Pentamethyldiethylenetriamine Research Articles

Comproportionation versus Disproportionation in the Initiation Step of Cu(0)-Mediated Living Radical Polymerization

We present a study of the initiation step in copper(0)-mediated atom transfer radical polymerization (also known as SET-LRP or SARA ATRP), in which a nitroxide free radical, N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)] nitroxide (SG1), is used to trap radicals derived from ethyl 2-bromoisobutyrate (EBiB), copper metal and pentamethyl diethylene triamine (PMDETA) ligand. A kinetic model was developed relating the rate of conversion of EBiB to the rate constants of activation by copper metal (ka0) and comproportionation of Cu0 and CuII (kcomp). This allowed the determination of these parameters in several solvents, including dimethyl sulfoxide (DMSO), dimethylformamide (DMF), ethanol (EtOH), and acetonitrile (MeCN), in which significant levels of comproportionation were observed, leading to autoacceleration of the reaction. A similar treatment of copper-mediated polymerization kinetics predicts 1/2 order dependence on initiator concentration and copper surface area, in accordance with previously...

Acrylic AB and ABA Block Copolymers Based on Poly(2-ethylhexyl acrylate) (PEHA) and Poly(methyl methacrylate) (PMMA) via ATRP

Acrylic block copolymers have several advantages over conventional styrenic block copolymers, because of the presence of a saturated backbone and polar pendant groups. This investigation reports the preparation and characterization of di- and triblock copolymers (AB and ABA types) of 2-ethylhexyl acrylate (EHA) and methyl methacrylate (MMA) via atom transfer radical polymerization (ATRP). A series of block copolymers, PEHA-block-PMMA(AB diblock) and PMMA-block-PEHA-block-PMMA(ABA triblock) were prepared via ATRP at 90 °C using CuBr as catalyst in combination with N,N,N',N″,N″-pentamethyl diethylenetriamine (PMDETA) as ligand and acetone as additive. The chemical structure of the macroinitiators and molar composition of block copolymers were characterized by (1)H NMR analysis, and molecular weights of the polymers were analyzed by GPC analysis. DSC analysis showed two glass transition temperatures (T(g)), indicating formation of two domains, which was corroborated by AFM analysis. Small-angle X-ray scattering (SAXS) analysis of AB and ABA block copolymers showed scattering behavior inside the measuring limits indicating nanophase separation. However, SAXS pattern of AB diblock copolymers indicated general phase separation only, whereas for ABA triblock copolymer an ordered or mixed morphology could be deduced, which is assumed to be the reason for the better mechanical properties achieved with ABA block copolymers than with the AB analogues.

Synthesis and Characterization of All Acrylic Block Copolymer/Clay Nanocomposites Prepared via Surface Initiated Atom Transfer Radical Polymerization (SI-ATRP)

Surface initiated polymerization (SIP) is an emerging powerful tool to modify and tailor the surface properties of nanoparticles. Among different methods of SIP, surface initiated atom transfer radical polymerization (SI-ATRP) has several strategic advantages over other methods of polymerizations. This investigation reports the preparation and characterization of poly(2-ethylhexyl acrylate) (PEHA)/clay nanocomposite from nanoclay surface via SI-ATRP and poly(2-ethylhexyl acrylate)-block-poly(methyl methacrylate) (PEHA-b-PMMA)/clay nanocomposite via conventional ATRP. To carry out SI-ATRP, the nanoclay (Cloisite Na+) surface was first modified by incorporating an ATRP initiator (2-bromopropionyl bromide) to nanoclay surface via a grafting reaction. The prepared bromo-functionalized nanoclay (Clay–Br) was then used to carry out SI-ATRP of 2-ethylhexyl acrylate (EHA) at 90 °C using CuBr as catalyst in combination with N, N, N′, N″, N″- pentamethyl diethylenetriamine (PMDETA) as the ligand. The macroinitiator...

Synthesis, Structural Elucidation, and Diffusion-Ordered NMR Studies of Homoleptic Alkyllithium Magnesiates: Donor-Controlled Structural Variations in Mixed-Metal Chemistry

This paper presents the synthesis and characterization of new homoleptic lithium magnesiate reagents incorporating the silyl-substituted alkyl ligand CH2SiMe3 in the presence of a variety of Lewis base donors, namely tetrahydrofuran (THF), 1,4-dioxane, N,N,N′,N′-tetramethylethylenediamine (TMEDA), and N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA). The constitution of these bimetallic compounds has been assessed in both the solid state and solution using a combination of X-ray crystallographic studies and multinuclear NMR spectroscopy, including 1H diffusion-ordered (1H-DOSY) NMR experiments. These studies highlight the major role played by the donor molecule in controlling the structure of the complexes as well as the wide structural diversity available for these mixed-metal species ranging from discrete molecules, as found for [(PMDETA)LiMg(CH2SiMe3)3] (6), to more complex supramolecular arrangements, as in the 1D-polymeric chain [{(THF)LiMg(CH2SiMe3)3}∞] (2) or in the stoichiometrically distinct d...

Synthesis of double hydrophilic poly(ethylene oxide)‐b‐poly(2‐hydroxyethyl acrylate) by single‐electron transfer–living radical polymerization

AbstractIn this study, the polymerization of (2‐hydroxyethyl) acrylate (HEA), in polar media, using Cu(0)‐mediated radical polymerization also called single‐electron transfer–living radical polymerization (SET‐LRP) is reported. The kinetics aspects of both the homopolymerization and the copolymerization from a poly(ethylene oxide) (PEO) macroinitiator were analyzed by 1H NMR. The effects of both the ligand and the solvent were studied. The polymerization was shown to reach very high monomer conversions and to proceed in a well‐controlled fashion in the presence of tris[2‐(dimethylamino)ethyl]amine Me6‐TREN and N, N,N′, N″, N″‐pentamethyldiethylenetriamine (PMDETA) in dimethylsulfoxide (DMSO). SET‐LRP of HEA was also led in water, and it was shown to be faster than in DMSO. In pure water, Me6‐TREN allowed a better control over the molar masses and polydispersity indices than PMDETA and TREN. Double hydrophilic PEO‐b‐PHEA block copolymers, exhibiting various PHEA block lengths up to 100 HEA units, were synthesized, in the same manner, from a bromide‐terminated PEO macroinitiator. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Precisely controlled copper(0)‐catalyzed one‐pot reaction: Concurrent living radical polymerization and click chemistry

AbstractCopper(0)‐catalyzed one‐pot reaction combining living radical polymerization and “click chemistry” was investigated. By precisely tuning reaction time, three novel well‐defined polymers with different degree of carboxyl substitution, poly(propargyl methacrylate) (PPgMA), poly(1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate) (PCTMMA), and poly(1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate‐co‐propargyl methacrylate) (PCTMMA‐co‐PPgMA) were selectively obtained via Cu(0) powder/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) cocatalyzed LRP and click chemistry. In addition, gel permeation chromatography and 1H NMR analysis in conjunction with FTIR spectroscopy elucidate that one‐pot process undergoes three steps due to a pronounced rate enhancement of click reaction: (1) generating new monomer, 1‐(4‐carboxyphenyl)‐[1,2,3]triazol‐4‐methyl methacrylate (CTMMA); (2) copolymerization of two monomers (CTMMA and PgMA); (3) building homopolymer PCTMMA. Surprisingly, in contrast to typical Cu(I)‐catalyzed atom transfer radical polymerization (ATRP), copper(0)‐catalyzed one‐pot reaction showed high carboxylic acid group tolerance. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Recovery of Wilkinson's catalyst from polymer based matrix using carbon dioxide expanded methanol

Carbon dioxide-expanded methanol (CXM) is for the first time employed to recover Wilkinson's catalyst from the matrix of hydrogenated nitrile butadiene rubber (HNBR) using the chelating agent N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA). The effects of temperature and pressure on the extraction performance were carefully investigated over the temperature range of 40–100 °C and the pressure range of 20–20 MPa. Increasing temperature effectively increased the extraction rate and became less influential when temperature is above 80 °C. Increasing pressure over the different pressure ranges at 80 °C impacted the extraction rate differently. 6 MPa was considered as the optimal pressure at 80 °C. The rhodium residue was reduced from 700 to 222 ppm by a 5 h extraction at 6 MPa and 80 °C. An extraction mechanism was illustrated for interpreting the present extraction system and guiding the future work. This study establishes a technology platform for separating the expensive catalyst from the polymer matrix, using “green” CO2-expanded liquids.

Development of a green separation technique for recovery of Wilkinson's catalysts from bulk hydrogenated nitrile butadiene rubber

CO2-expanded water (CXW), CO2-expanded methanol (CXM), and CO2-expanded ethanol (CXE) were investigated with respect to their performance for the removal of Wilkinson's catalyst from HNBR with assistance of various chelating agents including ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetraacetic acid disodium salt (EDTA-Na2), diethylenetriamine (DETA), N,N,N′,N′-tetramethylethylenediamine (TMEDA), and N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA). The performance of each extraction system consisting of a CXL and a chelating agent was carefully evaluated. CXM and PMDETA constitute the optimal extraction system. The reactions involved in this system were analyzed to identify the challenges for successful extraction. The extraction rates were measured as a function of temperature and pressure, respectively. 80°C and 6MPa were considered as the most favourable conditions. In addition, the effect of the HNBR sample thickness on the extraction performance was examined. Thinner samples showed advantages in promoting the extraction rate. This green separation technique was verified with a residue containing only 59ppm rhodium after a sequential operation at 80°C and 6MPa.

Preparation of poly(N-isopropylacrylamide) brush grafted silica particles via surface-initiated atom transfer radical polymerization used for aqueous chromatography

Thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) brushes were densely grafted onto silica surface via surface-initiated atom transfer radical polymerization (SI-ATRP). The grafting reaction started from the surfaces of 2-bromoisobutyratefunctionalized silica particles in 2-propanol aqueous solution at ambient temperature using CuCl/CuCl2/N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA) as the catalytic system. Based on thermogravimetric analysis (TGA) results, the grafting amount and grafting density of PNIPAM chains on the surface of silica were calculated to be 1.29 mg/ m2 and 0.0215 chains/nm2, respectively. The gel permeation chromatography (GPC) result showed the relatively narrow molecular weight distribution (Mw/Mn= 1.21) of the grafted PNIPAAm. The modified silica particles were applied as high-performance liquid chromatography (HPLC) packing materials to successfully separate three aromatic compounds using water as mobile phase by changing column temperature. Temperature-dependent hydrophilic/hydrophobic property alteration of PNIPAAm brushes grafted on silica particles was determined with chromatographic interaction between stationary phase and analytes. Retention time was prolonged and resolution was improved with increasing temperature. Baseline separation with high resolution at relatively low temperatures was observed, demonstrating dense PNIPAAm brushes were grafted on silica surfaces.

Synthesis and characterization of polylactide–poly(methyl methacrylate) copolymer by combining of ROP and AGET ATRP

Block copolymers of polylactide (PLA) and poly(methyl methacrylate) (PLA–PMMA) were synthesized by the combination of ring-opening polymerization (ROP) and activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP), where PLA was prepared as macroinitiator with active bromo end group (PLA–Br). Tin octoate (Sn(oct)2) and benzyl alcohol were applied as the initiation system for ROP of lactide. During AGET ATRP, copper (II) chloride (CuCl2) with N,N,N′,N″,N″-pentamethyl-diethylenetriamine (PMDETA) was used as the catalyst system including Sn(oct)2 as reducing agent. At the feed ratio [PLA–Br]/[CuCl2]/[PMDETA]/[Sn(oct)2]/[MMA] of 1/1/9.6/0.45/100, the mole fraction of the PMMA block was 0.6 as determined by 1H NMR. Thermal stability of PLA was enhanced by incorporating of PMMA as block copolymers. In addition, blend between of PLA and PLA–PMMA copolymer was investigated and 5phr of PLA–PMMA showed optimum condition to decrease in Young's modulus and increase in impact strength.

A Route to Modify Polymeric Pigment Dispersants with Polysiloxanes by Atom Transfer Radical Polymerization

A novel approach to modify polymeric pigment dispersants with polysiloxanes was developed based on the sequential atom transfer radical polymerization (ATRP) of styrene (St) and tert-butyl acrylate (tBA), using multifunctional α-bromoisobutyryl-containing poly (dimethylsiloxane) (PDMS-Brm) as the macroinitiators and CuBr/N,N,N,N,N- pentamethyldiethylenetriamine (PMDETA) as the catalyst system. The PDMS-Brm macroinitiators were obtained from the sequential hydrosilylation of commercially available methyl polysiloxanes containing SiH groups with allyl alcohol and then α-bromoisobutyryl bromide. And then, a series of well-defined comb-like graft copolymers with a PDMS backbone and several polystyrene-block-poly (tert-butyl acrylate) (PS-b-PtBA) side-chains were synthesized via ATRP. After hydrolyzing the tert-butyl groups, the comb-like copolymers may serve as multifunctional dispersing agents in the pigment printing.

The fabrication and self-flocculation effect of hybrid TiO2 nanoparticles grafted with poly(N-isopropylacrylamide) at ambient temperature via surface-initiated atom transfer radical polymerization

This article reports on the fabrication of hybrid titanium dioxide (TiO2) nanoparticles grafted with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and their self-flocculation effect caused by the thermal phase transition and entanglement behavior of PNIPAM. Surface-initiated atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAM) was conducted rapidly (within a few minutes) in aqueous solution at ambient temperature by using CuBr/N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA) as the catalysts and started from the surface of TiO2 nanoparticles derivatized with ATRP initiators. Without purifying the inhibitor, the grafted PNIPAM gives low molecular weights (Mn < 3000) and a narrow molecular weight distribution (PDI < 1.1) determined by GPC detection, which gives the hybrid TiO2–PNIPAM both a self-flocculation effect with rapid response to temperature, and a temperature-controlled switching effect of the degradation of Rhodamine B in solution. Moreover, the hybrid TiO2–PNIPAM exhibits a particular dispersion effect at ambient temperature in aqueous solution caused by the hydrophilicity and the entanglement interaction of the grafted PNIPAM. These effects for hybrid TiO2–PNIPAM provide a new way to re-use TiO2 nanoparticles for pollutant degradation systems and to avoid secondary pollution effectively due to the thermal phase transition and entanglement behavior.

Synthesis and structural elucidation of a rare example of a tris(amido) potassium magnesiate

An equimolar quantity of benzylpotassium and di-n-butylmagnesium were combined with three molar equivalents of diphenylamine in a solvent medium which consisted on THF, hexane and N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA). This mixture produces a rare example of a potassium tris(amido) magnesiate, namely (PMDETA)·K(μ-NPh2)Mg(THF)(NPh2)21. Complex 1 was characterized by X-ray crystallography and 1H and 13C NMR spectroscopy. The solid state structure of 1 (particularly the metals′ co-ordination spheres) differs considerably from that of previously characterized potassium magnesiates, presumably due to the less sterically demanding nature of the amido ligand employed in this study. The magnesium center is four-coordinate (usually three-coordinate in such ate systems) and as well as binding to three amido ligands, is coordinated to a THF molecule. Turning to the potassium center, it is bound to three N centers from the triamine PMDETA, only one amido group, and its coordination sphere is completed by a series of aryl-π contacts. The 1H NMR solution studies in C6D6 appear to show that the complex does not stay intact in arene but likely forms a solvent-separated species such as [K(C6D6)x]+[(THF)Mg(NPh2)3−].

Atom transfer radical polymerization of methylmethacrylate and styrene initiated by 3,5-bis(perfluorobenzyloxy)benzyl 2-bromopropanoate

The synthesis of polymethylmethacrylate (pMMA) and polystyrene (pSt) were realized with newly synthesized initiator, 3,5-bis(perfluorobenzyloxy)benzyl 2-bromopropanoate (FBr) in the presence of copper bromide (CuBr) and N,N,N′,N″,N″-pentamethyl-diethylenetriamine (PMDETA) by using atom transfer radical polymerization (ATRP). The perfluorinated aromatic group containing initiator was prepared by esterification of the (3,5-bis[(perfluorobenzyl)oxy]-phenyl alcohol. Both initiator and polymers were characterized by 1H-NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. The ATRP was supported by an increase in the molecular weight of the forming polymers and also by their monomodal molecular weight distribution. Contact angle measurements of water and ethylene glycol on films of synthesized polymers indicated higher degree of hydrophobicity than that of pure pMMA and pure pSt. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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.

Synthesis of xylan-graft-poly(l-lactide) copolymers via click chemistry and their thermal properties

Abstract Di-O-(6-azidohexanoyl)-xylan-graft-poly( l -lactide)s (XylC6N3-g-PLLAs) were prepared by grafting propargyl-terminated poly( l -lactide) onto di-O-(6-azidohexanoyl)-xylan (XylC6N3) via click chemistry. Di-O-(6-azidohexanoyl)-xylan (XylC6N3) was prepared via two steps from xylan extracted from eucalyptus kraft pulp with aqueous sodium hydroxide solution. Propargyl-terminated poly( l -lactide)s (PLLA) with three different molecular weights were synthesized via ring-opening polymerization of l -lactide using propargyl alcohol as initiator and tin (II) octanoate (Sn(Oct)2) as catalyst. XylC6N3 and propargyl-terminated PLLAs were treated with N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA) and copper(I) bromide, and the graft copolymers XylC6N3-g-PLLAs were obtained. DSC measurements revealed that the glass transition temperatures (Tg) of the copolymers decreased compared to that of XylC6N3, suggesting that the grafted PLLA side-chains act as an internal plasticizer for xylan. TGA measurements revealed that XylC6N3-g-PLLAs had higher decomposition temperatures than those of XylC6N3 or PLLA, and that the decomposition temperatures of the copolymers increased with decrease in the number of PLLA side-chains grafted to the xylan main-chain.

Synthesis of cyclohexanone formaldehyde resin‐methylmethacrylate block‐graft copolymers via ATRP

AbstractWell defined block‐graft copolymers of cyclohexanone‐formaldehyde resin (CFR) and methylmethacrylate (MMA) were prepared via atom transfer radical polymerization (ATRP). In the first step, cyclohexanone formaldehyde resin (CFR) containing hydroxyl groups were modified with 2‐bromopropionyl bromide. Resulting multifunctional macroinitiator was used in the ATRP of MMA using copper bromide (CuBr) and N,N,N′,N″,N″‐pentamethyl‐diethylenetriamine (PMDETA) as catalyst system at 90°C. The chemical composition and structure of the copolymers were characterized by nuclear magnetic resonance (1H‐NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and molecular weight measurement. Molecular weight distributions of the CFR graft copolymers were measured by gel permeation chromatography (GPC). Mn values up to 19,000 associated with narrow molecular weight distributions (polydispersity index (PDI) &lt; 1.6) were obtained with conversions up to 49%. Coating properties of synthesized graft copolymers such as adhesion and gloss values were measured. They exhibited good adhesion properties on Plexiglas substrate. The thermal behaviors of all polymers were conducted using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

The characterisation of the interfacial chemistry of adhesion of rigid polyurethane foam to aluminium

The interfacial interactions between a rigid polyurethane foam (RPUF) and aluminium have been studied to understand the mechanisms of adhesion. Three different blowing systems are used in the production of the foam: chemical blowing, physical blowing and a mix of chemical and physical blowing systems. In addition an unfoamed system has been examined for comparison of the catalysts behaviour with and without blowing agents and the surfactant. Peeled failure surfaces have been examined by X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (ToF–SIMS). To examine the intact interfacial regions of the RPUFs cured against aluminium, samples have been sectioned by microtomy. The failure surfaces of the aluminium sides exhibit relatively clean aluminium surfaces with RPUF residues observed for all three foamed systems; such thin RPUF layers (ca. 1 nm) indicate good adhesion (and a cohesive failure) between foam and substrate and that the interfacial adhesion is higher than the cohesive strength of the foam. The unfoamed system behaves in a similar manner but has a higher peel strength. A fragment indicative of covalent bond formation between isocyanate and aluminium (nominal mass at 102 u: AlCHNO3 −) is observed on the failure surface of aluminium side, where RPUF/aluminium interface region is present, for all foams. The catalyst used in these formulations, pentamethyldiethylenetriamine (PMDETA), is concentrated at the interface area. Whilst examination of the sectioned specimens shows that the silicone surfactant is concentrated within the cell area fulfilling its role on cell formation and stabilisation, and is not segregated at the RPUF/aluminium interface.

Synthesis and fluorescence properties of polystyrene via atom transfer radical polymerization using a coumarin derivate as initiator

Well-defined polystyrene was successfully synthesized via atom transfer radical polymerization, using a novel coumarin derivate, 2-bromo-2-methyl-propionic acid 4-methyl-2-oxo-2H-chromen-7-yl ester (BMP), synthesized in our lab as an initiator, and CuBr/N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA) as the catalyst at 110 °C. The kinetics of the polymerization was studied in detail. The fluorescence properties of the resultant polystyrenes were studied in N,N-dimethylformamide (DMF). It is very interesting that the adding of Fe3+ has significant effect on the fluorescence intensities, which decreased with increasing the concentration of iron in solutions. The obtained polystyrenes can be used as fluorescent probe molecules for Fe3+.

Synthesis of Eight‐shaped Poly(ethylene oxide) by the Combination of Glaser Coupling with Ring‐opening Polymerization

The eight-shaped poly(ethylene oxide) (PEO) is synthesized by a combination of Glaser coupling with ring-opening polymerization (ROP). Firstly, the star-shaped (PEO-OH)(4) is synthesized by ROP of ethylene oxide (EO) using pentaerythritol as an initiator and diphenylmethyl potassium (DPMK) as a deprotonated agent, and then the alkyne group is introduced onto the PEO arm-end to give (PEO-Alkyne)(4) in a NaH/tetrahydrofuran (THF) system. The intramolecular cyclization is carried out by a Glaser coupling reaction in a pyridine/CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) system at room temperature in an air atmosphere, and eight-shaped PEO was formed with high efficiency (almost 100%). The target polymers and intermediates were well characterized by SEC, MALDI-TOF MS, (1)H NMR and FT-IR in detail.