bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfonated poly(bis‐A)‐sulfones as proton exchange membranes for direct methanol fuel cell application
Authors: He Shoulin , Yu Jianjia , Li Cuihua , Fang Jianhua , Xu Jing , Guan Rong 
Published: September 2010

AbstractSulfonated poly(bis‐A)‐sulfone (SPSF) samples were prepared by a mild postsulfonation method using trimethylsilyl chlorosulfonate as sulfonation agent, and their thermal and mechanical properties were evaluated. The serials of SPSF membranes are thermally stable up to 450°C in air. When compared with the poly(bis‐A)‐sulfone membrane, the hydrophilicity and water uptake of the SPSF membranes are enhanced. A microphase‐separated structure comprised of hydrophilic and hydrophobic polymer backbone was observed from atomic force microscopy phase images. The hydrophilic ionic clusters become continuous to form channels when ion exchange capacity (IEC) reached 1.47 mequiv/g. Moreover, the membranes showed very good proton conductivities (20°C, 0.01–0.11 S/cm) and low‐methanol permeability (0.09–3.06 × 10−6 cm2/s), and the methanol diffusion coefficients were lower than that of Nafion112 (1.35 × 10−6 cm2/s) with IEC values from 0.70 to 1.47 mequiv/g. However, the Fenton's reagent test revealed that the membranes exhibited very poor oxidation stability, which is the main defect limiting the application of SPSF for proton exchange membranes. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Interpenetrating polymer network of blocked polyurethane and phenolic resin. I. Synthesis, morphology, and mechanical properties
Authors: Sun Yun‐Yun , Chen Chin‐Hsing 
Published: September 2010

AbstractInterpenetrating polymer networks (IPNs) based on blocked polyurethane (BPU)/phenolic (PF) were prepared using simultaneous polymerization method. The IPN was prepared from BPU prepolymer with m‐xylylenediamine as the chain extender and PF prepolymer using p‐toluene sulfonic acid as a catalyst. From Fourier transform infrared spectra analysis, it was found that the major reactions in the BPU/PF IPN system are the polymerization of BPU/MXDA and the self‐polymerization of PF. It was confirmed from scanning electron micrography that the BPU/PF IPN compatibility of the networks was improved, and the system was heterogeneous and more than one phase existed in the IPN. The tensile properties, flexural properties, impact, and hardness of the prepared IPN were studied. To obtain the best mechanical properties of IPN materials, the filler added in IPN materials has to be investigated. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
One‐step preparation of black polystyrene particles via in situ suspension polymerization
Authors: Yan Juntao , Miao Xiaojie , Zhang Qiaoyun , Cui Xuejun , Li Junfeng , Wang Hongyan 
Published: September 2010

AbstractA facile one‐step technique of preparing black polystyrene (PS) was developed by in situ suspension polymerization in which polymerization of styrene was conducted in the presence of modified carbon black (CB). A series of uniform black PS particles had been synthesized with this method. Morphology and dispersion stability of the various CBs were investigated by both scanning electron microscopy and spectrophotometric analysis. The results of thermogravimetric analysis indicated that the thermal stability of PS was significantly enhanced by introducing modified CB. In addition, the PS synthesized in the absence or presence of modified CB possessed a narrow molecular distribution, as was characterized by gel permeation chromatography. Compared with the conventional mechanical blending technique of PS and CB, our present technique could not only avoid the drawback of poor miscibility between the CB and PS, but also simplify the synthesis technique. Scanning electron microscopy micrographs of the resulting black PS demonstrated that modified CB was well dispersed in the PS matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Solvent effect on the heat of solution and partial molar volume of magnesium perchlorate
Authors: Kiselev V. D. , Bolotov A. V. , Kashaeva H. A. , Shakirova I. , Averyanova A. , Satonin A. , Konovalov A. I. 
Published: September 2010

AbstractFor magnesium perchlorate (MP), the solvent effect on the heat of solution and partial molar volumes (PMV) at 25 °C was studied. Since the complete dissociation of magnesium perchlorate is more difficult to achieve as compared with lithium perchlorate (LP), the concentration dependence of the values of the heat of solution and partial molar volume were noted. Only in highly polar solvents with large donor numbers (DN), such as water, dimethyl sulfoxide, N,N‐dimethyl formamide, and formamide, the differential and integral values of the enthalpies of solution were the same in the range of concentrations studied. In all solvents studied, the values of the heat of solution of MP were highly exothermic and exceed that of LP by more than 30 kcal mol−1. The values of the partial molar volume of MP were changed from 82.3 cm3 mol−1 in formamide to −2.4 cm3 mol−1 in acetone, and correlate linearly with that of LP (R = 0.975). Taking into account the significant change in the properties of molecules in the solvate shell of cation Mg2+, the large increase in the reactivity of reactants, activated by such interaction with Mg2+ cation is expected. Copyright © 2010 John Wiley & Sons, Ltd.
Regioregular poly(3‐alkanoylthiophene): Synthesis and electrochemical, photophysical, charge transport, and photovoltaic properties
Authors: Wang Chao , Kim Felix S. , Ren Guoqiang , Xu Yongqian , Pang Yi , Jenekhe Samson A. , Jia Li 
Published: September 2010

AbstractHead‐to‐tail regioregular poly(3‐heptanoylthiophene) (PHOT) was synthesized by Ni‐catalyzed polycondensation of the 2,2‐dimethyl‐1,3‐propanediol‐protected Grignard monomer followed by deprotection. Cyclic voltammetric (CV) study demonstrates that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of PHOT are 0.5 eV lower in energy than those of the head‐to‐tail poly(3‐hexylthiophene) (HT‐P3HT). Their optical band gaps are essentially the same. Incomplete photoluminescence (PL) quenching was observed in thin films of the 1:1 blend of PHOT and HT‐P3HT. PHOT displayed a glass transition at ∼269 °C and decomposed at ∼300 °C according to differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Wide‐angle X‐ray diffraction (WAXD) study showed that PHOT exists in a not highly ordered state in solid films especially in the π‐stacking direction. Only p‐channel activity was observed in field‐effect transistors (FETs) for PHOT. The hole mobility was on the order of 10−4 cm2 V−1 s−1. Photovoltaic devices with an active layer of 1:1 blend of PHOT and PC71BM had a power conversion efficiency (PCE) of ∼0.5%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Facilitating polymer conjugation via combination of RAFT polymerization and activated ester chemistry
Authors: Wiss Kerstin T. , Theato Patrick 
Published: September 2010

AbstractThe synthesis of block copolymers via polymer conjugation of well‐defined building blocks offers excellent control over the structures obtained, but often several coupling strategies need to be explored to find an efficient one depending on the building blocks. To facilitate the synthesis of polymers with adjustable functional end‐groups for polymer conjugation, we report on the combination of activated ester chemistry with RAFT polymerization using a chain transfer agent (CTA) with a pentafluorophenyl ester (PFP‐CTA), which allows for flexible functionalization of either the CTA prior to polymerization or the obtained polymer after polymerization. Different polymethacrylates, namely PMMA, P(t‐BuMA) and PDEGMEMA, were synthesized with an alkyne‐CTA obtained from the aminolysis of the PFP‐CTA with propargylamine, and the successful incorporation of the alkyne moiety could be shown via 1H and 13C NMR spectroscopy and MALDI TOF MS. Further, the reactive α‐end‐groups of polymers synthesized using the unmodified PFP‐CTA could be converted into azide and alkyne end‐groups after polymerization, and the high functionalization efficiencies could be demonstrated via successful coupling of the resulting polymers via CuAAC. Thus, the PFP‐CTA allows for high combinatory flexibility in polymer synthesis facilitating polymer conjugation as useful method for the synthesis of block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Functionalization of carbon black nanoparticles with poly(vinylidene fluoride)
Authors: Vukićević Radovan , Hierzenberger Peter , Hild Sabine , Beuermann Sabine 
Published: September 2010

AbstractThe surface of carbon black (CB) nanoparticles was functionalized with poly(vinylidene fluoride) (PVDF) either by trapping of macroradicals or by cycloaddition. PVDF with two iodine end groups (I‐PVDF‐I) obtained from iodine transfer polymerization in supercritical CO2 was heated in the presence of CB and the CI bond was cleaved resulting in a reaction between the macroradical and the CB surface. To allow for cycloaddition of PVDF to the CB surface for a number of polymers, the iodine end groups were replaced by azide end groups. In addition, microwave irradiation was applied to the functionalization. The influence of temperature, time, polymer concentration, and polymer molar mass on the functionalization reaction was examined. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Azide/alkyne‐“click”‐reactions on amino resin materials: An LC‐ESI‐TOF analysis
Authors: Barqawi Haitham , Binder Wolfgang H. 
Published: September 2010

AbstractThis article describes the reaction of amino resins with functional molecules using the azide/alkyne‐“click”‐reaction, opening a simple chemical modification of amino resins under aqueous conditions. Alkyne‐modified melamine‐formaldehyde resins are prepared via a direct cocondensation approach using propargylic alcohol (21.6–86.3 mmol) as additive. Subsequently, alkyne‐modified mono‐, bi‐, and trinuclear melamine‐species are identified via LC‐ESI‐TOF methods proving the covalent incorporation of alkyne‐moieties in amounts of up to 3.9 mol %. Subsequent modification of the alkyne‐modified resins was accomplished by reaction of functional azides (octyl azide (1), (azidomethyl)benzene (2), 1‐(6‐azidohexyl) thymine (3), and 4‐azido‐N‐(2,2,6,6‐tetramethylpiperidin‐4‐yl)benzamide (4)) with Cu(I)Br and DIPEA as a base. The formation of triazolyl‐modified MF‐resins was proven by LC‐ESI‐TOF methods, indicating the successful covalent modification of the amino resin with the azides 1–4. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Preparation, morphology, and biolabeling of fluorescent nanoparticles based on conjugated polymers by emulsion polymerization
Authors: Wang Rui , Zhang Chao , Wang Weizhi , Liu Tianxi 
Published: September 2010

AbstractNovel nanoparticles based on conjugated polymer with good fluorescent properties were synthesized by Suzuki coupling reaction using certain surfactants as one kind of special emulsion polymerization. The luminescent properties of the prepared nanoparticles could be controlled by selecting different monomers. Without using substances comprising any heavy metal element, these fluorescent nanoparticles show very good biocompatibility with cells, thus showing potential applications in cell biolabeling, drug delivery tracing, organic light‐emitting diodes, flat displays, and other areas. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Random copolymers based on 3‐hexylthiophene and benzothiadiazole with induced π‐conjugation length and enhanced open‐circuit voltage property for organic photovoltaics
Authors: Lee Jang‐Yong , Choi Min‐Hee , Song Ho‐Jun , Moon Doo‐Kyung 
Published: September 2010

AbstractA series of donor‐acceptor low‐bandgap conjugated polymers, that is, HThmBT (m = 3, 6, 9, 12, 15), composed of regioregular 3‐hexylthiophene segments and 2,1,3‐benzothiadiazole units, were synthesized through the Stille coupling polymerization to optimize the π‐conjugation length of the polymer and the intramolecular charge transfer (ICT) effect in the polymer backbone. The polymers had relatively low optical bandgaps ranging from 1.6 to 1.72 eV. Among these polymers, HTh6BT exhibited the best device performance with a power conversion efficiency (PCE) of 1.6%. Moreover, despite being based on thiophene, HTh6BT exhibited a high‐open circuit voltage (VOC) of over 0.8 V because of its low high occupied molecular orbital (HOMO) energy level. These results provided an effective strategy for designing and synthesizing low‐bandgap conjugated polymers with broad absorption ranges and well‐balanced energy levels. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
The effect of cucurbit[n]uril on the solubility, morphology, and the photophysical properties of nonionic conjugated polymers in an aqueous medium
Authors: Tuncel Dönüs , Artar Müge , Hanay Saltuk Bugra 
Published: September 2010

AbstractThe effects of cucurbit[n]uril on the dissolution and the photophysical properties of nonionic conjugated polymers in water are described. For this purpose, a fluorine‐based polymer, namely, poly[9,9‐bis{6(N,N‐dimethylamino)hexyl}fluorene‐co‐2,5‐thienylene (PFT) was synthesized and characterized by spectroscopic techniques including 1D and 2D NMR, UV–vis, fluorescent spectroscopy, and matrix‐assisted laser desorption mass spectrometry (MALDI‐MS). For the first time, it was demonstrated that a nonionic conjugated polymer can be made soluble in water through an inclusion complex formation with CB8. The structure of the complex was elucidated by NMR experiments including 1H and selective 1D‐NOESY. This complex emits green and is highly fluorescent with fluorescent quantum yield of 35%. In contrast, CB6 or water‐soluble CB7 although they are chemically identical to CB8 do not have any effect on the dissolution and photophysical properties of PFT. By preparing a protonated version of PFT, the optical properties of PFT in methanol, protonated PFT and PFT@CB8 in water have been studied and compared. It was also observed that the morphology of the polymer PFT was affected by the presence of CB8. Thus CB8‐assisted self‐assembly of polymer chains leads to vesicles formation; these structures were characterized by DLS, AFM, SEM, and TEM fluorescent optical microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Effect of water addition on the coupling of homopolymers by click chemistry
Authors: Liu Zhilei , Hu Jiwen , Sun Jianping , Liu Guojun 
Published: September 2010

AbstractHomopolymers bearing terminal azide and alkyne groups can be coupled via click chemistry to yield diblock copolymers. When performed in solvents that dissolved both homopolymers, the click reaction was found in this study to be inefficient, probably due to the embedding of the reactive end groups inside the random coils of the polymers. The efficiency was only slightly affected by the addition of a small amount of water into the reaction mixture. However, the reaction efficiency increased dramatically near the water volume fraction where one or both of the reacting polymers began to precipitate. Further increases in water content caused the polymer(s) to undergo macroscopic phase separation and the click reaction efficiency decreased once again. A possible explanation for the observed effect of water on the polymer coupling reaction is proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Facile synthesis of core‐surface crosslinked nanoparticles by interblock RAFT polymerization
Authors: Hossain MD. Daloar , Tran Le Thi Bao , Park Jong Myung , Lim Kwon Taek 
Published: September 2010

AbstractA new, efficient method for synthesizing stable nanoparticles with poly(ethylene oxide) (PEO) functionalities on the core surface, in which the micellization and crosslinking reactions occur in one pot, has been developed. First, amphiphilic PEO‐b‐PS copolymers were synthesized by reversible addition fragmentation chain transfer (RAFT) radical polymerization of styrene using (PEO)‐based trithiocarbonate as a macro‐RAFT agent. The low molecular weight PEO‐b‐PS copolymer was dissolved in isopropyl alcohol where the block copolymer self‐assembled as core‐shell micelles, and then the core‐shell interface crosslink was performed using divinylbenzene as a crosslinking agent and 2,2′‐azobisisobutyronitrile as an initiator. The design of the amphiphilic RAFT agent is critical for the successful preparation of core‐shell interface crosslinked micellar nanoparticles, because of RAFT functional groups interconnect PEO and polystyrene blocks. The PEO functionality of the nanoparticles surface was confirmed by 1H NMR and FTIR. The size and morphology of the nanoparticles was confirmed by scanning electron microscopy, transmission electron microscopy, and dynamic laser light scattering analysis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Monodisperse superparamagnetic pH‐sensitive single‐layer chitosan hollow microspheres with controllable structure
Authors: Du Pengcheng , Liu Peng , Mu Bin , Wang Yunjiao 
Published: September 2010

AbstractFacile strategy was developed for the fabrication of the monodisperse superparamagnetic pH‐sensitive single‐layer chitosan (CS) hollow microspheres with controllable structure. The carboxyl group‐functionalized polystyrene microspheres prepared by soap‐free emulsion polymerization were used as the templates. After the Fe3O4 nanoparticles were in situ formed onto the surface of the templates, the single‐layer CS was self‐assembled and cross‐linked with glutaraldehyde subsequently. Then, the magnetic single‐layer CS hollow microspheres were obtained after the templates were removed. It was found that the feeding ratio of the monomer acrylic acid in the soap‐free emulsion polymerization had played an important role on the particle size and surface carboxyl group content of the templates, which determined the particle size and shell thickness of the magnetic single‐layer CS hollow microspheres in the proposed strategy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Polyacrylamide cryogels by photoinitiated free radical polymerization
Authors: Kahveci Muhammet U. , Beyazkilic Zeynep , Yagci Yusuf 
Published: September 2010

AbstractA novel method for the preparation of poly(acrylamide) cryogels by photoinitiated polymerization of monomeric precursors was described. A series of poly(acrylamide) cryogels were easily prepared by irradiating aqueous solutions containing acrylamide and N,N′‐methylene(bis)acrylamide as monomer and cross‐linker, respectively, in the presence of 1‐[4‐(2‐hydroxyethoxy)phenyl]‐2‐hydroxy‐2‐methyl‐1‐propane‐1‐one (Irgacure 2959) as water‐soluble photoinitiator with the help of freezing–thawing procedures. Photolysis was conducted at −13 °C isothermally through specially designed cryostat‐integrated Rayonet merry‐go‐round photoreactor. On comparing the described photochemical method with the conventional redox counter part, the polymerization is initiated, and gelation proceeds only on external stimulation by light. This way, concomitant hydrogel formation usually observed with the redox process as a result of premature polymerization during the cooling process was prevented. The obtained cryogels exhibited superfast swelling behavior. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Optimization of organic electrochemical transistors for sensor applications
Authors: Yaghmazadeh Omid , Cicoira Fabio , Bernards Daniel A. , Yang Sang Y. , Bonnassieux Yvan , Malliaras George G. 
Published: September 2010

AbstractDespite the recent interest in organic electrochemical transistors (OECTs) as chemical and biological sensors, little is known about the role that device architecture and materials parameters play in determining sensor performance. We use numerical modeling to establish design rules in two regimes of operation: We find that for operation as an ion‐to‐electron converter, the response of OECTs is maximized through the use of a gate electrode that is much larger than the channel or through the use of a nonpolarizable gate electrode. Improving the conductivity of the polymer and using a channel geometry that maximizes channel width and thickness, and minimizes channel length helps increase the response. For operation as an electrochemical sensor, the sensitivity is maximized in OECTs with gate electrodes that are smaller than their channels. The sensitivity can be improved by increasing the charge carrier mobility and the capacitance per unit area of the conducting polymer, and also its ability to be penetrated by ions from the electrolyte. A channel geometry that maximizes channel width and minimizes channel length also improves sensitivity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010
Overfill protective systems—Complex problem, simple solution
Authors: Summers Angela E. , Hearn William 
Published: September 2010

AbstractOverfills have resulted in significant process safety incidents. Longford (Australia, 1998), Texas City (United States, 2005), and Buncefield (United Kingdom, 2005) can be traced to loss of level control leading to high level and ultimately to loss of containment. A tower at Longford and a fractionating column at Texas City were overfilled, allowing liquid to pass to downstream equipment that was not designed to receive it. The Buncefield incident occurred when a terminal tank was overfilled releasing hydrocarbons through its conservation vents. The causes of overfill are easy to identify; however, the risk analysis is complicated by the combination of manual and automated actions often necessary to control level and to respond to abnormal level events. This article provides a brief summary of the Longford, Texas City, and Buncefield incidents from an overfill perspective, and highlights five common factors that contributed to making these incidents possible. Fortunately, although overfill can be a complex problem, the risk reduction strategy is surprisingly simple. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010
Preventing overpressure hazards from trapped liquids
Authors: Ramirez Juan C. , Ogle Russell A. , Carpenter Andrew R. , Morrison Delmar “Trey” 
Published: September 2010

AbstractWe examine the overlooked hazards posed by thermal expansion of trapped liquids in piping systems. Trapped liquids can generate large pressure increases with only modest temperature changes. This is a phenomenon that is often overlooked or dismissed as being of small consequence.This article discusses a simple model for estimating the overpressure hazard from thermal expansion and illustrates its use with some typical liquids encountered in heat‐transfer systems. The control of these overpressure hazards is discussed in terms of applicable safety guidelines and standards. We then illustrate the hazard of heating trapped liquids with a case study. We show that the basic cause of this catastrophic failure could have been avoided by following applicable safety standards in conjunction with a process hazard analysis of the entire system during the design phase. Our findings underscore two important design guidelines: (1) install a pressure relief device wherever liquid can be trapped and subjected to heating and (2) verify that each component of the piping system that can be isolated from pressure relief satisfies the design pressure. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010