Controlled Atom Transfer Radical Polymerization Research Articles

Controlled ATRP Synthesis of Novel Linear-Dendritic Block Copolymers and Their Directed Self-Assembly in Breath Figure Arrays.

Herein, we report the formation and characterization of novel amphiphilic linear-dendritic block copolymers (LDBCs) composed of hydrophilic dendritic poly(ether-ester), PEE, blocks and hydrophobic linear poly(styrene), PSt. The LDBCs are synthesized via controlled atom transfer radical polymerization (ATRP) initiated by a PEE macroinitiator. The copolymers formed have narrow molecular mass distributions and are designated as LGn-PSt Mn, in which LG represents the PEE fragment, n denotes the generation of the dendron (n = 1–3), and Mn refers to the average molecular mass of the LDBC (Mn = 3.5–68 kDa). The obtained LDBCs are utilized to fabricate honeycomb films by a static “breath figure” (BF) technique. The copolymer composition strongly affects the film morphology. LDBCs bearing acetonide dendron end groups produce honeycomb films when the PEE fraction is lower than 20%. Pore uniformity increases as the PEE content decreases. For LDBCs with hydroxyl end groups, only the first generation LDBCs yield BF films, but with a significantly smaller pore size (0.23 μm vs. 1–2 μm, respectively). Although higher generation LDBCs with free hydroxyl end groups fail to generate honeycomb films by themselves, the use of a cosolvent or addition of homo PSt leads to BF films with a controllable pore size (3.7–0.42 μm), depending on the LDBC content. Palladium complexes within the two triazole groups in each of the dendron’s branching moieties can also fine-tune the morphology of the BF films.

Externally controlled atom transfer radical polymerization.

Spatial and temporal regulations of ATRP by external stimuli are presented. Various ATRP techniques, eATRP, photoATRP, and mechanoATRP, are controlled by electrical current, light, and mechanical forces, respectively. Conversely, ARGET and SARA ATRP are controlled by chemical reducing agents. ICAR ATRP is a thermally regulated process through decomposition of a radical initiator. The aim of this review is to highlight the use of external regulations in ATRP and to summarize the state-of-the-art and future perspectives, focusing on mechanistic aspects, synthetic procedures, preparation of polymers with complex architectures and functional materials, and their applications.

A novel strategy to construct highly conductive and stabilized anionic channels by fluorocarbon grafted polymers

In contrast to typical grafted anion exchange membranes (AEMs), a novel graft type AEM owning flurocarbon side chains and quaternized ammonium aromatic backbone was developed by a controlled atom transfer radical polymerization (ATRP) reaction. The experimental results revealed this kind of structure facilitated the formation of robust and long connective ion transport channels. Thus, the resulting AEM (IEC = 1.35mmol/g) exhibited a relatively high hydroxide conductivity of 44mS/cm, although its water uptake was below 30% (at 30°C). Simultaneously, this AEM also displayed fascinating mechanical strength and alkaline stability. A H2/O2 fuel cell test using incorporated fluorocarbon grafted AEMs yielded a peak power density of 85mW/cm2 at a current density of 150mA/cm2; this will be improved on development of a chemical compatible fluorine-based alkaline ionomer as ionic polymer binder in the electrodes' catalyst layers.

Synergic Effect between Nucleophilic Monomers and Cu(II) Metal–Organic Framework for Visible-Light-Triggered Controlled Photopolymerization

A Cu(II) metal-organic framework (MOF), Cu2(bdc)2(dabco), was found to be an efficient heterogeneous catalyst for controlled photopolymerization under visible light. The MOF, composed of photostimulable metal sites, was used to catalyze both photoninitiation as well as radical chain control and requires no external photoinitiator, dye sensitizer or ligand. A simple light trigger allowed the photoreduction of Cu(II) to the active Cu(I) state, enabling controlled atom transfer radical polymerization (ATRP). Compared to conventional ATRP with homogeneous catalysts, the ionic-bonded framework imparts high stability and robustness to the catalytic Cu(II) species. Therefore, the polymerization of vinylpyridines (2-vinylpyridine, 2VP and 4-vinylpyridine, 4VP), usually challenging by traditional polymerization strategies, was controlled up to high conversion (> 85 %) in 90 min, forming polymers with Ɖ < 1.3. Methacrylates such as 2-(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate were polymerize...

Enhancing Mechanically Induced ATRP by Promoting Interfacial Electron Transfer from Piezoelectric Nanoparticles to Cu Catalysts

A robust mechanically controlled atom transfer radical polymerization (mechano-ATRP) was developed by enhancing the interaction between piezoelectric nanoparticles and ATRP Cu catalysts. The interactions favor a mechano-induced electron transfer from the surface of the nanoparticles to the deactivator CuII/L complex under ultrasonic agitation, promoting the formation of the activator CuI/L complex, thereby increasing the rate of the polymerization. This mechano-ATRP was carried out with a low loading of zinc oxide nanoparticles, providing a polymer with high end-group fidelity, predetermined molecular weight, and low dispersity. Propagation of the polymer chains was switched on/off in response to the ultrasound. The effects of the nature of the nanoparticle, nanoparticle loading, and targeted degrees of polymerization were investigated to evaluate the mechanism of mechano-ATRP.

Cobalt and manganese complexes with redox-active ligands in polymerization of acrylonitrile and methyl methacrylate

The influence of bis[4,6-di-tert-butyl-N-(2,6-dimethylphenyl)-o-iminobenzosemiquinonato]cobalt(ii) and 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzosemiquinonato]-[4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-amidophenolate]manganese(iii) on polymerization of methyl methacrylate and acrylonitrile in the presence of azobisisobutyronitrile (as a traditional radical initiator) and alkyl halides (used for initiation of controlled atom transfer radical polymerization process) was studied. The effect of the nature of the activating agents (amines) and the temperature conditions on the overall polymerization rate of the indicated monomers, as well as molecular weight characteristics of the synthesized polymers, were analyzed. The optimal conditions for the synthesis of polyacrylonitrile and poly(methyl methacrylate) with a relatively narrow molecular weight distribution were selected.

Temporal Control in Mechanically Controlled Atom Transfer Radical Polymerization Using Low ppm of Cu Catalyst.

A mechanically controlled atom transfer radical polymerization (mechanoATRP) was successfully carried out in an ultrasound bath with low ppm of copper catalyst. The polymerization of methyl acrylate in the presence of CuBr2/tris(2-pyridylmethyl)amine catalyst using ultrasound as an external stimulus was temporally controlled by switching on-off ultrasound agitation. The first order kinetics was observed during ultrasonication. The experimental molecular weights agreed well with the theoretical values and displayed narrow molecular weight distribution. The effects of various types of piezoelectric BaTiO3 nanoparticles, loadings of nanoparticles, and targeted degrees of polymerization were studied.

Photoredox Catalysis for the Generation of Carbon Centered Radicals.

Radical chemistry has witnessed over the last decades important advances that have positioned it as a methodology of choice in synthetic chemistry. A number of great attributes such as specific reactivities, the knowledge of the kinetics of most elementary processes, the functional group tolerance, and the possibility to operate cascade sequences are clearly responsible for this craze. Nevertheless, at the end of the last century, radical chemistry appeared plagued by several hurdles to overcome such as the use of environmentally problematic mediators or the impossibility of scale up. While the concept of photocatalysis was firmly established in the coordination chemistry community, its diffusion in organic synthetic chemistry remained sporadic for decades until the end of the 2000s with the breakthrough merging of organocatalysis and photocatalysis by the MacMillan group and contemporary reports by the groups of Yoon and Stephenson. Since then, photoredox catalysis has enjoyed particularly active and intense developments. It is now the topic of a still increasing number of publications featuring various applications from asymmetric synthesis, total synthesis of natural products, and polymerization to process (flow) chemistry. In this Account, we survey our own efforts in this domain, focusing on the elaboration of new photocatalytic pathways that could lead to the efficient generation of C-centered functionalized alkyl and aryl radicals. Both reductive and oxidative manifolds are accessible through photoredox catalysis, which has guided us along these lines in our projects. Thus, we studied the photocatalytic reduction of onium salts such as sulfoniums and iodoniums for the production of the elusive aryl radical intermediates. Progressing to more relevant chemistry for synthesis, we examined the cleavage of C-O and the C-Br bonds for the generation of alkyl C-centered radicals. Activated epoxides could serve as valuable substrates of a photocatalyzed variant of the Nugent-RajanBabu-Gansäuer homolytic cleavage of epoxides. Using imidazole based carbamates, we could also devise the first photocatalyzed Barton-McCombie deoxygenation reaction. Finally, bromophenylacetate can be reduced using the [Au2(μ-dppm)2]Cl2 photocatalyst under UVA or visible-light. This was used for the initiation of the controlled atom transfer radical polymerization of methacrylates and acrylates in solution or laminate. Our next endeavors concerned the photocatalyzed oxidation of stabilized carbanions such as enolates of 1,3-dicarbonyl substrates, trifluoroborates, and more extensively bis-catecholato silicates. Because of their low oxidation potentials, the later have proved to be exquisite sources of radical entities, which can be engaged in diverse intermolecular reactions such as vinylation, alkynylation, and conjugate additions. The bis-catecholato silicates were also shown to behave as excellent partners of dual photoredox-nickel catalysis leading in an expeditious manner to libraries of cross coupling products.

Wohl‐Ziegler Bromination of Electrografted Films for Optimizing Atom Transfer Radical Polymerization

AbstractElectrografting of aryldiazonium compounds to conducting surfaces is extensively used to alter the surface properties. The highly reactive aryl radical is the actual grafting reagent, which on one hand is pertinent for the efficiency of the procedure but, on the other hand, in some cases is problematic by introducing unwanted side reactions. The electrografting of e.g. 4‐(bromomethyl)benzenediazonium is often carried out with the aim of creating a film that may serve as initiator for a controlled atom transfer radical polymerization. Unfortunately, this is difficult to accomplish because of bromine abstraction reactions occurring during the grafting process, which diminish the bromine content of the grafted layer significantly. Yet, this problem may be resolved by enriching the initiator film with bromine through a Wohl‐Ziegler bromination prior to the polymerization. An alternative pathway consisting of grafting 4‐methylbenzenediazonium followed by a bromination reaction to introduce bromine atoms at the benzylic position is shown to work equally well. Additionally, bromination of grafted benzyl alcohol groups have been explored. Finally, the repaired bromine films are used as a platform for atom transfer radical polymerization.

Intracellular plasmid DNA delivery by self-assembled nanoparticles of amphiphilic PHML-b-PLLA-b-PHML copolymers and the endocytosis pathway analysis.

This work presents a new series of polycationic nanoparticles of (l-)-lysine conjugated amphiphilic triblock copolymer poly(hydroxyletheyl methacrylate-L-lysine)-b-poly(L-lactide)-b-poly(hydroxyletheyl methacrylate-L-lysine)s (PHML-b-PLLA-b-PHML) as potent low cytotoxic vectors for intracellular plasmid DNA delivery. First, the triblock PHML-b-PLLA-b-PHML copolymers were prepared via a combination of metal-free controlled ring opening polymerization and successive atom transfer radical polymerization. Then the cationic PHML-b-PLLA-b-PHML nanoparticles were further prepared by solution self-assembly. The particle size, zeta potential and morphology of as-prepared PHML-b-PLLA-b-PHML nanoparticles were characterized by dynamic light scattering and atomic force microscopy, respectively. The plasmid DNA binding affinities and polyplex stabilities were separately explored by agarose gel retardation and DNase I degradation assays. Then invitro cytotoxicity and gene transfection efficiency of the PHML-b-PLLA-b-PHML nanoparticles vectors as well as relevant polyplex endocytosis pathway were investigated with H1299 cells. It was revealed that the PHML-b-PLLA-b-PHML nanoparticles exhibited low cytotoxicity, strong plasmid DNA binding affinity, high polyplex stability and efficient plasmid DNA transfection even under serum conditions (10% FBS). Moreover, the endocytosis analysis results disclosed that the PHML30-b-PLLA-b-PHML30 nanoparticle/plasmid DNA polyplexes were predominantly involved in lipid-raft-mediated endocytosis pathway, similar to that of SV40 virus-based vectors.

Synthesis of a complex additive based on stearyl methacrylate and vinyl acetate for environmentally clean diesel fuel

An additive based on stearyl methacrylate–vinyl acetate copolymer was synthesized by the method of controlled atom transfer radical polymerization. The additive simultaneously improves the low-temperature properties of hydrotreated diesel fuels and enhances their resistance to thermal oxidation to meet the European quality standards. Comparative analysis of the effect exerted on the characteristics of environmentally clean diesel fuel by the synthesized additive and Dodiflow commercial depressor additive was made, and the negative effect of the latter on the thermo oxidative stability of diesel fuel was revealed of the fuel to thermal oxidation was revealed.

Development of functional electrospun fiber mats for potential wound healing and blood conservation

Event Abstract Back to Event Development of functional electrospun fiber mats for potential wound healing and blood conservation Xiaoqiang Yang1, 2, Jayachandran Kizhakkedathu1, 2 and Donald Brooks1, 2, 3 1 University of British Columbia, Centre for Blood Research, Canada 2 University of British Columbia, Department of Pathology & Laboratory Medicine, Canada 3 University of British Columbia, Department of Chemistry, Canada Introduction: Our aim is to develop and evaluate a novel tissue sealant utilizing the universal adhesion reaction based on multivalent interactions between phosphatidyl choline (PC) lipid head groups on cell membranes and synthetic choline phosphate (CP)–containing polymers[1]. Such polymers when electrospun into pads should both adhere to solid tissue and bind red blood cells (RBCs) and platelets to arrest bleeding at sites of tissue damage or surgery where vascular integrity is breached. These polymer webs should meet the mechanical and functional requirements for wound healing and blood conservation applications[2]-[5]. Materials and Methods: A nano scale fiber web consisting of a random copolymer containing the backbone of ε-caprolactone and its derivative with a pendent hydrophilic segment bearing functional CP groups was prepared by the electrospinning process. To achieve the copolymer, a new cyclic ester, γ-(2-bromo-2-methly propionyl)-ε-caprolactone, containing a pendent-activated alkyl bromide functional group was prepared[6]. This new monomer serves as both a monomer for ring-opening polymerization (ROP) with ε-caprolacone as well as an initiator for controlled atom transfer radical polymerization (ATRP). The random co-poly(caprolactone) via ROP was tuned to make a suitable candidate for the electrospin process, balancing hydrophobicity, hydrophilicity and the density of functional groups by adjusting the ratio of new monomer and ε-caprolactone. The synthesis of poly(ε-caprolactone)-graft- poly(2-(2-(2-(2-azidoethoxy) -ethoxy)ethoxy)ethyl methacrylate) was via a grafting-from technique, where poly(caprolactone) with pendent isobutyryl bromide groups acted as macroinitiator to initiate the ATRP azido monomer to yield the grafted copolymer containing a backbone of poly(caprolactone) and dispersed side chains of poly(methacrylate) with multiple azido groups. Finally, pre-prepared prop-2-ynyle phosphatidylcholine (CP monomer) was clicked onto the above grafted copolymer via the reaction between the pendent azido groups of the copolymer and the alkyne group of CP monomer. The CP monomer (prop-2-ynyle phosphatidylcholine) was prepared following our previously reported method[1]. The designed copolymers were characterized with NMR and FTIR to determine the MW and presence of functional groups and the electrospun web with SEM. Results and Discussion: Human RBCs incubated with the CP web formed a uniform layer on the mat surface attributed to multivalent interactions between CP groups on the web and PC groups on the cell membrane, demonstrating the material’s potential for blood conservation and sealing. Incubation in isotonic whole blood with reduced ionic strength resulted in enhanced adhesion and supports an electrostatic mechanism for the CP-PC association. Conclusion: We anticipate that this functional fiber mat will prove to be a fundamentally new and effective biomaterial for wound dressing and blood conservation practice.

Synthesis and Linear Viscoelasticity of Polystyrene Stars with a Polyketone Core

We report on a novel synthetic route to synthesize relatively large quantities of polystyrene (PS) star polymers with targeted arm functionality and molar mass and their theological properties in the molten state. The synthetic route involves grafting styrene monomers onto a modified (aliphatic, alternating) polyketone backbone with a specific number of initiating grafting sites using controlled atom transfer radical polymerization (ATRP). Several polyketone precursors were used. This resulted in a large array of star polystyrenes with nonspherical cores and varying average arm length and number of arms. Their linear viscoelasticity was investigated and discussed in the context of the known response of anionically synthesized stars. Using a powerful characterization toolbox, including state-of-the-art interaction chromatography, rheometry, and tube modeling via the branch-on-branch (BoB) algorithm, we have assessed the viscoelasticity of these star polymers quantitatively. In particular, we have demonstrated a variability in molecular structure, which differs substantially from their anionically synthesized counterparts. Hence, whereas this new family of star polymers is not recommended for fundamental studies of polymer physics such as the molecular origin of relaxation mechanisms without prior extensive fractionation, they could be used in studies of mixtures as well as industrially relevant processing operations that require large amounts of polymeric stars.

An investigation of the morphology of Langmuir films based on molecular polyimide brushes containing magnetite nanoparticles

Molecular brushes having a polyimide (PI) backbone with degree of polycondensation n = 33 and polymethylmethacrylate (PMMA) side chains with two different degrees of polymerization (m = 63 and m = 114) were synthesized by the method of controlled atom transfer radical polymerization. Hydrophobic magnetite nanoparticles of a size of 18 ± 2 nm were prepared. Langmuir monolayers on the basis of the polyimide brushes and composite monolayers, containing magnetite nanoparticles with a hydrophobic surface, were formed at the water/air interface. It is found that, in the condensed state of the monolayer at the surface pressure values from 25 to 40 mN/m, the limiting surface area A 0 per side chain of a brush grows with an increase in the length of PMMA side chains of polymer brushes almost by a factor of 2: from A 0 = 744 ± 64 A2 for PI-graft-PMMA-63 to A 0 = 1644 ± 50 A2 for PI-graft-PMMA-114. Increasing the magnetite solution aliquot mixed with the polymer brush solution at the ratios from 1 : 2 and 1 : 1 to 2 : 1 leads to a rise in the limiting surface area values A 0 to 1072 ± 59 A2 for the first two ratios to 2534 ± 79 A2 for the third one. The obtained monolayers were transferred onto mica by the Langmuir-Schaeffer method at different surface pressure values (0.5, 10, and 25 mN/m). With the use of the method of atomic force microscopy, it is shown that a four- to sixfold increase in the mean roughness of a composite film surface due to the inclusion of magnetite nanoparticles into the polymer brush monolayer is typical of all samples.

Graft copolymerization of 2-hydroxyethyl metacrylate onto poly(ε-caprolactone) via ATRP and investigation of its self-assembly behavior

This study aims to explore an effective route for the graft copolymerization of 2-hydroxyethyl metacrylate onto poly(e-caprolactone) via ATRP technique and investigation of its self-assembly behavior. To aim this purpose, firstly α-bromo-e-caprolactone, was synthesized by Baeyer–Villiger reaction and then used as a comonomer in the ring-opening polymerization of e-caprolactone initiated with aluminum isopropoxide to produce poly(e-caprolactone-co-α-bromo-e-caprolactone) [P(CL-co-α-BrCL)] copolymer. The resulting copolymer was used as the macroinitiator for the controlled atom transfer radical polymerization (ATRP) of 2-hydroxyethyl metacrylate to produce a biodegradable poly(e-caprolactone)-g-poly(2-hydroxyethyl metacrylate) [P(CL-g-HEMA)] graft copolymer. TEM images exhibited that a core-shell type nanostructure was formed with a hydrophilic outer shell and hydrophobic inner core from this copolymer. The self-assemble micelle aggregates had well defined spherical shape with a diameter of about 40 nm. The self-assembly behavior of the graft copolymer was further characterized by 1H NMR, its thermal behavior was studied by TGA and crystallization behavior was investigated by XRD and DSC.

Controlled atom transfer radical polymerization of MMA onto the surface of high-density functionalized graphene oxide

We report on the grafting of poly(methyl methacrylate) (PMMA) onto the surface of high-density functionalized graphene oxides (GO) through controlled radical polymerization (CRP). To increase the density of surface grafting, GO was first diazotized (DGO), followed by esterification with 2-bromoisobutyryl bromide, which resulted in an atom transfer radical polymerization (ATRP) initiator-functionalized DGO-Br. The functionalized DGO-Br was characterized by X-ray photoelectron spectroscopy (XPS), Raman, and XRD patterns. PMMA chains were then grafted onto the DGO-Br surface through a ‘grafting from’ technique using ATRP. Gel permeation chromatography (GPC) results revealed that polymerization of methyl methacrylate (MMA) follows CRP. Thermal studies show that the resulting graphene-PMMA nanocomposites have higher thermal stability and glass transition temperatures (Tg) than those of pristine PMMA.

Zwitterionic-Based Stainless Steel with Well-Defined Polysulfobetaine Brushes for General Bioadhesive Control

Stainless steels are widely used as orthopaedic and dental implant; however, bioadhesion in the case of thrombosis, inflammation, and infection is one of their major limitations. One way to tackle this problem is to graft the stainless steel surface with a zwitterionic polymer known for being anti-bioadhesive. Controlled atom transfer radical polymerization (ATRP) of zwitterionic poly(sulfobetaine methacrylate) (polySBMA) grafted from biomedical grade stainless steel surface was employed in this study. The interactions of polySBMA-grafted surfaces with biomacromolecules were demonstrated in vitro by the adhesion tests of plasma protein, blood cells, human MG63 osteoblast- and HT1080 fibroblast-like cells in biological complex media to evaluate their bioadhesive properties. Anti-microbial effects were also assessed for two most ordinary seen clinical bacteria, i.e., Escherichia coli and Staphylococcus epidermidis. Results showed that polySBMA-grafted surface exhibited evident bioadhesion resistance and conferring antibacterial efficacy. This work is also dedicated to deduce the effectiveness of polySBMA brushes' conformational structure on the prevention of bioadhesion. To this aim, the anti-bioadhesive effect of polySBMA brushes prepared by dopamine- and silane-surfaced immobilization method was evaluated. Results show that polySBMA grafted from immobilized polydopamine interfacial layers achieved better bioadhesion resistance, which could be causally related to their greater grafting coverage, flexible brush conformational structures, and greater hydration capabilities.

Epoxy functionalized polymethacrylates based on various multifunctional d‐glucopyranoside acetals

The synthesis of acetal‐derived d‐glucopyranosides with a various number of hydroxyl groups (the first step, acetalization) and their modified forms with bromoester groups (the second step, esterification) are presented here. The latter, due to the type of functional groups, can be used to initiate the controlled atom transfer radical polymerization. The copolymerizations of equimolar feed of methacrylate monomers, namely, methyl methacrylate and glycidyl methacrylate, were initiated by prepared new glycoinitiators, based on methyl α‐d‐glucopyranoside (MeαdGlu) or 2‐(hydroxymethyl)phenyl‐β‐d‐glucopyranoside (salicin), in the presence of the catalyst system CuCl/dNbpy in anisole at 30 °C. The conditions were sufficient for successful synthesis of well‐defined copolymers with sugar cores sheltered by two‐, three‐, four‐, or six‐polymethacrylate segments with various polymerization degrees (DParm = 15 – 70) and low dispersity indices (Ð = 1.15–1.30). Because of the presence of oxirane groups, the star‐copolymers can be functionalized in further steps by biologically active compounds or modified to amphipilics. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2483–2494

Branched copolymers with biodegradable core and pendant oxirane groups

The reactive oxirane groups were incorporated into the macromolecule as substituents in the side chains of loosely-grafted copolymer or in the arms of star-shaped copolymer using glycidyl methacrylate (GMA) in the controlled atom transfer radical polymerization (ATRP). The branched GMA copolymers with various architectures were obtained by using hydrophobic copolymers containing six and seven units of caprolactone 2-(methacryloyloxy)ethyl ester (CLMA) functionalized with bromoester groups, and trifunctional poly(ε-caprolactone) (PCL), as well as hydrophilic tri-, and six-functional acetal derivatives of D-glucopyranosides as (macro)initiators with biodegradable and biocompatible properties. The well-defined copolymers with core-shell structures and polymerization degrees of GMA in the range of 20–100 per side chain/arm at 20–70% of monomer conversion within 1–6 h and narrow molecular weight distributions (Mw/Mn = 1.14–1.4) were obtained. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

A general synthetic strategy to prepare poly(ethylene glycol)-based multifunctional copolymers

We report polyethylene glycol-based reactive diblock copolymer as well as random copolymer scaffolds that can be transformed into desired bifunctional copolymers in two synthetic steps. Synthesis of the general scaffolds is achieved via a controlled atom transfer radical polymerization process while the functional groups are introduced via thiol–epoxy ‘click’ and esterification reactions.