Combination Of Atom Transfer Radical Polymerization Research Articles

Synthesis of binary-patterned brushes by combining atom transfer radical polymerization and ring-opening polymerization

Abstract This paper report the synthesis of binary-patterned brushes, combining two distinctive surface initiated-polymerizations (SIP) on the basis of different propagating species: the SI Ring Opening Polymerization (ROP) of L-Lactide (LLA) and SI atom transfer radical polymerization (ATRP) of N,N’-dimethylaminoethyl methacrylate (DMAEMA) on gold surface. First of all, a careful study of surfaceinitiated ROP of L-Lactide from hydroxyl end-group of thiol monolayer on gold surface as catalyzed by metal-free catalyst was carried out. The PLLA brushes synthesis was evaluated using two types of thiol monolayer and revealed the influence of ROP initiator chain length on the final thickness of the PLLA film. Combining the soft lithographic technique, microcontact printing, and the liquid phase deposition, the deposition onto specific micro-domains of both initiators was performed. The growth of PDMAEMA brushes and PLLA brushes was conducted by successive ATRP and ROP.

Synthesis of binary-patterned brushes by combining atom transfer radical polymerization and ring-opening polymerization

This paper report the synthesis of binary-patterned brushes, combining two distinctive surface initiated-polymerizations (SIP) on the basis of different propagating species: the SI Ring Opening Polymerization (ROP) of L-Lactide (LLA) and SI atom transfer radical polymerization (ATRP) of N,N’-dimethylaminoethyl methacrylate (DMAEMA) on gold surface. First of all, a careful study of surfaceinitiated ROP of L-Lactide from hydroxyl end-group of thiol monolayer on gold surface as catalyzed by metal-free catalyst was carried out. The PLLA brushes synthesis was evaluated using two types of thiol monolayer and revealed the influence of ROP initiator chain length on the final thickness of the PLLA film. Combining the soft lithographic technique, microcontact printing, and the liquid phase deposition, the deposition onto specific micro-domains of both initiators was performed. The growth of PDMAEMA brushes and PLLA brushes was conducted by successive ATRP and ROP.

Synthesis and fluorescence properties of star-shaped polymers carrying two fluorescent moieties

A well-defined fluorescent star-shaped polymer containing two different fluorescent functionalities one in the main chain and another in the end group was designed and synthesized by combining atom transfer radical polymerization (ATRP) and azide-alkyne click reaction. The star polymer with four arms was prepared from copolymerization of methyl methacrylate and 4-(2-(9-anthryl))-vinyl-styrene using ATRP. Subsequently the end group was modified with another fluorescent moiety by click coupling. The structure of all the intermediate and final products was established through NMR spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, UV−visible spectroscopy and fluorescence spectroscopy. The novel hybrid polymer exhibits an attractive high fluorescence at 494 nm and over a broad range which was a combination of both the fluorescence moieties. © 2013 Society of Chemical Industry

Linear-, Cyclic-, and Multiblock Amphiphilic Polyelectrolytes as Surfactants in Emulsion Polymerization: Role of Topological Structure

Combining atom transfer radical polymerization (ATRP) and “click” chemistry, a set of well-defined amphiphilic block copolymers poly(n-butyl acrylate)-b-poly(acrylic acid) (PnBA20-PAA85) with a similar chemical component, but different topological structures, i.e., linear-, cyclic-, and multiblock structures, were successfully prepared, characterized (size exclusion chromatography (SEC), FT-IR and 1H NMR), and used as surfactants in emulsion polymerization. Our further transmission electron microscopy (TEM) and laser light scattering (LLS) characterization of the resultant latex particles demonstrates all the surfactants with different topologies can effectively stabilize the latex particles but no significant difference among the solids contents was observed. Moreover, we have, for the first time, experimentally established the quantitative relation between the final number of latex particles (Np) and the concentration of polymeric surfactant with different topologies (C), i.e., Np = kCα, and the order of our measured exponent α is as follows: αmulti(1.10) > αlinear(0.81) ≥ αcyclic(0.73), indicating cyclic surfactant molecules behave more like small-molecule surfactants attributed to its strongest unimers extraction and diffusion ability; in contrast, multiblock surfactant molecules can act as seeds to directly nucleate to create latex particles. In addition, Np,multi > Np,linear ≥ Np,cyclic at higher concentration, and Np,linear > Np,cyclic ≥ Np,multi at lower concentration was observed. Similar results (αmulti(1.02) > αlinear(0.65) ≥ αcyclic(0.58)) were also observed when polystyrene-b-poly(acrylic acid) (PS9–PAA60) copolymers were used as surfactants. Further aqueous SEC characterization shows the broad size distribution of our micellar solution has no effect on obtaining narrowly distributed latex particles. Finally, interfacial tension measurement of the micellar solution indicates, compared to multiblock structure, the rate of adsorption at a hydrophobic interface is much faster for linear and cyclic-block structures, agreeing with our observed order of exponent α.

Surface-functionalizable membranes of polycaprolactone-click-hyperbranched polyglycerol copolymers from combined atom transfer radical polymerization, ring-opening polymerization and click chemistry.

Hyperbranched polyglycerols containing terminal alkyne and alkyl bromide groups (CH[triple bond, length as m-dash]C-HPG-Br) were first synthesized via propargyl alcohol-initiated ring-opening polymerization (ROP) of glycidol, followed by reaction of 2-bromoisobutyryl bromide (BIBB) with the hydroxyl groups to introduce the atom transfer radical polymerization (ATRP) initiators on HPG. Hydrophobic azido-terminated poly(ε-caprolactone) (PCL-N3), prepared a priori via 2-azidoethanol-initiated ROP of ε-caprolactone, was then coupled to the CH[triple bond, length as m-dash]C-HPG-Br polymer through a Cu(i)-catalyzed alkyne-azide click reaction. The resultant linear-hyperbranched PCL-click-HPG copolymers were cast by phase inversion in an aqueous medium into microporous membranes of well-defined and uniform pores. Not only could the HPG contents in the PCL-click-HPG copolymers be used to control the pore size and porosity of the resulting membranes, but also the alkyl halide chain-ends of HPG allowed the subsequent functionalization of membrane and pore surfaces. The PCL-click-HPG-b-PMPC membrane was prepared via surface-initiated ATRP of zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) from the PCL-click-HPG membrane and pore surfaces. The PCL-click-HPG-b-PMPC membranes exhibit good antifouling and antibacterial adhesion properties with negligible cytotoxicity effects, making the membranes potentially useful for biomaterials and biomedical applications.

Divergent synthesis of dendrimer-like pH-responsive macromolecules through a combination of ATRP and ROP for controlled release of anti-cancer drug.

This work is focused on the synthesis and controlled drug release behavior of 8-arm and 12-arm amphiphilic pH-responsive dendrimer-like block copolymers. To study the role of architecture and the number of arms at the critical micelle concentration (CMC) value, differential scanning calorimetry (DSC), micelle size and in vitro controlled release of drug, we investigated a series of 8-arm and 12-arm block copolymers. The poly(acrylic acid) (PAA)-carrying dendrimer-like block copolymers were synthesized in two main steps. First, a second-generation dendrimer-like poly(ε-caprolactone) (PCL) was obtained by ring-opening polymerization (ROP) of ε-caprolactone (CL) from a bis and tris-hydroxylated core. For this goal, a conventional selective AB2-type branching agent for the PCL chain ends was designed: the latter includes a carboxyl (A) group for its attachment to the PCL arm ends and two geminal hydroxyls (B2) for the reiteration of the PCL growth as second generation using ROP. Subsequently, the hydroxyl-end groups quantitatively converted into bromoester groups as atom transfer radical polymerization (ATRP) initiating sites. The second step is the ATRP which thus served to grow poly(tBA) chains. After the hydrolysis of the t-butyl ester groups, amphiphilic, pH-responsive dendrimer-like block copolymers were obtained. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) demonstrated that the micelles exhibit a spherical shape with a size range of 43-64 nm in diameter. As a model drug, quercetin was loaded into the obtained 2G3(PAA)8 and 3G3(PAA)12 micelles via a dialysis method for in vitro release studies and their response to pH variation was investigated. The in vitro cytotoxicity evaluation of the polymers clearly showed that both compounds are safe in a wide range of concentrations (several times above the CMC value).

Atom transfer radical polymerization of hydrophilic monomers and its applications

Atom transfer radical polymerization (ATRP) has become one of the most widely used living radical polymerization techniques for preparation of polymers with pre-designed compositions, topologies and functionalities. Hydrophilic (co)polymers are broadly used in various fields, such as hybrid materials, surface modification and delivery carriers in biomedical areas because of their diverse functionalities and ideal characters, including their non-toxicity, biocompatibility and environmentally friendly nature. Polymerization of hydrophilic monomers by ATRP provides polymers with more colorful structures, as well as novel properties and extends the application scope of hydrophilic polymers due to its facile operation and commercially available catalysts, ligands and initiators of the methodology. This review focuses on ATRP of hydrophilic monomers, as well as its application as detailed in five aspects: (1) basic understanding of the ATRP mechanism and polymerization kinetics of hydrophilic monomers; (2) polymerization media for hydrophilic monomers; (3) topologies of polymers based on hydrophilic monomers; (4) polymerization by combination of ATRP with other techniques, and (5) applications of polymerization of hydrophilic monomers.

Intrachain Folding and Interchain Association of Hyperbranched Chains with Long Uniform Subchains Made of Amphiphilic Diblock Copolymers

Combining atom transfer radical polymerization and copper-catalyzed azide–alkyne “click” chemistry, hyperbranched copolymers with uniform poly(tert-butyl acrylate-b-styrene-b-tert-butyl acrylate) triblock copolymer subchains, denoted as hyper-(PtBA-PS-PtBA)n, were successfully prepared and characterized by size exclusion chromatography (SEC), FT-IR, and 1H NMR. Using laser light scattering, we first studied the intrachain contraction of ultralarge hyper-(PtBA36-PS55-PtBA36)600 chains in cyclohexane, a solvent selectively poor for PS at lower temperatures. We found that at temperatures lower than 34 °C each PS block collapses into a small globule that was stabilized by its three neighboring PtBA blocks with no intrachain or interchain association in a dilute solution. Further, after hydrolyzing those tert-butyl (tBA) moieties into acrylic acids (AA), we comparatively studied the interchain association of linear triblock PAA23-PS14-PAA23 and its resultant hyper-(PAA23-PS14-PAA23)n with different overall mol...

Photoresponsive Azopolyester–PMMA Block Copolymers Obtained by Combination of ATRP, Polycondensation, and “Click” Chemistry

AbstractNovel azobenzene‐containing block copolymers (BCs) with a polyester block bearing azobenzene moieties in the side chain and a poly (methyl methacrylate) (PMMA) block have been synthesized by the combination of atom transfer radical polymerization (ATRP), polycondensation, and “click” chemistry. Two azide‐terminated polyesters with different molecular weight (obtained by polycondensation) were coupled to an alkyne‐functionalized PMMA (obtained by ATRP). Blends of the BC with the highest azo content (wt%) and an azopolyester homopolymer were also prepared. All these compounds were investigated by polarized light optical microscopy (POM), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Polarized light‐induced anisotropy was studied by birefringence and dichroism measurements.

Microfluidics assisted fabrication of microspheres by poly(2–hydroxyethyl methacrylate)-block-poly(l-histidine) hybrid materials and their utilization as potential drug encapsulants

A new series of synthetic polymer bioconjugate hybrid materials consisting of poly(2-hydroxyethyl meth- acrylate)(p(HEMA))as a synthetic polymer block and poly(L-histidine) (p(His)) as a polypeptide block were syn- thesized by combining atom transfer radical polymerization of HEMA with ring opening polymerization of benzyl- N-carboxy-L-histidine anhydride. The resulting biocompat- ible p(HEMA)25-b-p(His)n (n = 15, 25, 35, and 45) hybrid polymers were investigated for their use as pH-sensitive drug delivery system. Highly uniform microspheres were fabricated by using the microfluidics assisted self-assembly of these block polymers and utilized them as carriers for a chemotherapeutic agent doxorubicin and a beta-lactam antibiotic ampicillin for the evaluation of the drug-loading and release behaviors according to pH, demonstrating the release is sensitive to pH. The capability of the new p(HEMA)-b-p(His) hybrid materials to self-assemble in microenvironments and to effectively encapsulate drug molecules serves as suitable carriers for the delivery of drug molecules with varying physiochemical properties.

Synthesis and pyrolysis of ABC type miktoarm star copolymers with polystyrene, poly(lactic acid) and poly(ethylene glycol) arms

An ABC type miktoarm star copolymer possessing polystyrene (PS), poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) arms was synthesized by combining Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP) with two click chemistries, namely thiol–ene and copper catalyzed azide–alkyne cycloaddition (CuAAC). For this purpose, a core 1-(allyloxy)-3-azidopropan-2-ol with allyl and azide functionalities was synthesized in two steps. Then, clickable polymers, polystyrene with thiol functionality (PS–SH) and poly(ethylene glycol) with alkyne functionality (PEG–acetylene) were independently prepared. As the first step of the grafting onto process, PS–SH was thiol–ene clicked onto the core to yield PS–N3–OH. The second arm was then incorporated onto the core by the Ring Opening Polymerization (ROP) of l-(−)-Lactide (LA) using as PS–N3–OH initiator and tin(II) 2-ethylhexanoate as catalyst. Finally, alkyne–PEG–acetylene was bonded to the resulting PLA–PS–N3 using CuAAC click reaction. All intermediates, related polymers at different stages and final PS–PLA–PEG miktoarm star copolymer were characterized by 1H NMR, FT-IR, SEC and DP-MS analyses. Direct pyrolysis mass spectrometry, (DP-MS) analyses of PS–PLA–PEG and all intermediate polymers indicated that the decomposition of PS and PEG chains occurred almost independently, following the degradation mechanisms of the corresponding homopolymers. On the other hand, during the pyrolysis of PS–PLA–PEG, elimination of H2O during the decomposition of PEG chains at the early stages of pyrolysis caused hydrolysis of PLA chains and increased the yields of CO2, CO and units involving unsaturation and/or crosslinked structure.

Surface‐Initiated Controlled Radical Polymerization in Ordered Mesoporous Silicas

AbstractRecent advances in the synthesis of well‐defined high‐surface‐area mesoporous silica/polymer composites via surface‐initiated polymerization (“grafting from” method) and via attachment of preformed polymer chains (“grafting to” method) to surfaces of ordered mesoporous silicas (OMSs) are reviewed in the context of related research areas. Prior work on polymerizations in nanoscale confinements of OMSs is outlined and surface‐initiated polymerization in disordered mesoporous silicas is briefly discussed. Early work on the surface‐initiated radical polymerization initiated from OMS surface is reviewed and recent work involving OMS supports with large mesopores is discussed to illustrate the ability to form well‐defined polymer brushes in nanopores using atom transfer radical polymerization (ATRP). The synthesis of polymer brushes in mesopores through the combination of ATRP or other polymerizations and the “click” chemistry is also outlined.

Preparation of stimuli responsive polycaprolactone membranes of controllable porous morphology via combined atom transfer radical polymerization, ring-opening polymerization and thiol–yne click chemistry

Linear di-block copolymers of poly(N-isopropylacrylamide) (PNIPAM) with a center disulfide linkage were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAM) using a bifunctional disulfide-based initiator. The center disulfide bond was cleaved by reduction with excess DL-1,4-dithiothreitol (DTT) to form thiols. The resulting thiol-terminated PNIPAM chains were conjugated to alkyne-terminated poly(e-caprolactone) (PCL) via UV-initiated thiol–yne click reaction to produce the PCL-click-PNIPAM AB2-type copolymers. The PCL-click-PNIPAM copolymers were cast by phase inversion in an aqueous medium into microporous membranes of well-defined and uniform pores. The PNIPAM content in the PCL-click-PNIPAM copolymers could be used to control the pore size and porosity of the resulting membranes. The PCL-click-PNIPAM-b-PNaSS membrane was prepared via surface-initiated ATRP of sodium 4-styrenesulfonate (NaSS) from the PCL-click-PNIPAM membrane and pore surfaces. The temperature and electrolyte responsive characteristics of the PCL-click-PNIPAM and PCL-click-PNIPAM-b-PNaSS membranes were illustrated in the swelling behavior and controlled glucose transport through the membranes. These stimuli responsive membranes with controllable morphology and low cytotoxicity have potential applications in biomedical engineering, drug delivery and tissue engineering.

Biocompatible Poly(2‐hydroxyethyl methacrylate)‐b‐poly(L‐histidine) Hybrid Materials for pH‐Sensitive Intracellular Anticancer Drug Delivery

AbstractA series of synthetic polymer bioconjugate hybrid materials consisting of poly(2‐hydroxyethyl methacrylate) (p(HEMA)) and poly(l‐histidine) (p(His)) are synthesized by combining atom transfer radical polymerization of HEMA with ring opening polymerization of benzyl‐N‐carboxy‐L‐histidine anhydride. The resulting biocompatible and membranolytic p(HEMA)25‐b‐p(His)n (n = 15, 25, 35, and 45) polymers are investigated for their use as pH‐sensitive drug‐carrier for tumor targeting. Doxorubicin (Dox) is encapsulated in nanosized micelles fabricated by a self‐assembly process and delivered under different pH conditions. Micelle size is characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM) observations. Dox release is investigated according to pH, demonstrating the release is sensitive to pH. Antitumor activity of the released Dox is assessed using the HCT 116 human colon carcinoma cell line. Dox released from the p(HEMA)‐b‐p(His) micelles remains biologically active and has the dose‐dependent capability to kill cancer cells at acidic pH. The p(HEMA)‐b‐p(His) hybrid materials are capable of self‐assembling into nanomicelles and effectively encapsulating the chemotherapeutic agent Dox, which allows them to serve as suitable carriers of drug molecules for tumor targeting.

Synthesis, properties, and electrical memory characteristics of new diblock copolymers of polystyrene-block-poly(styrene-pyrene)

In this study, we report the synthesis, properties, and electrical memory characteristics of new diblock copolymers, polystyrene-block-poly(styrene-pyrene) (PS-b-P(St-Py)), prepared by combining atom transfer radical polymerization and Suzuki coupling reaction. The effects of the St–Py block chain length on the electronic energy level, photophysical properties, and memory characteristics were explored. The PS42-b-P(St-Py)108 and PS66-b-P(St-Py)67 devices exhibited a dynamic random access memory characteristics with different turn-on threshold voltages of −2.7 and −3.1 V, respectively. Moreover, these memory devices showed a high ON/OFF current ratio of 109 and were electrically stable for at least 104 s in both ON and OFF states. However, the PS113-b-P(St-Py)45-based device displayed an insulating state in a low current variation of 10−12 to 10−14 A, which had a short St–Py block length. The mechanism of the switching behavior was explained by the charge hopping conduction between the pyrene units with coexisting charge-trapping environment. The volatility of the memory effect was depended on the ability of charge trapping/back transferring of trapped charge. The present study suggested that the electrical memory characteristics could be efficiently tuned through the block ratio between insulating segment and pendant-conjugated segment of the diblock polymers.

Synthesis and characterization of fluorescent perylene bisimide-containing glycopolymers for Escherichia coli conjugation and cell imaging

Fluorescent glycopolymers were prepared via combined atom transfer radical polymerization (ATRP) and ‘Click Chemistry’ in one-pot synthesis, in the presence of 2-azidoethyl methacrylate (AzEMA), 2-propynyl α- d-mannopyranoside, N, N′-bis{2-[2-[(2-bromo-2-methylpropanoyl)oxy]ethoxy]ethyl}perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI-Br), copper (I) bromide catalyst and pentamethyldiethylenetriamine (PMDETA) ligand. Simultaneous ATRP and ‘Click Chemistry’ is an attractive method for the synthesis of functional glycopolymers as the reaction conditions are compatible with ATRP of an azide monomer, as long as an alkynyl-functionalized carbohydrate is available for click coupling reaction. The fluorescent glycopolymers were characterized by 1H NMR, FT-IR, UV–visible absorption, fluorescence and X-ray photoelectron spectroscopies, as well as by gel permeation chromatography. Incubation of Escherichia coli (E. coli DH5 α) with the fluorescent glycopolymers yielded green fluorescent bacterial clusters. The low cytotoxicity level of the fluorescent glycopolymers was revealed by incubation with 3T3 fibroblasts, macrophages and KB cells in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays in vitro. Subsequently, the water-soluble, biocompatible and fluorescent glycopolymers were used as effective fluorescent cell labeling agents.

Construction of Polymer–Protein Bioconjugates with Varying Chain Topologies: Polymer Molecular Weight and Steric Hindrance Effects

We report on the fabrication of well-defined polymer-protein bioconjugates with varying chain architectures, including star polymers, star block copolymers, and heteroarm star copolymers through the specific noncovalent interaction between avidin and biotinylated synthetic polymer precursors. Homopolymer and diblock precursors site-specifically labeled with a single biotin moiety at the chain terminal, chain middle, or diblock junction point were synthesized by a combination of atom-transfer radical polymerization (ATRP) and click reactions. By taking advantage of molecular recognition between avidin and biotin moieties, supramolecular star polymers, star block copolymers, and heteroarm star copolymers were successfully fabricated. This specific binding process was also assessed by using the diffraction optic technology (DOT) technique. We further investigated the effects of polymer molecular weights, location of biotin functionality within the polymer chain, and polymer chain conformations, that is, steric hindrance effects, on the binding numbers of biotinylated polymer chains per avidin within the polymer-protein bioconjugates, which were determined by the standard avidin/2-(4-hydroxyazobenzene)benzoic acid (HABA) assay. The binding numbers vary in the range of 1.9-3.3, depending on the molecular weights, locations of biotin functionality within synthetic polymer precursors, and polymer chain conformations.

High-Performance Field-Effect Transistors Based on Polystyrene-b-Poly(3-hexylthiophene) Diblock Copolymers

Polystyrene-b-poly(3-hexylthiophene) (PS-b-P3HT) block copolymers with fixed PS block length have been synthesized by combined atom transfer radical polymerization (ATRP) and Grignard metathesis (GRIM) polymerization. The self-assembled structures of these diblock copolymer thin films based on PS-b-P3HT have been studied by TEM, SAED, GIXD, AFM, and additionally by first principles modeling and simulation. These block copolymers undergo microphase separation and form nanostructured spheres, lamellae, nanofibers, or nanoribbons in the films dictated by the molecular weight of the P3HT block. Within the diblock copolymer thin film, PS blocks segregate to form amorphous domains, and the covalently bonded conjugated P3HT blocks exist as highly ordered crystalline domains through intermolecular packing with their alkyl side chains aligned normal to the substrate while the thiophene rings align parallel to the substrate through π-π stacking. The conjugated PS-b-P3HT block copolymers exhibited significant improvements in organic field-effect transistor (OFET) performance and environmental stability as compared to P3HT homopolymers, with up to a factor of 2 increase in measured mobility (0.08 cm(2)/(V·s)) for the P4 (85 wt % P3HT). Overall, this work demonstrates that the high degree of molecular order induced by block copolymer phase separation can improve the transport properties and stability of conjugating polymers, which are critical for high-performance OFETs and other organic electronics.

Combining atom transfer radical polymerization and melt compounding for producing PMMA/clay nanocomposites

AbstractNanocomposites based on poly (methyl methacrylate) (PMMA) and 3 wt % of clay (montomorillonite) organomodified with alkylammonium cations bearing alkyl halide function (OCTANBriBBr‐CL) have been obtained by melt blending. The “nanohybrid” masterbatch approach, already used within other matrices, has also been tested to produce this type of material. Accordingly, highly filled (∼ 30 wt %) PMMA‐OCTANBriBBr‐CL nanohybrid has been synthesized by atom transfer radical polymerization (ATRP) of MMA as in situ initiated from the alkyl halide functions decorating the nanoclay surface. This nanohybrid, i.e., PMMA‐grafted organomodified clay, has been added as masterbatch and melt‐blended within commercial PMMA. A significantly better clay nanoplatelet dispersion of the samples prepared via the masterbatch process was evidenced by wide‐angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM). As a result, these exfoliated nanocomposites proved to be characterized by better thermal and mechanical properties than the more conventional physical blends, as evidenced by thermogravimetrical analysis (TGA) and dynamical mechanical analysis (DMTA), respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Polymeric nanomaterials from combined click chemistry and controlled radical polymerization

This review highlights recent research on the preparation of functional polymeric nanomaterials (nanoparticles, microcapsules, nanofibers, carbon nanotubes) by combined ‘click chemistry’ and controlled radical polymerization (CRP) techniques. In particular, it focuses primarily on combined atom transfer radical polymerization (ATRP), reversible addition-fragmentation transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and thiol-ene chemistry. These versatile techniques of polymer synthesis allow the preparation of functional polymeric nanomaterials with well-defined nanostructures and desired functionalities.