0151534, 2001; c) D. White, S.Coca, J. B. ODwyer, USPTO, US6642301, 2003; d) T.Ohata, N. Endou, H. Okada, A. Kawaguchi, H. Tanooka, Y.Ijima, N. Sako, WIPO, WO/2008/156148, 2008; e) C. Bur-guiere, S. Pascual, B. Coutin, A. Polton, M. Tardi, B. Char-leux, K. Matyjaszewski, J.-P. Vairon, Macromol. Symp. 2000,150, 3944; f) A. M. Heming, P. J. Mulqueen, H. B. Scher,I. M. Shirley, PCT Int. Appl., WO 20020100525, 0100525,2002 ; g) J. Xia, T. Johnson, S. G. Gaynor, K. Matyjaszewski,J. DeSimone, Macromolecules 1999, 32, 48024805; h) W.

Jakubowski, J.-F. Lutz, S. Slomkowski, K. Matyjaszewski, J.Polym. Sci. Part A: Polym. Chem. 2005, 43, 14981510;i) W. Jakubowski, K. Matyjaszewski, Macromol. Symp. 2006,240, 213 223; j) S. Slomkowski, M. Gadzinowski, S. Sos-nowski, C. De Vita, A. Pucci, F. Ciardelli, W. Jakubowski,K. Matyjaszewski, Macromol. Symp. 2005, 226, 239252;k) H. Coelfen, Macromol. Rapid Commun. 2001, 22, 219

252.[75] a) C. Auschra, E. Eckstein, A. Muhlebach, M.-O. Zink, F.Rimo, Athens Conference on Coatings: Science and Technol-ogy, Proceedings, 27th, Athens, Greece, July 26, 2001, 2001,3347; b) D. Kuppert, T. Veit, P. Favresse, B. A. Vom Bruch,W. Muller, M. Loebbus, WIPO, WO/2010/018044, 2010.

[76] L. Bombalski, H. Dong, J. Listak, K. Matyjaszewski, M. R.Bockstaller,Adv. Mater. 2007,19, 44864490.

[77] E. G. Koulouri, J. K. Kallitsis, G. Hadziioannou,Macromole-cules1999, 32, 62426248.

[78] a) T. Matsugi, J. Saito, N. Kawahara, S. Matsuo, H. Kaneko,N. Kashiwa, M. Kobayashi, A. Takahara, Polym. J. 2009, 41,547554; b) N. Kawahara, J. Saito, S. Matsuo, H. Kaneko,T. Matsuki, N. Kashiwa, Jpn. Kokai Tokkyo Koho, Applica-tion: JP 2009292911, 2008146951, 2009 ; c) H. Kaneko, J.

Saito, N. Kawahara, S. Matsuo, T. Matsugi, N. Kashiwa,ACS Symp. Ser.2009, 1023, 357 371.

[79] a) P. McCarthy, M. Chattopadhyay, G. L. Millhauser, N. V.Tsarevsky, L. Bombalski, K. Matyjaszewski, D. Shimmin, N.Avdalovic, C. Pohl, Anal. Biochem. 2007, 366, 1 8; b) P.McCarthy, N. V. Tsarevsky, L. Bombalski, K. Matyjaszewski,C. Pohl, ACS Symp. Ser. 2006, 944, 252 268.

[80] K. Suzuki, A. Uno, M. Tamura, Y. Kubo, M. Horibe, S. Ka-bashima, M. Sato, WO 2008/081832, 2008.

[81] W. Jakubowski, J. Spanswick, L. Mueller, K. Matyjaszewski,PCT Int. Appl., WO 2007075817, 2007075817, 2007.

[82] K. Min, H. Gao, K. Matyjaszewski,J. Am. Chem. Soc. 2006,128, 1052110526.

[83] K. Matyjaszewski, J. Spanswick, in Thermoplastic Elasto-

mers, 3rd ed., Hanser Publishers, Munich,2004.[84] a) B. Dufour, C. Tang, K. Koynov, Y. Zhang, T. Pakula, K.Matyjaszewski, Macromolecules 2008, 41, 2451 2458; b) B.Dufour, K. Koynov, T. Pakula, K. Matyjaszewski, Macro-mol. Chem. Phys. 2008,209, 16861693.

[85] D. Neugebauer, Y. Zhang, T. Pakula, S. S. Sheiko, K. Maty-jaszewski, Macromolecules 2003, 36, 67466755.

[86] a) T. Pakula, K. Matyjaszewski, PCT Int. Appl., WO2004014963, 2004014963, 2004 ; b) T. Pakula, Y. Zhang, K.Matyjaszewski, H.-i. Lee, H. Boerner, S. Qin, G. C. Berry,Polymer 2006, 47, 71987206; c) Y. Zhang, N. Costantini,M. Mierzwa, T. Pakula, D. Neugebauer, K. Matyjaszewski,Polymer2004, 45, 63336339.

[87] a) K. Matyjaszewski, H. Dong, W. Jakubowski, J. Pietrasik,A. Kusumo, Langmuir 2007, 23, 45284531; b) M. Ejaz, S.

Yamamoto, K. Ohno, Y. Tsujii, T. Fukuda, Macromolecules1998, 31, 59345936.

[88] S. Yamamoto, M. Ejaz, Y. Tsujii, T. Fukuda, Macromole-cules2000, 33, 56085612.

[89] J. G. Linhardt, K. J. F, USPTO, US Application20090173044, 2009.

[90] W. Jaeger, J. Bohrisch, A. Laschewsky, Prog. Polym. Sci.2010, 35, 511 577.

[91] a) J. Huang, H. Murata, R. R. Koepsel, A. J. Russell, K. Ma-tyjaszewski, Biomacromolecules 2007, 8, 13961399; b) L.Li, Z. Ke, G. Yan, J. Wu, Polym. Int. 2008, 57, 12751280;c) K. Glinel, A. M. Jonas, T. Jouenne, J. Leprince, L. Galas,W. T. S. Huck, Bioconjugate Chem. 2009, 20, 7177; d) S. B.




15/15

Lee, R. R. Koepsel, S. W. Morley, K. Matyjaszewski, Y. Sun,A. J. Russell, Biomacromolecules 2004, 5, 877 882; e) J.Lindqvist, E. Malmstroem, J. App. Polym. Sci. 2006, 100,41554162; f) H. Dong, P. Ye, M. Zhong, J. Pietrasik, R.Drumright, K. Matyjaszewski, Langmuir 2010, 26, 1556715573.

[92] S. Lenoir, C. Pagnoulle, C. Detrembleur, M. Galleni, R.

Jerome, J. Polym. Sci. Part A: Polym. Chem. 2006, 44,12141224.[93] S. Lenoir, C. Pagnoulle, M. Galleni, P. Compere, R. Jerome,

C. Detrembleur,Biomacromolecules2006, 7, 22912296.[94] T. Ravikumar, H. Murata, R. R. Koepsel, A. J. Russell,Bio-

macromolecules2006, 7, 27622769.[95] a) E. J. Lobb, I. Ma, N. C. Billingham, S. P. Armes, A. L.

Lewis, J. Am. Chem. Soc. 2001, 123, 7913 7914; b) M.-C.Jones, M. Ranger, J.-C. Leroux, Bioconjugate Chem. 2003,14, 774781; c) J. K. Oh, D. J. Siegwart, H.-i. Lee, G. Sher-wood, L. Peteanu, J. O. Hollinger, K. Kataoka, K. Matyjas-zewski, J. Am. Chem. Soc. 2007, 129, 5939 5945; d) S. M.Ryan, G. Mantovani, X. Wang, D. M. Haddleton, D. J. Bray-den, Expert Opin. Drug Delivery 2008, 5, 371 383; e) H.Dong, V. Mantha, K. Matyjaszewski, Chem. Mater. 2009, 21,

39653972; f) J. K. Oh, S. A. Bencherif, K. Matyjaszewski,Polymer 2009, 50, 44074423; g) D. J. Siegwart, A. Sriniva-san, S. A. Bencherif, A. Karunanidhi, J. K. Oh, S. Vaidya, R.Jin, J. O. Hollinger, K. Matyjaszewski, Biomacromolecules2009, 10, 2300 2309; h) P. L. Golas, K. Matyjaszewski,

Chem. Soc. Rev. 2010, 39, 13381354; i) J. A. Yoon, S. A.Bencherif, B. Aksak, E. K. Kim, T. Kowalewski, J. K. Oh, K.Matyjaszewski, Chem. Asian J. 2011, 6, 128 136; j) J. A.Johnson, N. J. Turro, J. T. Koberstein, J. E. Mark, Prog.Polym. Sci.2010,35, 332 337.

[96] a) R. E. Richard, M. Schwarz, S. Ranade, A. K. Chan, K.Matyjaszewski, B. Sumerlin, Biomacromolecules 2005, 6,

34103418; b) R. E. Richard, M. Schwarz, S. Ranade, A. K.Chan, K. Matyjaszewski, B. Sumerlin, ACS Symp. Ser. 2006,944, 234 251.

[97] J. K. Oh, D. J. Siegwart, K. Matyjaszewski, Biomacromole-cules2007, 8, 33263331.

[98] H. Y. Cho, H. Gao, A. Srinivasan, J. Hong, S. A. Bencherif,D. J. Siegwart, H.-j. Paik, J. O. Hollinger, K. Matyjaszewski,Biomacromolecules2010,11, 21992203.

[99] a) J.-F. Lutz, H. G. Boerner, Prog. Polym. Sci. 2008, 33, 1 39; b) J. Nicolas, G. Mantovani, D. M. Haddleton, Macro-mol. Rapid Commun. 2007, 28, 10831111; c) K. L. Hered-ia, D. Bontempo, T. Ly, J. T. Byers, S. Halstenberg, H. D.Maynard, J. Am. Chem. Soc. 2005, 127, 1695516960;d) B. S. Lele, H. Murata, K. Matyjaszewski, A. J. Russell,Biomacromolecules2005,6, 33803387.

Received: September 3, 2011Accepted: October 21, 2011

Published online: April 16, 2012



atom transfer radical polymerization from mechanisms to applications 2012 israel journal of...

Documents