Atom Transfer Radical Polymerization Of St Research Articles

Synthesis, characterization and thermal properties of polystyrene–poly(lactic acid)–polystyrene triblock copolymer via atom transfer radical polymerization

Polystyrene (PS)–poly(lactic acid) (PLA)–PS triblock copolymer is prepared with PLA and styrene (St) via atom transfer radical polymerization (ATRP). The structure and thermal properties of the copolymer are analyzed by infrared spectroscopy, gel permeation chromatography, nuclear magnetic resonance, thermogravimetry, differential scanning calorimetry and alcoholysis. The ATRP of St using bromine-terminated PLA as the initiator exhibits first-order kinetics and a low-molecular-weight distribution ( Mw/ Mn ≈ 1.5). The thermal stability of PLA is improved by copolymerization. Both the initial temperature of thermal decomposition and glass transition temperature are increased with an increasing length of PS block.

Synthesis, surface properties, and morphologies of poly[methyl(3,3,3‐trifluoropropyl)siloxane]‐b‐polystyrene‐b‐poly(tert‐butyl acrylate) triblock copolymers by a combination of anionic ROP and ATRP

AbstractA series of well‐defined poly[methyl(3,3,3‐trifluoropropyl)siloxane]‐b‐polystyrene‐b‐poly(tert‐butyl acrylate) (PMTFPS‐b‐PS‐b‐PtBA) triblock copolymers were prepared by a combination of anionic ring‐opening polymerization of 1,3,5‐trimethyl‐1,3,5‐tris(3′,3′,3′‐trifluoropropyl)cyclotrisiloxane (F3), and atom transfer radical polymerization (ATRP) of styrene (St) and tert‐butyl acrylate (tBA), using the obtained α‐bromoisobutyryl‐terminal PMTFPS (PMTFPS‐Br) as the macroinitiators. The ATRP of St from PMTFPS‐Br, as well as the ATRP of tBA from the obtained PMTFPS‐b‐PS‐Br macroinitiators, has typical characteristic of controlled/living polymerization. The results of contact angle measurements for the films of PMTFPS‐b‐PS‐b‐PtBA triblock copolymers demonstrate that the compositions have an effect on the wetting behavior of the copolymer films. For the copolymer films with different compositions, there may be different macroscale or nanoscale structures on the outmost layer of the copolymer surfaces. The films with high content of PtBA blocks exhibit almost no ordered microstructures on the outmost layer of the copolymer surfaces, even though they have microphase‐separated structures in bulk. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Probing the effects of π-π stacking on the controlled radical polymerization of styrene and fluorinated styrene

The addition of the π–π stacking agent octafluorotoluene (OFT) resulted in up to a 50% reduction in monomer conversion after 24 h for atom transfer radical polymerization (ATRP) reactions of styrene, when performed at 85 °C with 1 eq of OFT compared with styrene in the initial reaction mixture. Monitoring the progress showed that the ATRP of styrene in the presence of either OFT or hexafluorobenzene (HFB) maintained a linear relationship between monomer conversion and number average molecular weights, while showing a first order rate dependence on monomer. The effects of π–π stacking on the KATRP could be overcome by using adjusting the redox activity of the metal-ligand complex while maintaining reaction temperatures of 85 °C. Further experiments showed that nitroxide-mediated polymerizations of St were affected to an identical extent by the presence of the π–π stacking agent HFB. The ATRP of pentafluorostyrene (PFSt) in the presence of π–π stackers benzene or toluene showed an increase in monomer conversion compared with reactions in their absence, consistent with Mn π–π stacking increasing the stability of the active radical. Interactions between the π–π stacking agents OFT and HFB and the aromatic groups in the ATRP of St or PFSt were verified by 1H NMR analysis. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Synthesis of a novel graft copolymer with hyperbranched poly(glycerol) as core and “Y”-shaped polystyrene-b-poly(ethylene oxide)2 as side chains

The graft copolymers composed of ''Y''-shaped polystyrene-b-poly(ethylene oxide)2 (PS-b-PEO2) as side chains and hyperbranched poly(glycerol) (HPG) as core were synthe- sized by a combination of ''click'' chemistry and atom transfer radical polymerization (ATRP) via ''graft from'' and ''graft onto'' strategies. Firstly, macroinitiators HPG-Br were obtained by esterification of hydroxyl groups on HPG with bromoisobutyryl bromide, and then by ''graft from'' strategy, graft copolymers HPG-g-(PS-Br) were synthesized by ATRP of St and further HPG-g-(PS-N3) were prepared by azidation with NaN3. Then, the precursors (Bz-PEO)2-alkyne with a single alkyne group at the junction point and an inert benzyl group at each end was synthesized by sequentially ring-opening polymerization (ROP) of EO using 3-((1-ethoxyethyl)-ethoxyethyl)-1,2-propanediol (EEPD) and diphenylmethylpotassium (DPMK) as coinitiator, termination of living polymeric species by benzyl bromide, recovery of protected hydroxyl groups by HCl and modification by propargyl bromide. Finally, the ''click'' chemistry was con- ducted between HPG-g-(PS-N3) and (Bz-PEO)2-alkyne in the presence of N,N,N 0 ,N 00 ,N''-pentamethyl diethylenetriamine (PMDETA)/CuBr system by ''graft onto'' strategy, and the graft copolymers were characterized by SEC, 1 H NMR and FTIR in details. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5856-5864, 2010

Effect of Initiator and Ligand Structures on ATRP of Styrene and Methyl Methacrylate Initiated by Alkyl Dithiocarbamate

Atom transfer radical polymerization (ATRP) of styrene (St) and methyl methacrylate (MMA) initiated by various alkyl diethyldithiocarbamate (DC) initiators was successfully carried out in the presence of copper catalysts with nitrogen-based ligands. Well-controlled polymerizations with narrow molecular weight distribution (Mw/Mn < 1.1 (St) and Mw/Mn < 1.2 (MMA)) were achieved in both polymerizations. The polymerization rate followed first-order kinetics with respect to monomer conversion, and the molecular weight of the polymers increased linearly up to high conversion. Initiation efficiency of both polymerizations was strongly dependent on the structure of a DC. The results of 1H NMR analysis of low-mass model compounds and chain extension confirmed that well-defined polystyrene bearing a DC group as the active chain end was obtained via ATRP of St with a DC initiator. Ligand structure and ligand/copper ratio also strongly affected the degree of control attained in the polymerization. Activation rate constants and equilibrium constants of ATRP with DC initiators and copper complexes were determined. The results of cyclic voltammetry with the CuIIDC2 complex indicated that it has more negative reduction potential and, consequently, higher (pseudo)halidophilicity than those of CuIIBr2 or CuIICl2 with the same ligand Me6TREN.

Synthesis and applications of triblock and multiblock copolymers using telechelic oligopropylene

Isotactic polypropylene (iPP)–polystyrene (PS) and iPP–poly(methyl methacrylate) (PMMA) multiblock copolymers were synthesized by atom transfer radical coupling (ATRC) of PS–iPP–PS and PMMA–iPP–PMMA triblock copolymers obtained by atom transfer radical polymerization (ATRP) of styrene (St) and methyl methacrylate (MMA), respectively, using α,ω-dibromoisobutyrateoligopropylene (iPP–Br) as a bifunctional macroinitiator. The iPP–Br was prepared by hydroxylation and subsequent esterification of telechelic oligopropylene having terminal vinylidene double bonds at both ends obtained by controlled thermal degradation of iPP. ATRP of St and (meth) acrylic monomers using iPP–Br formed the corresponding triblock copolymers. It was confirmed that the PMMA–iPP–PMMA triblock copolymer was effective as the compatibilizer for the iPP/PMMA blend. An iPP–PS multiblock copolymer (Mn: 25 000g/mol and Mw/Mn: 4.1) was prepared by ATRC of PS–iPP–PS triblock copolymer (Mn: 8900g/mol and Mw/Mn: 1.3). ATRC with St of PMMA–iPP–PMMA triblock copolymer (Mn: 13 000g/mol and Mw/Mn: 1.4) provided an iPP–PMMA multiblock copolymer containing St chains (Mn: 39 000g/mol and Mw/Mn: 2.8).

A novel azo‐containing dithiocarbamate used for living radical polymerization of methyl acrylate and styrene

AbstractA novel azo‐containing dithiocarbamate, 1‐phenylethyl N,N‐(4‐phenylazo) phenylphenyldithiocarbamate (PPADC), was successfully synthesized and used to mediate the polymerization of methyl acrylate (MA) and styrene (St). In the presence of PPADC, the reversible addition‐fragmentation chain transfer (RAFT) polymerization was well controlled in the case of MA, however, the slightly ill‐controlled in the case of St. Interestingly, the polymerization of St could be well‐controlled when using PPADC as the initiator in the presence of CuBr/PMDETA via atom transfer radical polymerization (ATRP) technique. In the cases of RAFT polymerization of MA and ATRP of St, the kinetic plots were both of first‐order, and the molecular weight of the polymer increased linearly with the monomer conversion while keeping the relatively narrow molecular weight distribution (Mw/Mn). The molecular weight of the polymer measured by gel permeation chromatographer (GPC) was also close to the theoretical value (Mn(th)). The obtained polymer was characterized by 1H‐NMR analysis, ultraviolet absorption, FTIR spectra analysis and chain‐extension experiments. Furthermore, the photoresponsive behaviors of azobenzene‐terminated poly(methyl acrylate) (PMA) and polystyrene (PS) were similar to PPADC. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5626–5637, 2008

Chemozymatic synthesis and characterization of H-shaped triblock copolymer

The synthesis of well-defined H-shaped block copolymer based on the enzymatic ring-opening polymerization (eROP) and atom transfer radical polymerization (ATRP) is described. The dihydroxyl polycaprolactone (PCL) was synthesized by the eROP of e-caprolactone (e-CL) in the presence biocatalyst Novozyme 435 and initiator ethylene glycol. Subsequently, the resulting PCL was converted to tetrafunctional macroinitiator by the esterification with 2,2-dichloro acetyl chloride (DCAC). The H-shaped block copolymer was then synthesized by the ATRP of styrene. The polymers were characterized by NMR and GPC. Linear first-order kinetics, linearly increasing molecular weight with conversion, and low polydispersities observed from the ATRP of St showed that the polymerization was well controlled. (PSt)2-b-PCL-b-(PSt)2 block copolymers with varying molecular weight and controllable composition were obtained.

Synthesis of poly[(decanoic acid)‐block‐styrene] diblock copolymers and their self‐assembly behavior in aqueous medium

AbstractDiblock copolymers, poly[(10‐hydroxydecanoic acid)‐block‐styrene] (PHDA‐b‐PSt), were synthesized by combining enzymatic condensation polymerization of HDA and atom transfer radical polymerization (ATRP) as of St PHDA was first obtained via enzymatic condensation polymerization catalyzed by Novozyme‐435. Subsequently, one terminus of the PHDA chains was modified by reaction with α‐bromopropionyl bromide and the other terminus was protected by chlorotrimethylsilane. The resulting monofunctional macroinitiator was used subsequently in ATRP of St using CuCl/2,2′‐bipyridine as the catalyst system to afford diblock copolymers including biodegradable PHDA blocks and well‐defined PSt blocks. Polymeric nanospheres were prepared by self‐assembly of the PHDA‐b‐PSt diblock copolymers in aqueous medium. Copyright © 2008 Society of Chemical Industry

Synthesis of poly(vinyl acetate)‐graft‐polystyrene by a combination of cobalt‐mediated radical polymerization and atom transfer radical polymerization

AbstractVinyl acetate and vinyl chloroacetate were copolymerized in the presence of a bis(trifluoro‐2,4‐pentanedionato)cobalt(II) complex and 2,2′‐azobis(4‐methoxy‐2,4‐dimethylvaleronitrile) at 30 °C, forming a cobalt‐capped poly(vinyl acetate‐co‐vinyl chloroacetate). The addition of 2,2,6,6‐tetramethyl‐1‐piperidinyloxy after a certain degree of copolymerization was reached afforded 2,2,6,6‐tetramethyl‐1‐piperidinyloxy‐terminated poly(vinyl acetate‐co‐vinyl chloroacetate) (PVOAc–MI; number‐average molecular weight = 31,000, weight‐average molecular weight/number‐average molecular weight = 1.24). A 1H NMR study of the resulting PVOAc–MI revealed quantitative terminal 2,2,6,6‐tetramethyl‐1‐piperidinyloxy functionality and the presence of 5.5 mol % vinyl chloroacetate in the copolymer. The atom transfer radical polymerization (ATRP) of styrene (St) was studied with ethyl chloroacetate as a model initiator and five different Cu‐based catalysts. Catalysts with bis(2‐pyridylmethyl)octadecylamine (BPMODA) or tris(2‐pyridylmethyl)amine (TPMA) ligands provided the highest initiation efficiency and best control over the polymerization of St. The grafting‐from ATRP of St from PVOAc–MI catalyzed by copper complexes with BPMODA or TPMA ligands provided poly(vinyl acetate)‐graft‐polystyrene copolymers with relatively high polydispersity (&gt;1.5) because of intermolecular coupling between growing polystyrene (PSt) grafts. After the hydrolysis of the graft copolymers, the cleaved PSt side chains had a monomodal molecular weight distribution with some tailing toward the lower number‐average molecular weight region because of termination. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 447–459, 2007

The chemoenzymatic synthesis of AB-type diblock copolymers from a novel bifunctional initiator

A novel bifunctional initiator 2,2,2-trichloroethanol (TCE) is used for the chemoenzymatic synthesis of AB-type diblock copolymer polycaprolactone- block-polystyrene (PCL- b-PSt) by combination of two fundamentally different synthetic techniques: enzymatic ring-opening polymerization (ROP) of ε-caprolactone ( ε-CL) and atom transfer radical polymerization (ATRP) of styrene (St). The kinetic study on the TCE-initiated enzymatic ROP of ε-CL in the presence of the biocatalyst Novozyme-435 was investigated. By optimization of the reaction conditions, TCE quantitatively initiated enzymatic ROP of ε-CL. Trichloromethyl-terminated PCL macromolecules prepared in this way were subsequently employed as macroinitiators in the ATRP of St using CuCl/2,2′-bipyridine as the catalyst system to afford well-defined AB-type diblock copolymers PCL- b-PSt. The kinetic analysis of ATRP indicated a ‘living’/controlled radical polymerization. The polymeric nanospheres were prepared by the precipitation method from two resulting PCL–PSt diblock copolymers with different content ratio of PSt to PCL. It was determined by DLS and AFM that two different diameter nanospheres had been obtained.

Simple route for synthesis of H‐shaped copolymers

AbstractThe H‐shaped copolymers, [poly(L‐lactide)]2polystyrene [poly(L‐lactide)]2, [(PLLA)2PSt(PLLA)2] have been synthesized by combination of atom transfer radical polymerization (ATRP) with cationic ring‐opening polymerization (CROP). The first step of the synthesis is ATRP of St using α,α′‐dibromo‐p‐xylene/CuBr/2,2′‐bipyridine as initiating system, and then the PSt with two bromine groups at both chain ends (Br–PSt–Br) were transformed to four terminal hydroxyl groups via the reaction of Br–PSt–Br with diethanolamine in N,N‐dimethylformamide. The H‐shaped copolymers were produced by CROP of LLA, using PSt with four terminal hydroxyl groups as macroinitiator and Sn(Oct)2 as catalyst. The copolymers obtained were characterized by 1H NMR spectroscopy and gel permeation chromatography. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2794–2801, 2006

Synthesis of liquid crystalline–amorphous block copolymers by combination of CFRP and ATRP mechanisms

AbstractBlock copolymers of liquid crystalline 6‐(4‐cyanobiphenyl‐4′‐oxy) hexyl acrylate (LC6) and styrene (St) were obtained by the combination of two different free‐radical polymerization mechanisms namely conventional free‐radical polymerization (CFRP) and atom transfer radical polymerization (ATRP). In the first part, thermosensitive azo alkyl halide, difunctional initiator (AI), was prepared and then used for CFRP of LC6 monomer. The obtained bromine‐ended difunctional liquid crystalline polymers (PLC6) were used as initiators in ATRP of St, in bulk in conjunction with CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) as catalyst. In the second part, AI was firstly polymerized by CFRP in the presence of St and then the obtained difunctional bromine ended polystyrenes (PSt) were used as initiators in ATRP of LC6 in diphenyl ether solvent in conjuction with CuBr/PMDETA. The spectral, thermal, and optical measurements confirmed a fully controlled living polymerization, which results in formation of ABA‐type block copolymers with very narrow polydispersities. In both cases, blocks of the different chemical composition were segregated in the solid and melt phases. The mesophase transition temperatures of the liquid crystalline block were found to be very similar to those of the corresponding homopolymers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006

Synthesis of diblock copolymer poly(10-hydroxydecanoic acid)/polystyrene by combining enzymatic condensation polymerization and ATRP

The diblock copolymers poly(10-hydroxydecanoic acid)-block-polystyrene (PHDA-b-PSt) were synthesized by combining enzymatic condensation polymerization of 10-hydroxydecanoic acid (HDA) and atom transfer radical polymerization (ATRP) of styrene (St). PHDA was firstly obtained via enzymatic condensation polymerization catalyzed by Novozyme-435. Subsequently one end of poly(10-hydroxydecanoic acid) (PHDA) chains was modified by reaction with α-bromopropionyl bromide and the other was protected by chlorotrimethylsilane (TMSCL), respectively, the resulting monofunctional macroinitiator was used in the ATRP of St using CuCl/2,2′-bipyridine (bpy) as the catalyst system to afford the diblock copolymers including biodegradable PHDA blocks and well-defined PSt blocks.

Synthesis and characterization of poly(n‐butyl methacrylate)‐b‐polystyrene diblock copolymers by atom transfer radical emulsion polymerization

AbstractPoly(n‐butyl methacrylate) (PBMA)‐b‐polystyrene (PSt) diblock copolymers were synthesized by emulsion atom transfer radical polymerization (ATRP). PBMA macroinitiators that contained alkyl bromide end groups were obtained by the emulsion ATRP of n‐butyl methacrylate with BrCH3CHCOOC2H5 as the initiator; these were used to initiate the ATRP of styrene (St). The latter procedure was carried out at 85°C with CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine as the catalyst and polyoxyethylene(23) lauryl ether as the surfactant. With this technique, PBMA‐b‐PSt diblock copolymers were synthesized. The polymerization was nearly controlled; the ATRP of St from the macroinitiators showed linear increases in number‐average molecular weight with conversion. The block copolymers were characterized with IR spectroscopy, 1H‐NMR, and differential scanning calorimetry. The effects of the molecular weight of the macroinitiators, macroinitiator concentration, catalyst concentration, surfactant concentration, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP are also reported. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2123–2129, 2005

Synthesis and characterization of PBMA-b-PSt-b-PBMA triblock copolymers by atom transfer radical emulsion polymerization

Poly(n-butyl methacrylate)-b-polystyrene-b-poly(n-butyl methacrylate) (PBMA-b-PSt-b-PBMA) triblock copolymers were successfully synthesized by emulsion atom transfer radical polymerization (ATRP). Difunctional polystyrene (PSt) macroinitiators that contained alkyl chloride end-groups were prepared by ATRP of styrene (St) with CCl4 as initiator and were used to initiate the ATRP of butyl methacrylate (BMA). The latter procedure was carried out at 85°C with CuCl/4,4-di (5-nonyl)-2,2- bipyridine (dNbpy) as catalyst and polyoxyethylene (23) lauryl ether (Brij35) as surfactant. Using this technique, triblock copolymers consisting of a PSt center block and PBMA terminal blocks were synthesized. The polymerization was nearly controlled, ATRP of St from those macroinitiators showed linear increases in the number average molecular weight (Mn) with conversion. The block copolymers were characterized with infrared (IR) spectroscopy, hydrogen-1 nuclear magnetic resonance (1HNMR), and differential scanning calorimetry (DSC). The effects of the molecular weight of macroinitiators, concentration of macroinitiator, catalyst, emulsion, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP were also reported

Synthesis of block copolymers from PDMS macroinitiators

AbstractThe synthesis of polystyrene‐b‐polydimethylsiloxane‐b‐polystyrene (PSt‐b‐PDMS‐b‐PSt) copolymers is described. Commercially available difunctional PDMS containing vinylsilyl terminal species was reacted with hydrogen bromide resulting in the PDMS macroinitiators. The terminal alkyl bromide groups were then used as initiators for atom transfer radical polymerization (ATRP) to produce block copolymers. Using this technique, triblock copolymers consisting of a PDMS centre block and polystyrene terminal blocks were synthesized. ATRP of St from those macroinitiators showed linear increases in Mn with conversion, demonstrating the effectiveness of ATRP to synthesize a variety of inorganic/organic polymer hybrids. Copyright © 2004 Society of Chemical Industry

Synthesis and characterization of Pst‐b‐PDMS‐b‐PSt copolymers by atom transfer radical polymerization

AbstractPolystyrene‐b‐poly(dimethylsiloxane)‐b‐polystyrene (Pst‐b‐PDMS‐b‐PSt) triblock copolymers were synthesized by atom transfer radical polymerization (ATRP). Commercially available difunctional PDMS containing vinylsilyl terminal species was reacted with hydrogen bromide, resulting in the PDMS macroinitiators for the ATRP of styrene (St). The latter procedure was carried out at 130°C in a phenyl ether solution with CuCl and 4, 4′‐di (5‐nonyl)‐2,2′‐bipyridine (dNbpy) as the catalyzing system. By using this technique, triblock copolymers consisting of a PDMS center block and polystyrene terminal blocks were synthesized. The polymerization was controllable; ATRP of St from those macroinitiators showed linear increases in Mn with conversion. The block copolymers were characterized with IR and 1H‐NMR. The effects of molecular weight of macroinitiators, macroinitiator concentration, catalyst concentration, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3764–3770, 2004

Functionalization of Single-Walled Carbon Nanotubes with Polystyrene via Grafting to and Grafting from Methods

Single-walled carbon nanotubes (SWNT) were functionalized with polystyrene (PSt) by grafting to and grafting from methods. PSt-N3 with designed molecular weight and narrow molecular weight distribution was synthesized by atom transfer radical polymerization (ATRP) of styrene (St) followed by end group transformation and then added to SWNT. The grafting from functionalization was achieved by ATRP of St using 2-bromopropionate groups immobilized SWNT as initiator. Methyl 2-bromopropionate (MBP) was added as free initiator to control the chain propagation on SWNT during the polymerization. Raman and near-IR spectra show that PSt was covalently attached to the sidewalls of SWNT by the grafting to approach, and the degree of functionalization was about 1 in 48 SWNT carbon atoms as determined by thermogravimetric analyses (TGA). In the grafting from approach, size exclusion chromatography (SEC) results show that the molecular weight of free St increased linearly with St conversion, and the PSt cleaved from the ...

Synthesis of poly(4-vinylpyridine) and block copoly (4-vinylpyridine–b-styrene) by atom transfer radical polymerization using 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazamacrocyclotetradecane as ligand

Poly(4-vinylpyridine) (P4VP) and block copolymer, poly(4-vinylpyridine–b-styrene) (P4VP-b-PSt) were prepared by atom transfer radical polymerization (ATRP) using 1-phenylethyl chloride as initiator, CuCl and 5,5,7,12,12,14–hexamethyl-1,4,8,11-tetraazamacrocyclotetradecane (Me 6[14]aneN 4) as catalyst and ligand. The polymerization of 4VP was carried out in 2-propanol at 40 °C. GPC and NMR studies show that the plot of ln([4VP] 0/[4VP]) against the reaction time is linear, and the molecular weight of the resulting P4VP increased linearly with the conversion. Within 3 h, the conversion can reach almost 90%. P4VP-b-PSt amphiphilic block copolymer with low polydispersity index ( M w/ M n ≈ 1.2) is also obtained by ATRP of St in DMF at 110 °C using P4VP–Cl as macroinitiator, CuCl/ Me 6[14]aneN 4 as catalyst.