bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resorcinol‐Formalin Foam Balls Via Gelation of Emulsion Using Phase‐Transfer Catalysts
Authors: Ito Fuyumi , Nagai Keiji , Nakai Mitsuo , Norimatsu Takayoshi 
Published: October 2005

AbstractSummary: Highly spherical (98.5%) low‐density foam balls with 1‐mm diameters were fabricated from a density‐matched emulsion consisting of a resorcinol/formalin aqueous solution and a (mineral oil and carbon tetrachloride) mixture. Phase‐transfer catalysts of carboxylic acid were utilized to induce gelation of the emulsion. The gelation process was monitored by a mechanical test. Gelation forming ball shapes happened within 20–30 min, depending on the catalysts, at room temperature. The gelation time decreased with high‐catalyst concentration. Acids with long alkyl chains did not induce gelation and no balls were obtained. The gelated balls were dried to obtain foam via an exchange of the solvent with 2‐propanol and extraction using the supercritical fluid CO2. The density obtained from the catalyst was 0.15–0.16 g · cm−3. SEM images revealed surface membrane formation, which can be explained by local concentration at the interface of W/O. We observed different bulk foam cell sizes, which may depend on the catalysts and, therefore, on the different gelation rates.Structure of a highly spherical low‐density foam ball with 1‐mm diameter.magnified imageStructure of a highly spherical low‐density foam ball with 1‐mm diameter.
Transesterification of Poly(4,4′‐isopropylidene‐2,2′‐dimethyldiphenylene terephthalate) and Poly(ethylene adipate) Blend in Solution
Authors: Krentsel Liya B. , Markova Gali D. , Kudryavtsev Yaroslav V. , Filatova Marina P. , Vasnev Valerii A. , Litmanovich Arkady D. , Platé Nikolay A. 
Published: October 2005

AbstractSummary: Transesterification of poly(4,4′‐isopropylidene‐2,2′‐dimethyldiphenylene terephthalate) and poly(ethylene adipate) (PEA) has been carried out in concentrated o‐dichlorobenzene solution at 210 °C with Bu2SnO as a catalyst. According to GPC data, during transesterification the reaction product acquires Flory MWD and only a slight degradation of chains proceeds in the system: on average each chain having undergone about one scission in 100 min. Chain structure of the reaction products was studied using 1H NMR spectroscopy. The kinetic and statistical analysis of the process was performed using following assumptions: transesterification proceeds in a homogeneous medium as a reversible second‐order reaction between diads, and the product chain structure obeys the first‐order Markov statistics. Calculated dependences of the parameters characterizing an evolution of the chain structure during the reaction fit experimental data fairly well. In 100 min the reacting system reaches a state close to the equilibrium. The difference between distributions of diads of residues and units is considered.Change of the terephthalate‐centered r‐triads content with time.magnified imageChange of the terephthalate‐centered r‐triads content with time.
Conjugated Silole and Carbazole Copolymers: Synthesis, Characterization, Single‐Layer Light‐Emitting Diode, and Field Effect Carrier Mobility
Authors: Wang Yan , Hou Lintao , Yang Kaixia , Chen Junwu , Wang Feng , Cao Yong 
Published: October 2005

AbstractSummary: Soluble conjugated random and alternating copolymers (PCz‐PSP) derived from N‐hexyl‐3,6‐carbazole (Cz) and 1,1‐dimethyl‐2,3,4,5‐tetraphenylsilole (PSP) were synthesized by palladium(0)‐catalyzed Suzuki coupling reactions. The feed ratios of Cz to PSP were 95:5, 90:10, 80:20, 70:30, and 50:50. Chemical structures and optoelectronic properties of the copolymers were characterized by 1H NMR, 13C NMR, UV absorption, cyclic voltammetry, photoluminescence, electroluminescence, and field effect transistor. HOMO levels of the copolymers are between −5.15 and −5.34 eV. Single‐layer devices with a configuration of ITO/copolymer/Ba/Al were fabricated and the copolymer with PSP content of 20% displayed the highest external quantum efficiency of 0.77%. Field effect transistors with tantalum pentoxide‐polyacrylonitrile double insulators demonstrated that hole mobilities of the copolymers decreased with their PSP contents, and the hole mobility up to 9.3 × 10−6 cm2 · (V · s)−1 could be achieved.Synthesis of coplymers derived from 3,6‐carbazole and silole.magnified imageSynthesis of coplymers derived from 3,6‐carbazole and silole.
A New Copolymer Containing Perylene Bisimide and Porphyrin Moieties: Synthesis and Characterization
Authors: He Xiaorong , Liu Huibiao , Li Yuliang , Liu Yang , Lu Fushen , Li Yongjun , Zhu Daoben 
Published: October 2005

AbstractSummary: A novel copolymer containing perylene bisimide and porphyrin units was synthesized through a Wittig‐type coupling reaction and characterized. An electrochemical experiment showed its electronic properties. Optoelectronic measurements showed a steady and rapid cathodic photocurrent response of the polymer film. The features of copolymer colloids were also studied by UV‐Vis spectrometry and TEM. A large quantity of nanoparticles were observed with TEM, with a mean diameter of 200 nm. The size effect leads the absorption wavelength of the nanoparticles to be red‐shifted, which is consistent with the results of UV‐Vis spectrometry.TEM image of the polymer colloid.magnified imageTEM image of the polymer colloid.
Michael Addition Polymerizations of Trifunctional Amines with Divinyl Sulfone
Authors: Zheng Zhiju , Pan Caiyuan , Wang Ding , Liu Ye 
Published: October 2005

AbstractSummary: The mechanisms of the Michael addition polymerization of N‐aminoethyl piperazine (AEPZ) with divinyl sulfone (DVS) were clarified based on the reactivity sequence of three different amines in AEPZ: 2° amine in piperazine ring > 1° amine ≫ 2° amine formed in situ. When the feed molar ratio of DVS to AEPZ was 1:1, the polymerization of AB intermediate formed proceeded, and the linear poly(sulfone amine) containing secondary and tertiary amines in the backbones were produced. The linear structure of the product was confirmed by NMR spectra, and the molecular weights, molecular weight distribution, and properties of poly(sulfone amine)s were characterized by GPC, DSC, and TGA.Polymerization of linear poly(DVS‐AEPZ).magnified imagePolymerization of linear poly(DVS‐AEPZ).
Multicyclic Poly(ether ketone)s by Polycondensation of 1,3,5‐Tris(4‐fluorobenzoyl)benzene with Various Diphenols
Authors: Kricheldorf Hans R. , Hobzova Radka , Vakhtangishvili Lali , Schwarz Gert 
Published: October 2005

AbstractSummary: 1,3,5‐Tris(4‐fluorobenzoyl)benzene (TFBB) was polycondensed with silylated 4,4′‐dihydroxybiphenyl, bisphenol‐A or 4‐tert‐butylcatechol in N‐methylpyrrolidine with K2CO3 as a promoter. The TFBB/diphenol feed ratio was varied from 1.0:1.0 to 1:0:1.5. Partial cross‐linking was observed with the stiff 4,4′‐dihydroxybiphenyl, even at the 1.0:1.0 ratio. With bisphenol‐A, no gelation took place up to a feed ratio of 1.0:1.3, indicating a high cyclization tendency. With 4‐tert‐butylcatechol, no cross‐linking occurred up to the 1.0:1.5 ratio, proving an even higher cyclization tendency. The formation of cyclic, bicyclic and multicyclic oligo‐ and polyethers was detected by means of MALDI‐TOF mass spectrometry for all reaction products. These results demonstrate that increasing chain stiffness reduces the influence of cyclization. Cyclization proved unavoidable, however, and a high cyclization tendency prevents the formation of hyperbranched and networked structures.
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Simple Synthesis of Hierarchically Structured Silicas by Poly(ethyleneimine) Aggregates Pre‐Organized by Media Modulation
Authors: Jin Ren‐Hua , Yuan Jian‐Jun 
Published: October 2005

AbstractSummary: In this paper, we describe the multiple morphogenesis of poly(ethyleneimine) (PEI)‐directed silicas through the facile tuning of the media in which the PEIs pre‐organize. The silica shapes and structures ranged from nanofiber‐based asters, fans, particles, plates, and/or curved films to large aggregates composed of unit nanoribbon structures and networks that contained nanospheres or particles, depending on the media compositions or media modulations coupled with the polymer concentrations and chain architectures. We found that the media modulations not only controlled the formation of the silica unit structures but also manipulated the hierarchical structures based on the unit silicas. Furthermore, methanol modulation successfully allows us to elucidate the dependence of silica deposition ability on the polymer chain architectures that cause subtle differences in their aggregates. The approach of methanol modulation to obtain shaped silicas, which involves both PEI aggregation and silica deposition at room temperature, is of particular interest to applications for the immobilization of bioactive components.
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Linear Viscoelastic Characteristics of Poly(trimethylene terephthalate)/Polycarbonate Blends in the Melt State
Authors: Yavari Ahmad , Asadinezhad Ahmad , Jafari Seyed Hassan , Khonakdar Hossein Ali , Ahmadian Shahin , Böhme Frank 
Published: October 2005

AbstractSummary: Blends of poly(trimethylene terephthalate) (PTT) and polycarbonate (PC) over full composition range were prepared using a twin‐screw extruder. A glycidyl methacrylate‐based terpolymer was used to modify the interface of the blends. Morphological examinations were carried out using transmission electron microscopy (TEM) and confirmed the biphasic structure of the blends. Dynamic rheological response of the blends was recorded in the linear viscoelastic region. It was observed that addition of the terpolymer to the system increases the dynamic shear moduli and complex viscosity of the blends, which is attributed to interactions of the terpolymer at the interface of two phases leading to a restricted chain mobility of the blend components. The Veenstra model was found to be able to describe dynamic shear modulus of the PTT/PC 50/50 blend; however, for the compatibilized blend of PTT/PC 50/50, the fit is not as good as that of uncompatibilized system, which is believed to be due to formation of micelles in this system.Dynamic storage modulus of the compatibilized and uncompatibilized PTT/PC blends.imageDynamic storage modulus of the compatibilized and uncompatibilized PTT/PC blends.
Di‐Channel Polyfluorene Containing Spiro‐Bridged Oxadiazole Branches
Authors: Zhu Rui , Wen Gui‐An , Feng Jia‐Chun , Chen Run‐Feng , Zhao Lei , Yao He‐Ping , Fan Qu‐Li , Wei Wei , Peng Bo , Huang Wei 
Published: October 2005

AbstractSummary: A p–n di‐channel copolymer based on polyfluorene (PF) has been designed and prepared. Branches containing oxadiazole units are attached to the PF backbone through the spiro‐structure and act as channels to improve the electron affinity; these branches form a steric ‘di‐channel’ framework with the polymer backbone. The polymer possesses excellent thermal stability. The lowest unoccupied molecular orbital energy level of the polymer is significantly altered in comparison with poly(9,9‐dioctylfluorene‐2,7‐diyl).Schematic of the di‐channel polyfluorene synthesized here and the mechanism of energy transfer through the structure.magnified imageSchematic of the di‐channel polyfluorene synthesized here and the mechanism of energy transfer through the structure.
Preparation of a Polyethylene Latex by Catalytic Hydrogenation of a Polybuta‐1,4‐diene‐Based Dispersion
Authors: Chemtob Abraham , Heroguez Valérie , Gnanou Yves 
Published: October 2005

AbstractSummary: Fully linear polyethylene‐based latexes have been prepared by the hydrogenation of polybuta‐1,4‐diene dispersions. The latter were synthesized via dispersion ring‐opening metathesis polymerization of cycloocta‐1,5‐diene, and hydrogenated using RuCl2(PPh3)3 as catalyst, without any further treatment. A high hydrogenation efficiency was achieved as demonstrated by different techniques including DSC, and 1H NMR and FT‐IR spectroscopy. The hydrogenation process could be carried out without detrimental effect on particle size and colloidal stability as evidenced by optical microscopy and light scattering analysis.Optical microscopy photograph of a polybutadiene‐based dispersion after hydrogenation. No change in size is observed.magnified imageOptical microscopy photograph of a polybutadiene‐based dispersion after hydrogenation. No change in size is observed.
A New Acyclic α‐Hydrogen Bearing Nitroxide and its Corresponding Alkoxyamine for Stable Free Radical Polymerization
Authors: Flakus Silke , Mandel Kerstin , Bartsch Martina , Schmidt‐Naake Gudrun 
Published: October 2005

AbstractSummary: The synthesis of the new α‐hydrogen bearing nitroxide, 2,2,5‐trimethyl‐4‐(isopropyl)‐3‐azahexane‐3‐oxyl (BIPNO) (4), and its corresponding alkoxyamine, N‐tert‐butyl‐N‐(1‐isopropyl‐2‐methyl‐propyl)‐O‐(1‐phenyl‐ethyl)‐hydroxylamine (PhEt‐BIPNO) (7), are described in this paper. Reaction of styrene with the new nitroxide in the presence of a Jacobsen‐like manganese catalyst, Mn(salen)Cl, at ambient atmosphere afforded the alkoxyamine in 96% yield. Styrene and n‐butyl acrylate were polymerized in bulk in the presence of the new alkoxyamine. The alkoxyamine turned out to be a suitable “initiator” for controlled radical polymerization.Structure of α‐hydrogen bearing nitroxide and its corresponding alkoxyamine.magnified imageStructure of α‐hydrogen bearing nitroxide and its corresponding alkoxyamine.
Photoinitiators with Functional Groups, 8
Authors: Jauk Sigrid , Liska Robert 
Published: October 2005

AbstractSummary: Bimolecular type‐II photoinitiators for radical photopolymerization suffer from a diffusion‐controlled limitation of reactivity and from deactivation by back electron transfer. Here, a very efficient concept to increase the photoinitiator activity by the covalent binding of phenylglycine to benzophenone using a methylene spacer is presented. Photo‐DSC experiments proved that the rate of polymerization can be tripled in comparison to a physical mixture of the components or an industrially applied system with triethanolamine as coinitiator.Structure of the new photoinitiator synthesized here.magnified imageStructure of the new photoinitiator synthesized here.
Micelles Formed by Cylindrical Brush‐Coil Block Copolymers
Authors: Khelfallah Nawel , Gunari Nikhil , Fischer Karl , Gkogkas Giorgos , Hadjichristidis Nikos , Schmidt Manfred 
Published: October 2005

AbstractSummary: Amphiphilic cylindrical brush‐coil block copolymers consisting of a polystyrene coil and a cylindrical brush block with poly(acrylic acid) side chains are prepared by ATRP of t‐butylacrylate from a block comacroinitiator. Upon acidolysis of the poly(t‐butylacrylate), water‐soluble polymers were obtained that were observed to form micelles consisting of 4–5 block copolymers on average in aqueous solution. The star‐like nature of such micelles was clearly visualized by scanning force microscopy.Schematic of coil‐cylindrical brush block copolymer PS‐b‐(PiBEMA‐g‐PAA), its AFM image clearly showing the main chain and the PAA corona of the cylindrical brush block.magnified imageSchematic of coil‐cylindrical brush block copolymer PS‐b‐(PiBEMA‐g‐PAA), its AFM image clearly showing the main chain and the PAA corona of the cylindrical brush block.
Facile Fabrication of Functional Polypyrrole Nanotubes via a Reactive Self‐Degraded Template
Authors: Yang Xiaoming , Zhu Zhengxi , Dai Tingyang , Lu Yun 
Published: October 2005

AbstractSummary: Polypyrrole nanotubes with high electric conductivity and azo function have been fabricated in high yield via an in‐situ polymerization. During the process fibrillar complex of FeCl3 and methyl orange (MO), acting as a reactive self‐degraded template, directed the growth of polypyrrole on its surface and promoted the assembly into hollow nanotubular structures.TEM image of uncompleted PPy nanotubes synthesized in MO solutions after reaction for 40 min.magnified imageTEM image of uncompleted PPy nanotubes synthesized in MO solutions after reaction for 40 min.
Non‐Lipschitzian control algorithms: application to a nanofriction model
Authors: Protopopescu Vladimir , Barhen Jacob , Amselem Gabriel , Dahan Julien 
Published: October 2005

AbstractRecently we proposed a new feedback control algorithm for quantities describing global features of non‐linear dynamical systems. The performance of the algorithm, which is based on the concepts of non‐Lipschitzian dynamics and global targeting, has been successfully demonstrated for systems confined to one spatial dimension and for a specific targeted global quantity, namely the velocity of the centre of mass. In this paper we extend the scope of the non‐Lipschitzian control scheme to multi‐dimensional systems and different targeted quantities. We illustrate the efficiency of the non‐Lipschitzian feedback w.r.t. the ordinary (Lipschitzian) feedback, as well as the robustness and accuracy of the algorithm in a broad variety of control scenarios on the 2‐d Frenkel‐Kontorova model for nanofriction. Published in 2005 by John Wiley & Sons, Ltd.
Understanding self‐organization of the inclusion complexes in the solid state—DSC, NMR and DFT studies
Authors: Potrzebowski M. J. , Heliński J. , Olejniczak S. , Ciesielski W. 
Published: October 2005

AbstractThe relationship between DSC profiles and changes of 13C and 31P the spin–lattice relaxation time of the host and 1H T1 of guest in inclusion complexes of bis[6‐O,6‐O′‐(1,2:3,4‐diisopropylidene‐α‐D‐galactopyranosyl)thiophosphoryl] disulfide (DGTD) with n‐propanol is discussed in term of guest migration in the crystal lattice. 1H–13C FSLG HETCOR experiment recorded with different contact times was employed to establish the guest localization in the crystal lattice for different modifications of the inclusion complex. The migration pathway of the guest was verified by means of theoretical DFT calculations. Copyright © 2005 John Wiley & Sons, Ltd.
Experimental techniques in high‐vacuum anionic polymerization
Authors: Uhrig David , Mays Jimmy W. 
Published: October 2005

AbstractExperimental methods used in high‐vacuum anionic polymerization are described in detail, with extensive illustrations to demonstrate proper procedures and techniques. These descriptions include construction and operation of the vacuum line, handling purification chemicals, ampulization techniques, short‐path distillations, initiator synthesis, polymerization procedures, and linking reactions using chlorosilanes. A primary emphasis is placed on safety. We believe that this review of these methods will be useful to scientists working in the field of anionic polymerization and may also benefit other researchers in performing tasks requiring ultra‐high‐purity reaction conditions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6179–6222, 2005
Salt effect on polyaddition of bifunctional cyclic carbonate and diamine
Authors: Ochiai Bungo , Inoue Shoko , Endo Takeshi 
Published: October 2005

AbstractThe effect of various additives was examined for polyaddition of bifunctional cyclic carbonate and diamine giving poly(hydroxyurethane). Lithium chloride and lithium fluoride especially proved to be effective for the acceleration that resulted in giving polymers with higher molecular weights without coloration. The IR spectroscopic analysis of the mixtures of the additives and the carbonate monomer suggested that the acceleration with the lithium salts depends on the activation of the carbonyl group to enhance its electrophilicity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6282–6286, 2005
Polyimides based on new diamines having pendant imide groups
Authors: Kricheldorf Hans R. , Fan Shu‐chin , Vakhtangishvili Lali , Schwarz Gert , Fritsch Detlef 
Published: October 2005

AbstractNew aromatic diamines were prepared in two steps from 4,5‐dichlorophthalic anhydride and primary amines. The resulting 4,5‐dichlorophthalimide was reacted with 4‐mercaptoaniline, so that the chloroatoms were substituted by the mercapto groups (via the sulfide anions). The new diamines were polycondensed either with the diphenyl ether 3,3′,4,4′‐tetracarboxylic anhydride or with bicyclooctane tetracarboxylic anhydride. These polycondensations were conducted in boiling m‐cresol with azeotropic removal of water. The isolated polyimides were characterized by viscosity measurement, IR‐spectroscopy, elemental analyses, and MALDI‐TOF mass spectrometry. The mass spectra evidenced a high content of cyclic polyimides, indicating nearly perfect reaction conditions. The mass spectra also proved the formation of copolymers containing one diamine with a trialkylamine group in the side chain. High glass transition temperatures but a low crystallization tendency were found by DSC measurements. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6272–6281, 2005
Multicyclic polyethers with pendant keto groups by polycondensation of silylated 1,1,1‐tris(4‐hydroxyphenyl)ethane
Authors: Kricheldorf Hans R. , Vakhtangishvili Lali , Schwarz Gert , Prosenc Marc 
Published: October 2005

Abstract1,1,1‐Tris(4‐trimethylsiloxyphenyl)ethane, (silylated THPE), was polycondensed with 2,4‐difluoroacetophenone and 2,4‐difluorobenzophenone. All polycondensations were performed in N‐methylpyrrolidone with K2CO3 as promotor. The feed ratio THPE/difluoroaromat was varied from 1.0:1.3 to 1.0:1.5. Instead of hyperbranched polymers or gels, soluble multicyclic oligo‐ and polyethers were identified as main reaction products by MALDI‐TOF mass spectrometry in all experiments. At feed ratios around 1.0:1.5 multicycles free of functional group were the main products. However, when isomeric a2‐monomers such as 2,6‐difluoroacetophenone, 2,6‐difluorobenzophenone (or 2,6‐difluorodiphenylsulfone) were used, gelation occurred at feed ratios as low as 1.0:1.1. An explanation of the different cyclization tendencies on the basis of different conformations is discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6233–6246, 2005
Solvent effect on the atom transfer radical polymerization of allyl methacrylate
Authors: París Rodrigo , de la Fuente José Luis 
Published: October 2005

AbstractThe controlled radical polymerization of allyl methacrylate by atom transfer radical polymerization was carried out in solution at 70 °C, with ethyl 2‐bromoisobutyrate as the initiator and copper halide (CuX, where X is Cl or Br) with N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalyst system. Kinetic analyses demonstrated that all the homopolymerization reactions showed a general behavior characterized by two clearly differentiated stages. Thus, in the early stage, the conversion increased continually with the time, independently of the solvent employed. In the second stage, a deceleration process took place, and a limit conversion was achieved, depending on the polarity and amount of the solvent used. The dependence of both the gel formation and limit conversion, as well as the molecular characteristics of poly(allyl methacrylate)s formed with different experimental parameters, such as the initial monomer concentration, the solvent employed, and the type of halide used as a catalyst, was also examined. The prepared polymers were characterized by size exclusion chromatography, Fourier transform infrared, and one‐ and two‐dimensional nuclear magnetic resonance spectroscopy. Moreover, chain‐growth experiments with butyl acrylate as the comonomer proved the living character of the poly(allyl methacrylate)s obtained, with these used as macroinitiators. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6247–6261, 2005