Living radical polymerization of acrylonitrile catalyzed by copper with a high concentration of radical initiator and its application in removal of Ag(I) after modification

In this study, we reported the synthesis of polyacrylonitrile (PAN) via living radical polymerization in N, N‐dimethylformamide using carbon tetrachloride as initiator, copper(II) chloride (CuCl₂)/hexamethylenetetramine as catalyst system, and 2,2‐azobisisobutyronitrile as a high concentration of thermal radical initiator. The polymerization proceeded in controlled/living manner as indicated by first‐order kinetics of the polymerization with respect to the monomer concentration, linear increase of the molecular weight with monomer conversion and narrow polydispersity. Higher polymerization rate and narrower molecular weight distributions were observed with CuCl₂ less than 50 ppm. The rate of polymerization showed a trend of increase along with temperature. The modified PAN containing amidoxime group was used for extraction of Ag(I) ions from aqueous solutions. The adsorption kinetics data indicated that the adsorption process followed pseudo‐second‐order rate model. The isotherm adsorption process could be described by the Freundlich isotherm model. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Photoinduced ATRP of acrylonitrile with aniline as photoinitiator

Photo-mediated atom transfer radical polymerization (ATRP) of acrylonitrile (AN) was carried out at 25°C in N,N-dimethyl formamide (DMF) with aniline as photoinitiator. Polyacrylonitrile (PAN) with predictable average molecular weight and narrow molecular weight distribution was synthesized with 2-Bromopropionitrile (BPN) as ATRP initiator and FeCl₃·6H₂O/Triphenylphosphine (PPh₃) as the catalyst. The obtained kinetics showed that the photoinduced Fe-mediated ATRP of AN provided a route to synthesize well defined PAN with narrow molecular weight distribution (M_w/M_n). The living character of photoinduced Fe-mediated ATRP of AN was verified by the linear increase of molecular weights with monomer conversion and the molecular weights are in good agreement with the theoretic values. In addition, the chain extension experiments were successfully conducted under the same conditions. The periodic light on-off process was investigated for the photoinduced Fe-mediated ATRP of AN. The obtained PAN was characterized by ¹H nuclear magnetic resonance and gel permeation chromatography. The brominated PAN was used to perform chain-extension with AN as macroinitiator in order to verify the living nature of photoinduced ATRP of AN-Br.     

Synthesis of poly(methyl methacrylate) via ARGET ATRP and study of the effect of solvents and temperatures on its polymerization kinetics

This investigation reports the synthesis of poly(methyl methacrylate) via activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and studies the effect of solvents and temperature on its polymerization kinetics. ARGET ATRP of methyl methacrylate (MMA) was carried out in different solvents and at different temperatures using CuBr₂ as catalyst in combination with N,N,N′,N″,N″‐pentamethyldiethylenetriamine as a ligand. Methyl 2‐chloro propionate was used as ATRP initiator and ascorbic acid was used as a reducing agent in the ARGET ATRP of MMA. The conversion was measured gravimetrically. The semilogarithmic plot of monomer conversion versus time was found to be linear, indicating that the polymerization follows first‐order kinetics. The linear polymerization kinetic plot also indicates the controlled nature of the polymerization. N,N‐Dimethylformamide (DMF), tetrahydrofuran (THF), toluene, and methyl ethyl ketone were used as solvents to study the effect on the polymerization kinetics. The effect of temperature on the kinetics of the polymerization was also studied at various temperatures. It has been observed that polymerization followed first‐order kinetics in every case. The rate of polymerization was found to be highest (k_app = 6.94 × 10⁻³ min⁻¹) at a fixed temperature when DMF was used as solvent. Activation energies for ARGET ATRP of MMA were also calculated using the Arrhenius equation.     

Synthesis of polyacrylonitrile by single‐electron transfer‐living radical polymerization using Fe(0) as catalyst and its adsorption properties after modification

Fe(0) was firstly used as single‐electron transfer‐living radical polymerization catalyst for acrylonitrile polymerization using carbon tetrachloride as initiator, hexamethylenetetramine as N‐ligand, and N,N‐dimethylformamide as the solvent at 65 °C. First‐order kinetic studies indicated that this polymerization proceeded in a “living”/controlled manner. The living nature of the polymerization was also confirmed by chain extension of methyl methacrylate with polyacrylonitrile (PAN) as macroinitiator. Furthermore, PAN was modified with NH₂OH·HCl to generate amidoxime groups for extraction of heavy metal ions (Hg²⁺) from aqueous solutions. Fourier transformed infrared spectroscopy was performed to characterize chemical composition and structure. The adsorption property of Hg²⁺ was investigated at different pH values of aqueous solutions and distilled water. The maximal saturated adsorption capacity of Hg²⁺ was 4.8 mmol g^?1. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Atom transfer radical polymerization of N‐vinyl carbazole: Optimization to characterization

The homopolymerization of N‐vinylcarbazole was performed with atom transfer radical polymerization (ATRP) with Cu(I)/Cu(II)/2,2′‐bipyridine (bpy) as the catalyst system at 90 °C in toluene. N‐2‐Bromoethyl carbazole was used as the initiator, and the optimized ratio of Cu(I) to Cu(II) was found to be 1/0.3. The resulting homopolymer, poly(N‐vinylcarbazole) (PVK), was formed after a monomer conversion of 76% in 20 h. The molecular weight as well as the polydispersity index (PDI) showed a linear relation with the conversion, which showed control over the polymerization. A semilogarithmic plot of the monomer conversion with time was linear, indicating the presence of constant active species throughout the polymerization. The initiator efficiency and the effect of the variation of the initiator concentration on the polymerization were studied. The effects of the addition of CuBr₂, the variation of the catalyst concentration with respect to the initiator, and CuX (X = Br or Cl) on the kinetics of homopolymerization were determined. With Cu(0)/CuBr₂/bpy as the catalyst, faster polymerization was observed. For a chain‐extension experiments, PVK (number‐average molecular weight = 1900; PDI = 1.24) was used as a macroinitiator for the ATRP of methyl methacrylate, and this resulted in the formation of a block copolymer that gave a monomodal curve in gel permeation chromatography. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1745–1757, 2006     

Atom transfer radical polymerization of acrylates in an ionic liquid: Synthesis of block copolymers

Atom transfer radical polymerization (ATRP) of acrylates in ionic liquid, 1‐butyl‐3‐methylimidazolium hexaflurophospate, with the CuBr/CuBr₂/amine catalytic system was investigated. Sequential polymerization was performed by synthesizing AB block copolymers. Polymerization of butyl acrylate (monomer that is only partly soluble in an ionic liquid forming a two‐phase system) proceeded to practically quantitative conversion. If the second monomer (methyl acrylate) is added at this stage, polymerization proceeds, and block copolymer formed is essentially free of homopolymer according to size exclusion chromatographic analysis. The number‐average molecular weight of the copolymer is slightly higher than calculated, but the molecular weight distribution is low (M_w/M_n = 1.12). If, however, methyl acrylate (monomer that is soluble in an ionic liquid) is polymerized at the first stage, then butyl acrylate in the second‐stage situation is different. Block copolymer free of homopolymer of the first block (with M_w/M_n = 1.13) may be obtained only if the conversion of methyl acrylate at the stage when second monomer is added is not higher than 70%. Matrix‐assisted laser desorption/ionization time‐of‐flight analysis confirmed that irreversible deactivation of growing macromolecules is significant for methyl acrylate polymerization at a monomer conversion above 70%, whereas it is still not significant for butyl acrylate even at practically quantitative conversion. These results show that ATRP of butyl acrylate in ionic liquid followed by addition of a second acrylate monomer allows the clean synthesis of block copolymers by one‐pot sequential polymerization even if the first stage is carried out to complete conversion of butyl acrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2799–2809, 2002     

Atom transfer radical polymerization of methyl methacrylate using copper-based homogeneous and heterogeneous catalysts

This study aimed at polymerization of methyl methacrylate with novel catalysts in the atom transfer radical polymerization (ATRP) condition at 90 °C. This was accomplished using CuBr/N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (CuBr–AEAPTMS) as a homogeneous catalyst and one time with CuBr@AEAPTMS/SBA-15 as a heterogeneous catalyst. Catalysts were characterized using TGA, FT-IR, and UV–Vis spectroscopy. The structural analysis of the polymer was carried out by ¹³C NMR spectroscopy and GPC. Three characteristic parts of polymer produced by ATRP method including the initiator, monomer units, and end group was shown in ¹³C NMR spectra. In addition, the presence of C–Br unit showed that the polymerization process is alive. The ¹H NMR analysis was used for kinetic investigation of methyl methacrylate polymerization with homogeneous and heterogeneous catalysts that showed high monomer conversion (98 and 90% after 35 min, respectively) and good control of molecular weight with a dispersity (Р= 1.5–1.7). In addition, the plot of ln ([monomer]₀/[monomer] _t ) versus time gave linear relationships indicating a constant concentration of the propagating species throughout the polymerization. Finally, the results of the polymerization using heterogeneous catalyst compared with homogeneous catalyst revealed that it was according to ATRP method.     

Adsorption properties of amidoximated porous acrylonitrile/methyl acrylate copolymer beads for Ag (I)

Porous a crylonitrile (AN)/methyl acrylate (MA) copolymer beads were synthesized by suspended emulsion polymerization and amidoximated for the purpose of Ag⁺ adsorption. Optimum amidoximation temperature and time were determined by following the adsorption capacity for Ag⁺. The results showed that amidoximated AN/MA (AO AN/MA) with the amidoximation temperature 70°C and amidoximation time 20 hr had a relatively higher adsorption capacity for Ag⁺. The effect of pH on adsorption for Ag⁺ was studied; the highest adsorption capacity presented at pH 5.0. Adsorption kinetics and isotherms of AO AN/MA copolymer beads for Ag⁺ were also investigated. The kinetics data indicated that the adsorption process was governed by the film diffusion and followed both pseudo‐first‐order and pseudo‐second‐order rate model. The isotherms indicated that adsorption capacities increased with equilibrium concentration and temperature. The Langmuir model and Sips model could describe the isothermal process. Thermodynamic analysis revealed that the adsorption behaviors of Ag⁺ ions on AO AN/MA could be considered as endothermic and physical sorption process. Copyright © 2010 John Wiley & Sons, Ltd.     

Kinetic study of in situ normal and AGET atom transfer radical copolymerization of n–butyl acrylate and styrene: Effect of nanoclay loading and catalyst concentration

The effect of clay nanolayers and catalyst concentration on the kinetics of atom transfer radical copolymerization of styrene and butyl acrylate initiated by activators generated by electron transfer (AGET initiation system) or an alkyl halide (normal initiation system) was studied. Monomer conversion was studied by attenuated total reflection–Fourier transform infrared spectroscopy, and also proton nuclear magnetic resonance (¹H NMR) spectroscopy was utilized to evaluate the heterogeneity in the composition of poly(styrene‐co‐butyl acrylate) chains. A decrease in the copolymerization rate of styrene and butyl acrylate in the presence of clay platelets was observed since clay layers confine the accessibility of monomer and growing radical chains. Considering the linear first‐order kinetics of the polymerization, successful AGET and normal atom transfer radical polymerization (ATRP) in the presence of clay nanolayers were carried out. Consequently, poly(styrene‐co‐butyl acrylate) chains with narrow molecular weight distribution and low polydispersity indices (1.13–1.15) were obtained. The linearity of ln([M]₀/[M]) versus time and molecular weight distribution against conversion plots indicates that the proportion of propagating radicals is almost constant during the polymerization, which is the result of insignificant contribution of termination and transfer reactions. Controlled synthesis of poly(styrene‐co‐butyl acrylate)/clay is implemented with the diminishing catalyst concentration of copper(I) bromide/N,N,N′,N′′,N′′‐pentamethyl diethylene triamine without affecting the copolymerization rate of normal ATRP. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 789–799, 2012     

Atom transfer radical polymerization of functional monomers employing Cu‐based catalysts at low concentration: Polymerization of glycidyl methacrylate

Initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) of an epoxide‐containing monomer, glycidyl methacrylate (GMA), was successfully carried out using low concentration of catalyst (ca. 105 ppm) at 60 °C in anisole. The copper complex of tris(2‐pyridylmethyl)amine was used as the catalyst, diethyl 2‐bromo‐2‐methylmalonate as the initiator, and 2,2′‐azobisisobutyronitrile as the reducing agent. When moderate degrees of polymerization were targeted (up to 200), special purification of the monomer, other than removal of the polymerization inhibitor, was not required to achieve good control. To synthesize well‐defined polymers with higher degrees of polymerization (600), it was essential to use very pure monomer, and polymers of molecular weights exceeding 50,000 g mol^?1 and M_w/M_n = 1.10 were prepared. The developed procedures were used to chain‐extend bromine‐terminated poly(methyl methacrylate) macroinitiator prepared by activators regenerated by electron transfer (ARGET) ATRP. The Sn^II‐mediated ARGET ATRP technique was not suitable for the polymerization of GMA and resulted in polymers with multimodal molecular weight distributions. This was due to the occurrence of epoxide ring‐opening reactions, catalyzed by Sn^II and Sn^IV. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

In situ atom transfer radical polymerization of styrene with a tetraethylthiuram disulfide/copper bromide/2,2′‐bipyridine initiating system

The living radical polymerization of styrene in bulk was successfully performed with a tetraethylthiuram disulfide/copper bromide/2,2′‐bipyridine (bpy) initiating system. The initiator Et₂NCS₂Br and the catalyst cuprous bromide (CuBr) were produced from the reactants in the system through in situ atom transfer radical polymerization (ATRP). A plot of natural logarithm of the ratio of original monomer concentration to monomer concentration at present, ln([M]₀/[M]) versus time gave a straight line, indicating that the kinetics was first‐order. The number‐average molecular weight from gel permeation chromatography (GPC) of obtained polystyrenes did not agree well with the calculated number‐average molecular weight but did correspond to a 0.5 initiator efficiency. The polydispersity index (i.e., the weight‐average molecular weight divided by the number‐average molecular weight) of obtained polymers was as low as 1.30. The resulting polystyrene with α‐diethyldithiocarbamate and ω‐Br end groups could initiate methyl methacrylate polymerization in the presence of CuBr/bpy or cuprous chloride/bpy complex catalyst through a conventional ATRP process. The block polymer was characterized with GPC, ¹H NMR, and differential scanning calorimetry. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4001–4008, 2001     

Preparation of poly(acrylic acid)‐b‐polystyrene by two‐step atom transfer radical polymerization in supercritical carbon dioxide

It is known that it is difficult to polymerize carboxylic acid‐based monomer by atom transfer radical polymerization (ATRP) in polar solvents due to the protonation of ligand caused by acidic dissociation of the monomer. In this study, precipitation reverse ATRP of acrylic acid (AA) was carried out in supercritical carbon dioxide (scCO₂), which is a nonpolar solvent to dissolve transition metal complexes, at 30 MPa and 45 °C. The polymerization proceeded smoothly and the conversion reached 86% for 3 h. After vending of scCO₂, a dry poly(acrylic acid) (PAA) powder was obtained. Weight‐average molecular weight and polydispersity of the methylated PAA, which were measured by gel‐permeation chromatography after methyl esterification, were 3.5 × 10⁴ and 2.07, respectively, indicating that the precipitation reverse ATRP proceeded with a bad control manner. However, chain extension of the methylated PAA with styrene was possible by ATRP in a bulk system. Moreover, PAA‐b‐polystyrene was successfully prepared in scCO₂ directly by two‐step ATRP, although its molecular weight distribution was broad. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Phosphorylated polyacrylonitrile‐based electrospun nanofibers for removal of heavy metal ions from aqueous solution

The phosphorylated polyacrylonitrile‐based (P‐PAN) nanofibers were prepared by electrospinning technique and used for removal of Cu²⁺, Ni²⁺, Cd²⁺, and Ag⁺ from aqueous solution. The morphological and structural properties of P‐PAN nanofibers were characterized by scanning electron microscope and Fourie transform infrared spectra. The P‐PAN nanofibers were evaluated for the adsorption capacity at various pH, contact time, and reaction temperature in a batch system. The reusability of P‐PAN nanofibers for the removal of heavy metal ions was also determined. Adsorption isotherms and adsorption kinetics were also used to examine the fundamental adsorption properties. It is found that the P‐PAN nanofibers show high efficiency, and the maximal adsorption capacities of metal ions as calculated from the Langmuir model were 92.1, 68.3, 14.8, and 51.7 mg/g, respectively. The kinetics of the heavy metal ions adsorption were found to follow pseudo‐second‐order rate equation, suggesting chemical adsorption can be regarded as the major factor in the adsorption process. Sorption/desorption results reveal that the obtained P‐PAN nanofibers can remain high removal efficiency after four cycles.     

AGET ATRP of acrylonitrile using 1,1,4,7,10,10‐hexamethyltriethylenetetramine as both ligand and reducing agent

Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) initiated by ethyl 2‐bromoisobutyrate was approached for the first time using 1,1,4,7,10,10‐hexamethyltriethylenetetramine (HMTETA) and 1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) as both ligand and reducing agent. AGET ATRP of AN with HMTETA as both ligand and reducing agent was better controlled than with PMDETA as both ligand and reducing agent under the same experimental conditions. With an increase content of HMTETA, the polymerization provided an accelerated reaction rate and a broader polymer molecular weight distribution. The rate of polymerization with DMF as solvent was faster than with acetonitrile, cyclohexanone, toluene, and xylene as solvents. The polymerization apparent activation energy was calculated to be 45.7 kJ mol^?1. The end functionality of polyacrylonitrile (PAN) was confirmed by ¹H NMR spectroscopy. The living feature of PAN was verified by chain extensions of PAN with methyl methacrylate and AN. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 128–133, 2010     

Controlled polymerization of methacrylates at ambient temperature using trithiocarbonate chain transfer agents via SET‐RAFT–cyclohexyl methacrylate: A model study

Controlled radical polymerization of cyclohexyl methacrylate (CHMA), at ambient temperature, using various chain transfer agents (CTAs) is successfully demonstrated via single electron transfer‐radical addition fragmentation chain transfer (SET‐RAFT). Well‐controlled polymerization with narrow molecular weight distribution (M_w/M_n) < 1.25 was achieved. The polymerization rate followed first‐order kinetics with respect to monomer conversion, and the molecular weight of the polymer increased linearly up to high conversion. A novel, fluorescein‐based initiator, a novel fluorescent CTA and two other CTAs comprising of butane thiol trithiocarbonate with cyano (CTA 1) and carboxylic acid (CTA 3) as the end group were synthesized and characterized. The polymerization is observed to be uncontrolled under SET and less controlled under atom transfer radical polymerization (ATRP) condition. CTA 2 and 3 produces better control in propagation compared with CTA 1, which may be attributed to the presence of R group that undergoes ready fragmentation to radicals, at ambient temperature. The poly(cyclohexyl methacrylate) [P(CHMA)] prepared through ATRP have higher fluorescence intensity compared with those from SET‐RAFT, which may be attributed to the quenching of fluorescence by the trithiocarbonate and the long hydrocarbon chain. It is observed that block copolymers P(CHMA‐b‐t‐BMA) produced from P(CHMA) macroinitiators synthesized via SET‐RAFT result in lower polydispersity index in comparison with those synthesized via ATRP. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and characterization of poly(methyl methacrylate)‐block‐poly(methylphenylsilane)‐ block‐poly(methyl methacrylate) by atom transfer radical polymerization

ABA block copolymers of methyl methacrylate and methylphenylsilane were synthesized with a methodology based on atom transfer radical polymerization (ATRP). The reaction of samples of α,ω‐dihalopoly(methylphenylsilane) with 2‐hydroxyethyl‐2‐methyl‐2‐bromoproprionate gave suitable macroinitiators for the ATRP of methyl methacrylate. The latter procedure was carried out at 95 °C in a xylene solution with CuBr and 2,2‐bipyridine as the initiating system. The rate of the polymerization was first‐order with respect to monomer conversion. The block copolymers were characterized with ¹H NMR and ¹³C NMR spectroscopy and size exclusion chromatography, and differential scanning calorimetry was used to obtain preliminary evidence of phase separation in the copolymer products. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 30–40, 2003     

Graft copolymers of polyethylene by atom transfer radical polymerization

Poly(ethylene‐g‐styrene) and poly(ethylene‐g‐methyl methacrylate) graft copolymers were prepared by atom transfer radical polymerization (ATRP). Commercially available poly(ethylene‐co‐glycidyl methacrylate) was converted into ATRP macroinitiators by reaction with chloroacetic acid and 2‐bromoisobutyric acid, respectively, and the pendant‐functionalized polyolefins were used to initiate the ATRP of styrene and methyl methacrylate. In both cases, incorporation of the vinyl monomer into the graft copolymer increased with extent of the reaction. The controlled growth of the side chains was proved in the case of poly(ethylene‐g‐styrene) by the linear increase of molecular weight with conversion and low polydispersity (M_w /M_n < 1.4) of the cleaved polystyrene grafts. Both macroinitiators and graft copolymers were characterized by ¹H NMR and differential scanning calorimetry. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2440–2448, 2000     

Synthesis of high performance polyacrylonitrile by RASA SET–LRP in the presence of Mg powder

High performance polyacrylonitrile (PAN) was prepared with Mg powder as both reducing agent (RA) and supplemental activator (SA) by single electron transfer‐living radical polymerization (RASA SET‐LRP). First‐order kinetics of polymerization with respect to monomer concentration, linear increase of molecular weight, and narrow polydispersity with monomer conversion, and the obtained high isotacticity PAN indicate that RASA SET‐LRP in the presence of Mg powder could simultaneously control molecular weight and tacticity of PAN. compared with that obtained with ascorbic acid (VC) as RA, an obvious increase in isotacticity of PAN was observed. the block copolymer pan‐b‐pAN with molecular weight at 112,460, polydispersity at 1.33, and isotacticity at 0.314 was successfully prepared. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3328–3332     

Atom transfer radical polymerization of n‐butyl acrylate catalyzed by CuBr/N‐(n‐hexyl)‐2‐pyridylmethanimine

The homogeneous atom transfer radical polymerization (ATRP) of n‐butyl acrylate with CuBr/N‐(n‐hexyl)‐2‐pyridylmethanimine as a catalyst and ethyl 2‐bromoisobutyrate as an initiator was investigated. The kinetic plots of ln([M]₀/[M]) versus the reaction time for the ATRP systems in different solvents such as toluene, anisole, N,N‐dimethylformamide, and 1‐butanol were linear throughout the reactions, and the experimental molecular weights increased linearly with increasing monomer conversion and were very close to the theoretical values. These, together with the relatively narrow molecular weight distributions (polydispersity index ～ 1.40 in most cases with monomer conversion > 50%), indicated that the polymerization was living and controlled. Toluene appeared to be the best solvent for the studied ATRP system in terms of the polymerization rate and molecular weight distribution among the solvents used. The polymerization showed zero order with respect to both the initiator and the catalyst, probably because of the presence of a self‐regulation process at the beginning of the reaction. The reaction temperature had a positive effect on the polymerization rate, and the optimum reaction temperature was found to be 100 °C. An apparent enthalpy of activation of 81.2 kJ/mol was determined for the ATRP of n‐butyl acrylate, corresponding to an enthalpy of equilibrium of 63.6 kJ/mol. An apparent enthalpy of activation of 52.8 kJ/mol was also obtained for the ATRP of methyl methacrylate under similar reaction conditions. Moreover, the CuBr/N‐(n‐hexyl)‐2‐pyridylmethanimine‐based system was proven to be applicable to living block copolymerization and living random copolymerization of n‐butyl acrylate with methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3549–3561, 2002     

Polymerization of acrylates by atom transfer radical polymerization. Homopolymerization of 2-hydroxyethyl acrylate

The application of atom transfer radical polymerization (ATRP) to the homopolymerization of 2-hydroxyethyl acrylate, a functional monomer, is reported. The polymerizations exhibit first-order kinetics, and molecular weights increase linearly with conversion. Polydispersities remain low throughout the polymerization (M_w/M_n ≈ 1.2). Reactions were conducted in bulk and in 1 : 1 (by volume) aqueous solution; the latter demonstrates the resilience of ATRP to protic media. Analysis of poly(2-hydroxyethyl acrylate) by MALDI-MS and ¹H-NMR shows M_n,exp to be much closer to M_n,th than those observed by SEC using polystyrene standards. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1417–1424, 1998