Ethoxyethyl Group Research Articles

Wettability and Surface Tension of Imidazolium, Ammonium, and Phosphonium Bis(fluorosulfonyl)amide Ionic Liquids: Comparison between Pentyl, Ethoxyethyl, and Ethylthioethyl Groups.

This study particularly compares the surface tensions and contact angles for molten bis(fluorosulfonyl)amide salts of imidazolium, ammonium, and phosphonium cations with the pentyl, ethoxyethyl, or ethylthioethyl group. The examined substrate plates for contact angle measurements include silicate glass, platinum, copper, graphene, and polytetrafluoroethylene (PTFE). In addition, quantum chemistry calculations were performed to obtain the optimized structures of the cations and anions of the ionic liquids (ILs) that were studied here along with some typical anions and their dipole moments, mean polarizabilities, and charge distributions. All ILs showed the same order of contact angles with respect to the substrates: PTFE > graphene ≈ copper ≈ platinum > silicate glass. By comparing the three functional groups, i.e., pentyl, ethoxyethyl, and ethylthioethyl, the ILs with the ethylthioethyl group featured a higher work of adhesion than the respective ILs with the pentyl or ethoxyethyl group. The values of the surface tensions of the ILs followed the same trend for the three functional groups. Based on the Fowkes theory, it was found that the larger surface tensions of the ILs with the ethylthioethyl group compared with pentyl and ethoxyethyl groups were because of the increase in both dispersive and nondispersive components. The quantum chemistry calculations of the ions showed a larger dipole moment and mean polarizability for the cations with the ethylthioethyl group as compared with the pentyl and ethoxyethyl groups. This is consistent with the analysis results of the surface tensions based on the Fowkes theory. By comparing other anions, the dispersive component of the surface tension of the ILs with bis(fluorosulfonyl)amide was large, which is attributed to the small dipole moment of the anion.

Linear Amphiphilic Polyglycidol/Poly(ε-caprolactone) Block Copolymers Prepared via “Click” Chemistry-Based Concept

We introduce a “click” chemistry-based concept for the preparation of amphiphilic block copolymers comprising linear polyglycidol (PG). Herein, a new class of linear polyglycidol/poly(e-caprolactone) (PG/PCL) block copolymers of precisely designed macromolecular characteristics and composition was synthesized to demonstrate the convenience of this strategy. Monohydroxyl poly(ethoxyethylglycidyl ether) (PEEGE) precursors were synthesized by ring-opening anionic polymerization of ethoxyethylglycidyl ether (EEGE) and subsequently functionalized with a “clickable” alkyne end group. In parallel, a bifunctional PCL diol was modified to an azide-terminated macroreagent. PG/PCL block copolymers were obtained by “click” coupling reaction of the alkyn- and azide-functional macroreagents in the presence of a CuBr/PMDETA catalytic complex and subsequent cleavage of the protective ethoxyethyl groups of PEEGE. The amphiphilic block copolymers were not directly soluble in water, and defined nano-sized micelles were obta...

Synthesis of twin‐tail tadpole‐shaped (cyclic polystyrene)‐ block‐[linear poly (tert‐butyl acrylate)]2 by combination of glaser coupling reaction with living anionic polymerization and atom transfer radical polymerization

AbstractThe twin‐tail tadpole‐shaped (cyclic polystyrene)‐block‐[linear poly (tert‐butyl acrylate)]2 [(c‐PS)‐b‐(l‐PtBA)2] was synthesized by combination of Glaser coupling reaction with atom transfer radical polymerization (ATRP) and living anionic polymerization (LAP). First, the telechelic PS with an active and an ethoxyethyl‐protected hydroxyl groups at both ends was prepared by LAP of St monomers using lithium naphthalenide as initiator and terminated by 1‐ethoxyethyl glycidyl ether. And the alkyne groups were introduced onto each PS end by selectively reaction of active hydroxy group with propargyl bromide in NaH/tetrahydrofuran (THF) system. Then, the intramolecular cyclization was carried out by Glaser coupling reaction in pyridine/Cu(I)Br system in air atmosphere. Finally, the macroinitiator of c‐PS with two bromine groups at the junction point was synthesized via the cleavage of ethoxyethyl group and the subsequent esterification of the deprotected hydroxyl groups with 2‐bromoisobutyryl bromide. The copolymer of (c‐PS)‐b‐(l‐PtBA)2 was obtained by ATRP of tBA monomers, and the PtBA segment was also hydrolyzed for (cyclic polystyrene)‐block‐(linear polyacrylic acid)2 [(c‐PS)‐b‐(l‐PAA)2]. The target copolymers and all intermediates were well characterized by GPC, MALDI‐TOF MS, and 1H NMR in detail. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Water-soluble anionic fluorophores from truxene

Two new water-soluble fluorophores are synthesized from truxene and ester-substituted aryl acetylenes. The truxene core is decorated by 2-(2′-methoxy)ethoxyethyl groups to enhance the hydrophilicity of these fluorophores as well as to prevent the aggregation by π-stacking in aqueous media. The conjugated structures are assembled by iodination of the truxene core and subsequent Sonogashira coupling with aryl acetylenes. Upon the hydrolysis of the ester groups, water-soluble fluorophores are obtained in good to excellent yield (30–71% for 3 steps). A photophysical investigation reveals that these compounds exhibit strong fluorescence signals (quantum yield 46–63%) with maximum emission wavelength around 390–400 nm in aqueous phosphate buffer. Preliminary screening on sensing application shows that their fluorescent signals can be selectively quenched by porphyrin-containing metalloproteins.

Synthesis of ABC Star-Shaped Copolymers via a Combination of Controlled Polymerization Techniques

Two kinds of ABC-type miktoarm star copolymers, poly(α-methylstyrene)-poly(ethylene oxide)-poly(ethoxyethyl glycidylether) (PMS-PEO-PEEGE) and poly(α-methylstyrene)-poly(ethylene oxide)-polyglycidol (PMS-PEO-PG), were synthesized via a combination of anionic polymerization with ring-opening polymerization. Firstly, The poly(α-methyl styryl lithium) (PMS－Li+) was capped by EEGE to form the functionalized poly(α-methylstyrene) with both an active ω-hydroxyl group and an ω’-ethoxyethyl-protected hydroxyl group. Secondly, the PMS-b-PEO block copolymers, star(PMS-PEO-PEEGE) and star(PMS-PEO-PG) copolymers were obtained by the ring-opening polymerization of EO and EEGE via the variation of the functional end group, respectively. Finally, the ethoxyethyl group on the PEEGE arm was hydrolyzed. The obtained miktoarm star copolymers and intermediates were characterized by proton nuclear magnetic resonance (1H-NMR) and size exclusion chromatography (SEC).

Synthesis of novel amphiphilic graft copolymers composed of poly(ethylene oxide) as backbone and polylactide as side chains

A well-defined amphiphilic comb-like copolymer of poly(ethylene oxide)(PEO) as main chain and polylactide (PLA) as side chain was successfully prepared via a combination of anionic polymerization and coordination-insertion ring-opening polymerization. The anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE) was carried out using potassium 2-(2-methoxyethoxy)ethoxide as initiator, and then ethoxyethyl groups of EEGE units of the copolymers obtained were removed by hydrolysis. Two copolymers of methoxypoly(ethylene oxide-co-glycidol) [mpoly(EO-co-Gly)] were formed with multiple hydroxyl sites (the molar ratio values of Gly to EO in copolymers: 1/10.6 and 1/5.2; Mn: 10,100 and 5,020 respectively), and them were used further to initiate the ring-opening polymerization of lactide in the presence of stannous octoate, and a well-defined comb-like copolymer of PEO as main chain and PLA as side chain was obtained. The intermediate and final products of PEO-g-PLA were characterized by GPC and NMR in detail.

Physicochemical Properties of New Dicationic Ether-Functionalized Low Melting Point Ammonium Salts

Eleven new and one previously known but insufficiently characterized dicationic quaternary ammonium (QA) salts were synthesized and characterized. They contain an ethoxy ethyl group either in a side chain and/or as spacer of the diammonium cation and have bromide, hexafluorophosphate (PF6–), bis(trifluoromethanesulfonyl)imide (TFSI), or trifluoromethanesulfonate (TFMS) as an anion. 1H and 13C techniques, mass spectrometry, and elemental analysis together with X-ray diffraction and thermoanalytical methods were used for their characterization both in the liquid and solid state. In addition, residual water content and viscosity measurements were made for the two room temperature ionic liquids (RTILs). Capillary electrophoresis was used to measure the conductivity of the RTILs. Crystal structures of four compounds were determined by X-ray single crystal diffraction, and powder diffraction was used to study the crystallinity of the solid salts and to compare the structural similarities between the single crystals and the microcrystalline bulk form. Two of the TFSI salts were liquids below room temperature, having liquid ranges of ~380 and 350°C, respectively, and seven out of 12 salts melted below 100°C. In addition, both the TFSI and PF6 salts exhibited high thermal stabilities decomposing at about, or above 300°C. Both RTILs presented moderate viscosities at elevated temperatures. The determined physicochemical properties of the reported ILs suggest their applicability for various applications such as heat transfer fluids, high temperature synthesis, and lubricants.

Anomalous behavior of poly(ethylene glycol)p-tert-octylphenyl ether (Triton X-100) in the water-cyclohexane system

The distribution of Triton X-100 nonionic surfactant in the water-cyclohexane system was investigated by the scintillating phase method. It was shown that an increase in the distribution coefficient as the volume ratio between the aqueous and organic phases grew was explained by the presence in Triton X-100 of homologues with different numbers of ethoxyethyl groups and with the distribution coefficients between the phases different by many times. For the real composition of Triton X-100, distribution coefficients of components of the surfactant were estimated, and the behavior of the surfactant in the system under consideration was simulated; the results were in close agreement with the experimental data.

Preparation of H‐shaped ABCAB terpolymers by atom transfer radical coupling

AbstractH‐shaped ABCAB terpolymers composed of polystyrene (PS) (A), poly(ethylene oxide) (PEO) (B), and poly(tert‐butyl acrylate) (PtBA) (C) were prepared by atom transfer radical coupling reaction using ABC star terpolymers as precursors, CuBr and N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) as catalysts, and nanosize copper as the reducing agent. The synthesis of 3‐miktoarm star terpolymer PS‐PEO‐(PtBA‐Br) involved following steps: (1) the preparation of PS with an active and an ethoxyethyl‐ptotected hydroxyl group at the same end; (2) the preparation of diblock copolymer PS‐b‐PEO with ethoxyethyl‐protected group at the junction point through the ring‐opening polymerization (ROP) of EO; (3) after de‐protection of ethoxyethyl group and further modification of hydroxyl group, tBA was polymerized by atom transfer radical polymerization using PS‐b‐PEO with 2‐bromoisobutyryl functional group as macroinitiator. The H‐shaped terpolymer could be successfully formed by atom transfer radical coupling reaction in the presence of small quantity of styrene, CuBr/PMDETA, and Cu at 90 °C. The copolymers were characterized by SEC, 1H NMR, and FTIR in detail. The optimized coupling temperature is 90 °C. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 59–68, 2009

Synthesis and characterization of well‐defined ABC 3‐Miktoarm star‐shaped terpolymers based on poly(styrene), poly(ethylene oxide), and poly(ϵ‐caprolactone) by combination of the “living” anionic polymerization with the ring‐opening polymerization

AbstractA series of well‐defined ABC 3‐Miktoarm star‐shaped terpolymers [Poly(styrene)‐Poly(ethylene oxide)‐Poly(ε‐caprolactone)](PS‐PEO‐PCL) with different molecular weight was synthesized by combination of the “living” anionic polymerization with the ring‐opening polymerization (ROP) using macro‐initiator strategy. Firstly, the “living” poly(styryl)lithium (PS−Li+) species were capped by 1‐ethoxyethyl glycidyl ether(EEGE) quantitatively and the PS‐EEGE with an active and an ethoxyethyl‐protected hydroxyl group at the same end was obtained. Then, using PS‐EEGE and diphenylmethylpotassium (DPMK) as coinitiator, the diblock copolymers of (PS‐b‐PEO)p with the ethoxyethyl‐protected hydroxyl group at the junction point were achieved by the ROP of EO and the subsequent termination with bromoethane. The diblock copolymers of (PS‐b‐PEO)d with the active hydroxyl group at the junction point were recovered via the cleavage of ethoxyethyl group on (PS‐b‐PEO)p by acidolysis and saponification successively. Finally, the copolymers (PS‐b‐PEO)d served as the macro‐initiator for ROP of ε‐CL in the presence of tin(II)‐bis(2‐ethylhexanoate)(Sn(Oct)2) and the star(PS‐PEO‐PCL) terpolymers were obtained. The target terpolymers and the intermediates were well characterized by 1H‐NMR, MALDI‐TOF MS, FTIR, and SEC. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1136–1150, 2008

Preparation of Star‐Shaped ABC Copolymers of Polystyrene‐Poly(ethylene oxide)‐Polyglycidol Using Ethoxyethyl Glycidyl Ether as the Cap Molecule

AbstractThe 3‐miktoarm star‐shaped ABC copolymers of polystyrene–poly(ethylene oxide)–poly(ethoxyethyl glycidyl ether) (PS‐PEO‐PEEGE) and polystyrene–poly(ethylene oxide)–polyglycidol (PS‐PEO‐PG) with low polydispersity indices (PDI ≤ 1.12) and controlled molecular weight were synthesized by a combination of anionic polymerization with ring‐opening polymerization. The polystyryl lithium (PS−Li+) was capped by EEGE firstly to form the functionalized polystyrene (PSA) with both an active ω‐hydroxyl group and an ω′‐ethoxyethyl‐protected hydroxyl group, and then the PS‐b‐PEO block copolymers, star(PS‐PEO‐PEEGE) and star(PS‐PEO‐PG) copolymers were obtained by the ring‐opening polymerization of EO and EEGE respectively via the variation of the functional end group, and then the hydrolysis of the ethoxyethyl group on the PEEGE arm. The obtained star copolymers and intermediates were characterized by 1H NMR spectroscopy and SEC.magnified image

Water-Soluble Star Brush Copolymer with Four Arms Composed of Poly(ethylene Oxide) as Backbone and Poly(acrylic Acid) as Side Chains

A series of water-soluble star brush copolymers with four arms consisting of poly(ethylene oxide)(PEO) as the backbone and poly(acrylic acid) as side chains with different grafting density were prepared by sequential anionic copolymerization and then atom transfer radical polymerization (ATRP). The anionic ring-opening copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE) was carried out using pentaerythritol and diphenylmethylpotassium (DPMK) as co-initiator, and then ethoxyethyl groups of EEGE units of the copolymers obtained were removed by hydrolysis. The forming four-arm star copolymers of poly(ethylene oxide-co-glycidol) [poly(EO-co-Gly)]4 was esterified by the reaction of pending hydroxyl groups of glycidol units of copolymers with 2-bromoisobutyryl bromide, and the resulting macroinitiators of poly(ethylene oxide-co-2-bromoisobutyryloxyglycidyl ether) [poly(EO-co-BiBGE)]4 were used to initiate the polymerization of t-butyl acrylate by ATRP. Afterward, the tBA ester groups of [poly(EO-co-Gly)-g-PtBA]4 were selectively hydrolyzed by trifluoroacetic acid to obtain the water-soluble [poly(EO-co-Gly)-g-PAA]4. The final product and intermediates were characterized by SEC and NMR in details.

Functionalized micelles from new ABC polyglycidol-poly(ethylene oxide)-poly( d, l-lactide) terpolymers

New ABC type terpolymers of poly(ethoxyethyl glycidyl ether)/poly(ethylene oxide)/poly( d, l-lactide) were obtained by multi-mode anionic polymerization. After successive deprotection of the ethoxyethyl groups from the first block, highly hydroxyl functionalized copolymers of polyglycidol/poly(ethylene oxide)/poly( d, l-lactide) were obtained. These copolymers form elongated ellipsoidal micelles by direct dissolution in water. The micelles consist of a poly( d, l-lactide) core and stabilizing shell of polyglycidol/poly(ethylene oxide). The hydroxyl groups of polyglycidol blocks situated at the micelle surface provide high functionality, which could be engaged in further chemical modification resulting in a potential drug targeting agents. The micellization process of the copolymers in aqueous media was studied by hydrophobic dye solubilization, static and dynamic light scattering, and transmission electron microscopy.

Study of Deprotection Reaction during Exposure in Chemically Amplified Resists for Lithography Sinulation.

Deprotection reactions of chemically amplified resists during exposure are observed by using the in-situ FT-IR with the 248nm light source, and resist profiles are simulated using the activation energy and the prefactor calculated. The resists used in this experiment are poly(p-hydroxystyrene) (PHS) protected by Ethoxyethyl (EOE) group, by tert-Butoxycarbonyl (t-BOC) group and by these heterogeneous protection groups. The activation energy for the EOE resist is much lower than that for the t-BOC resist. The existence of heterogeneous protection groups affect mutually deprotection reactions; the EOE group additions to t-BOC resist reduce the activation energy for the deprotection reaction of t-BOC group. It is confirmed that existences of heterogeneous protection groups affect the formation of resist pattern profile by lithography simulator.

Syntheses and characterizations of three vinyl copolymers containing pendant calix[4]arenes

Three new copolymers containing pendant calix[4]arene units have been synthesized via radical initiated reactions involving a vinylic calix[4]arene monomer with methylacrylate, acrylonitrile, and styrene. The calix[4]arene monomer was locked into tie cone conformation by appending four ethoxyethyl groups to its lower rim. The upper rim of the calix[4]arene monomer, which was the site of polymerization, was monofunctionalized with a modified acrylate ester moiety. A seven atom spacer group was incorporated between the bulky calixarene core and the acrylate moiety in order to minimize steric interactions which proved to impede the polymerization. The copolymers were designed to take advantage of the well-established binding interactions of calixarenes with neutral molecules and ions. The ultimate goal of this project is to develop materials that are suitable for incorporation into chemical sensor devices such as ion-specific electrodes, semipermeable membranes and quartz microbalances.

Theoretical calculations of sensitivity of deprotection reactions for acrylic polymers for 193 nm lithography

The reaction energy of deprotection reactions, density of the reaction site, glass transition temperature, gas permeability, density and relative permittivity of photoresists of poly(TCDA5–RMA3–MAA2) and poly(TCDMACOOR4–TCDMACOOH6) with various protection groups were calculated. The most-enhanced exothermicity was calculated for protection groups containing an ethoxyethyl group as compared to the other protection groups: tetrahydropyranyl, tricyclodecanyl and tert-butyl. For the ethoxyethyl protection groups, a good correlation was found between the experimental sensitivity and the calculated values of the relative permittivity and the glass transition temperature of the polymers. This indicates that calculating these properties of polymers can provide a quick way to identify polymers having a high sensitivity for ArF lithography.

Preparation of (Z) and (E)-9-dodecenyl acetates

The sexual pheromones (Z)-9-dodecenyl acetate (IXa) and (E)-9-dodecenyl acetate (IXb) were synthesized using facile preparation of the acetylenic precursor, 9-decyn-1-ol (IV), from tetrahydrofurfuryl chloride (I). Hydroxyl groups of intermediates in the subsequent steps were protected by the ethoxyethyl group.

Mechanisms for the solvolytic decompositions of nucleoside analogues— I: Acidic hydrolysis of 2-substituted 1-(1-ethoxyethyl)benzimidazoles

A few 2-substituted 1-(1-ethoxyethyl)benzimidazoles have been prepared and the rate constants for their hydrolysis measured at various temperatures and oxonium ion concentrations. The formal kinetics followed and the effect of varying the 2-substitution on the hydrolysis rate suggest that the acid-catalyzed cleavage of these compounds involves a rapid initial protonation of the benzimidazole ring and a subsequent rate-limiting heterolysis of the protonated substrate to form a free nitrogen base and an ocarbenium ion derived from the ethoxyethyl group. The values obtained for the entropy of activation are consistent with the assumed unimolecular nature of the rate-limiting step. The effects of 2-substituents on the acidities of the protonated substrates and their heterolysis rates have been compared. The latter partial reaction has been suggested to be the subject of steric acceleration.

Chemical synthesis of ppGpp

The chemical synthesis of ppGpp (guanosine 3′,5′-dipyrophosphate) is described. The synthesis started from guanosine 3′,5′-diphosphate. The acidlabile ethoxyethyl group was used to protect the 2′-OH functional group. The pyrophosphate linkages were built up simultaneously according to the anionexchange method and the protecting group was removed by dilute aqueous acetic acid. In an analogous manner the isomeric non-natural ppGpp (guanosine 2′,5′-dipyrophosphate) and uridine 2′(3′),5′-dipyrophosphate were synthesized as well.

Conductivities and densities of aqueous solutions of quaternary ammonium iodides containing pentyl and ethoxyethyl groups

Conductivities and densities of aqueous solutions of quaternary ammonium iodides containing pentyl and ethoxyethyl groups