bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymatic polymerization to polysaccharides of well‐defined structure
Authors: Shoda Shin‐Ichiro , Kobayashi Shiro 
Published: March 2011

AbstractVarious poly‐ and oligosaccharides having a well‐defined structure have successfully been synthesized via enzymatic polymerization of glycosyl fluoride monomers. All of the reaction proceeded under perfect control of regio‐ and stereochemistry. The relative direction of the synthetic cellulose (parallel or antiparallel) could be controlled in vitro in the enzyme‐promoted propagation system, and based on these findings, a new concept “allos‐selectivity” has been proposed.
Novel polymeric excipients for colon‐targeting
Authors: Hirsch Stefan , Schehlmann Volker , Kolter Karl , Bauer K. H. 
Published: March 2011

AbstractOral drug delivery to the colon is of interest for the local treatment of colonic diseases and for the systemic delivery of drugs. Our goal is to develop coating materials that are stable in gastric and small intestinal fluids and degradable in the colon by bacterial polysaccharidases. For testing colon‐degradability an in vitro model was developed. A number of polysaccharide derivatives were synthesized and tested: almost completely ethylated or acetylated galactomannans, polyurethanes with galactomannan sections, crosslinked galactomannans and dextranesters of fatty acids. Generally, degradability decreased with increasing degree of substitution. Especially crosslinked galactomannan and dextranesters with a low degree of substitution or crosslinking, respectively, are promising materials. Using an industrial coating technique tablets were coated with crosslinked galactomannan and the enzymatically induced in vitro dissolution of a model drug was investigated.
Molecular reinforcement and compatibility in rod/coil polymer blends
Authors: Eisenbach Claus D. , Fischer Karl , Hofmann Jörg , Macknight William J. 
Published: March 2011

AbstractCompatibility between a true rod‐like and a coil‐like polymer could be achieved by preparing ionomer blends of rigid polydiacetylenes with functional or ionic side groups and carboxylated or sulfonated polystyrene or sulfonated polyester‐ureaurethanes. Microphase separation was prevented through ionic contact between the blend components. The miscibility on a length scale of the rigid‐rod polymer repeating unit was proven by infrared spectroscopical, dynamic mechanical and differential scanning calorimetry analysis. The molecular reinforcement of the ionomer blends containing only a few weight percent of the reinforcer polymer amounted up to 1 order of magnitude compared to the matrix polymer as reflected from Young's modulus.
Model tests for wear measurements in plastics processing
Authors: Mennig Günter 
Published: March 2011

AbstractIn plastics processing different mechanisms of wear are observed. In view of the complex nature of the tribological systems wear can be studied systematically by model tests only. These must be developed in a manner that they coincide directly with the practical process. The youngest DKI model test, the adhesive wear tester, is described and results for various metal pairings are presented.
Polymer dispersions ‐ nanoparticles for everybody
Authors: Müller‐Mall Rudolf 
Published: March 2011

AbstractPolymer Dispersions are solving many problems of daily life. Nearly everybody is using them as an essential part of waterborn paints, adhesives, paper coating etc. For scientists, polymer dispersions are of growing interest. In this contribution a model for the film formation mechanism is proposed which is based on neutron scattering (SANS), mechanical measurements, and modelling of polymer dispersions.
Poly(3, 4‐ethylenedioxythiophene): Conductive coatings, technical applications and properties
Authors: Jonas Friedrich , Krafft Werner , Muys Bavo 
Published: March 2011

AbstractPoly(3, 4‐ethylenedioxythiophene) (PEDT) is a new polymeric organic conductor which, when combined with polystyrene sulphonic acid, produces a system that can be processed as an aqueous solution and yields effective antistatic coatings for films. The antistatic effect is achieved with coating weights of just a few mg PEDT/m2, resulting in films with a surface resistivity of 106 ω/□.
Preparation of microgels and their industrial application as fluidity controlling agents
Authors: Ishikura Shinichi 
Published: March 2011

AbstractMicrogels, intramolecularly crosslinked macromolecules with sizes of less than 100 nm, were originally manufactured via an emulsion polymerization process involving the use of novel amphiphilic oligomers containing the zwitterion moiety as emulsifiers. Application of microgels as additives to coatings has been studied here. Newtonian flow of an original coating composition was altered to pseudoplastic flow by the addition of microgels. The mechanism of this fluidity alteration was discussed in terms of electron microscopic observation of the coating composition.
Phase separation of polymer blends under shear field
Authors: Han Charles C. 
Published: March 2011

AbstractThe effect of shear flow on phase separation in critical polymer blends has been studied. For a low‐molecular‐weight blend, the response is in good agreement with the theoretical predictions of Onuki and Kawasaki. The breakup of large‐scale critical fluctuations by the flow leads to a drop in the temperature Tc at which phase separation begins. For a high‐molecular‐weight blend, the data suggest that the mode‐coupling contribution to the decay rate of composition fluctuations is significant in both the miscible and immiscible phases. However, the lack of change of structure factor in the vorticity direction implies that there is no apparent shear induced shift in Tc.
Advanced materials by functionalization of conjugated polymers
Authors: Shimidzu T. , Iyoda T. , Segawa H. 
Published: March 2011

AbstractApplications of conjugated polymers to advanced materials are demonstrated with fabrications of functional molecular materials and devices by incorporation of functional molecules to conjugated and/or conducting polymer, ultrahigh anisotropic conducting polymer materials by topological polymerizations of LB multilayers of amphiphilic pyrrol, artificial conjugated polymer superlattice by the potential‐programmed electro‐polymerization and/or electrocopolymerization, and 1‐dimensional and 2‐dimensional porphyrin arrays connected with conjugated and/or insulating molecular wires with P(V) porphyrin and others, for molecular photonics and electronics.
Polymeric arrays for directional energy and electron transfer
Authors: Fox Marye Anne 
Published: March 2011

AbstractConformationally rigid block copolymers prepared by alkyllithium‐initiated polymerization of vinyl arenes, by molybdenum amide catalyzed ring‐opening metathesis polymerization of chromophore‐labeled norbornenes, and by nickel catalyzed polymerization of functionalized isonitriles are described. Steady state and time‐resolved spectroscopic methods have been employed as tools for the structural characterization of these polymers and for studying the kinetics of long distance electron transfer.
Design and control of morphology for high performance polymer alloys
Authors: Narisawa Ikuo , Kuriyama Takashi , Schemer Bernd , Friedrich Klaus 
Published: March 2011

AbstractDuctile polymers are significantly toughened by the addition of an elastomeric phase. The rubber phase acts as a stress concentrator, cavitates during the loading process and initiates localized plastic deformation in matrix. This paper deals with the simulation of the deformation behavior of rubber toughened polycarbonate and the fracture process of the embedded rubber particle. A two‐dimensional one particle‐ and two‐particle model with varying surface‐to‐surface interparticle distances are established. The calculation showed that the polymer matrix has plastically deformed before cavitation for the one‐particle model whereas cavitation occurs in the elastic state of the matrix for the two‐particle model. Cavitation itself is proved to be a change from the particle‐system towards a void‐system for both cases. The toughness of the post‐cavitated void‐system is shown to be dependent on the surface‐to‐surface interparticle distance and the strain‐hardening characteristic of the matrix polymer.
Structure and properties of new olefin polymers
Authors: Todo Akira , Kashiwa Norio 
Published: March 2011

AbstractThe relationship between molecular structures and physical properties of linear low density polyethylenes (LLDPEs) produced with single‐site catalyst (SSC) was investigated. SSC polymerized LLDPE have excellent physical properties corresponding to its homogeneous molecular structure that had never been achieved by conventional Ziegler‐Natta catalysts. It was found that some SSCs have the capability to produce LLDPEs with narrow molecular weight distribution but excellent melt properties. This result suggests that there exist long chain branches in these LLDPEs.
Electronic transport in sigma conjugated polymers
Authors: Abkowitz M. A. , Stolka M. 
Published: March 2011

AbstractTime resolved transport studies which have now been carried out on representative alkyl and aryl substituted Si and Ge backbone polymers demonstrate that these unipolar systems to transmit holes through the specimen bulk with negligible loss of carriers to deep traps, making these materials attractive candidates for electronic device applications. Transport has been studied by measuring drift mobilities as a function of field, temperature and composition, using the small signal time‐of‐flight technique. Transport occurs among chain backbone derived states, yet exhibits behavior essentially identical to systems in which transiting carriers are known to undergo thermally activated tunneling transitions among discrete molecular sites. Thus it is suggested that disorder causes the chain backbone to be suborganized into domain like units of varying conjugation length. The sensitivity of transport to large scale thermodynamic processes, to side group substituent and to the effect of specific dopants is demonstrated.
Polyions for biocompatible materials
Authors: Barbucci Rolando 
Published: March 2011

AbstractStarting from the thermodynamic properties of some polyamidoamines, showing a protonation behaviour similar to that of small molecules, a relationship with the ability to form polymer‐polymer complexes with heparin or heparin‐like macromolecules was found.In the light of these results, new heparinisable materials (PUPA and EVAPA) were synthesised, and the surface and bulk structures were understood on the basis of the enhanced hydrophilic characters when these materials are protonated at physiological pH.
Hyperbranched polyesters: End group modification and properties
Authors: Brenner Axel R. , Voit Brigitte I. , Massa Dennis J. , Turner S. Richard 
Published: March 2011

AbstractSeveral hyperbranched polyesters have been prepared in a one‐pot polycondensation reaction. Molecular weights, viscosities and rheological behavior of these polymers have been characterized. The influence of their terminal groups on the properties and their behavior in blends will be discussed.
Surface active semifluorinated diblock copolymers prepared by group transfer polymerization
Authors: Krupers Maarten J. , Cabelo Fernando M. E. , Möller Martin 
Published: March 2011

AbstractDiblock copolymers consisting of poly(methyl methacrylate) and poly(2‐perfluorobutylethyl methacrylate) with narrow molecular weight distribution have been synthesized by group transfer polymerization. Different ratios of the PMMA block to the fluorinated block have been prepared. It was found that all polymers are surface active. Critical micelle concentrations are not dependent on the fluorinated block length. Critical surface tensions, extrapolated from Zisman plots and the dispersion force component of the surface energies extrapolated from Girifalco‐Good‐Fowkes‐Young plots were decreasing with increasing length of the fluorinated block.
Synthesis and characterization of new highly selective polyaryloxyphosphazene‐polysiloxane crosslinked copolymer films. Application to the extraction of organic compounds from water by pervaporation
Authors: Bac Alain , Roizard Denis , Lochon Pierre , Ghanbaja Iaafar 
Published: March 2011

AbstractA series of polyaryloxyphosphazene/polydimethylsiloxane (PABMP/PDMS) crosslinked copolymer films containing various PDMS contents were prepared by platinum‐catalyzed hydrosilylation reaction. The physical morphology of these membranes was characterized by IR, DSC and transmission electron microscopy. Their transport properties were studied by pervaporation of saturated ethyl acetate aqueous solutions at 30°C. Each copolymer film led to preferential permeation of ethyl acetate. Moreover, selectivity and flux proved to be higher than a PABMP membrane, increasing with the PDMS content up to a 70 wt% value. At the maximum point, an aqueous solution of 7 wt% ethyl acetate was concentrated to 97 wt% with a normalized permeation flux of 25 kg/m2.h.
New amphiphilic polymers: Poly(N‐alkylacrylamide‐CO‐vinylpyridinium)
Authors: Damas Christine , Brembilla Alain , Lochon Pierre 
Published: March 2011

AbstractA series of new amphiphilic polymers containing various amounts of N‐methyl‐4‐vinylpyridinium units as hydrophilic part and N‐dodecylacrylamide or N‐decylacrylamide units as hydrophobic part have been prepared by quaternizing the cognate copolymers. Their behaviour in aqueous solutions has been studied by viscometry, as well as by fluorescence spectroscopy and tensiometry. Results are discussed in detail and a conformational model of the macromolecules at the interface (water/methylcyclohexane) is proposed in relation to the formation of microdomains in the aqueous media.
Intrinsic styrene/maleic anhydride copolymer foam; a new green foaming technology
Authors: Steenbakkers Wim , Wallink Herman , Steuten Hans 
Published: March 2011

AbstractDSM has developed a new foaming technology based on carbon dioxide released via a controlled chemical reaction through catalyzed decarboxylation of SMA, a copolymer of Styrene (S) and maleic anhydride (MA). This carbon dioxide is thus used as an environmentally friendly blowing agent to generate intrinsically foamed SMA‐based materials. The modulus of the foam exceeds by far (factor of 2–3) the modulus of common thermoplastic foams based on e.g. PS. The tensile strength is also higher (10%). This opens up many opportunities for SMA foams in structural applications. One example is roofliners. SMA has also been successfully applied as a chemical blowing agent (e.g. in combination with ABS) for the production of a high‐density foam on an injection moulding machine or an extruder. In this paper the chemical background, processing, properties and some applications of intrinsically foamed SMA will be discussed.
Application of polyethylene in reconstruction otologic surgery ‐ foil and porous polyethylene
Authors: Borsig Eberhard , Krošlák Milan 
Published: March 2011

AbstractLow density polyethylene was prepared in the form of foil and porous plate and used as an implant material for otolaryngology. After clinical testing the foil was introduced into reconstruction surgery of middle ear. The porous polyethylene is undergoing the clinical testing. It also shows a promising application in reconstruction maxillofacial surgery. In the course of testing of polyethylene implants no reaction to the implanted foil was observed for any patient.
Polydimethylsiloxanes with amylose side chains by enzymatic polymerization
Authors: Braunmühl Volker V. , Stadler Reimund 
Published: March 2011

AbstractMaltoheptaonamide modified polydimethylsiloxane was prepared applying a simplified synthetic pathway in the derivatization sequence of the carbohydrate. The products were characterized by 13C NMR and FT‐IR spectroscopy. The glucan side chains of these “sweet siloxanes” were elongated by enzymatic catalysis with potato phosphorylase.
Nanoarchitectures and molecular composites as advanced materials
Authors: Wegner Gerhard 
Published: March 2011

AbstractA molecular composite is defined as a supramolecular structure in which extended chains are embedded in a continuous matrix of liquid‐like or glassy nature. A nanoarchitecture is obtained via assembly of shape persistent objects to create two‐dimensional or three‐dimensional patterns. These two concepts have been realized by the design of rod‐like, that is shape persistent, backbones to which short and flexible side chains are attached. The latter acts as a solvent skin providing the solubility and processability to the shape persistent backbone elements. The interaction between the solvent skins of the individual rods create a continuous matrix in which the backbone elements are embedded as reinforcing elements.
Approaches to polymer superlattice and molecular device
Authors: Shimidzu Takeo 
Published: March 2011

AbstractApproaches to polymer superlattice and molecular devices are shown, demonstrating with functional molecule material by incorporation of a functional molecule into the conducting polymer, conjugating copolymer superlattice by a novel potential programmed electro polymerization, ultrahigh anisotropic conductive LB heterolayers, and porphyrin arrays connected with conducting molecular wire and insulating molecular wire.These results show a practical method to fabricate ultimate functional materials such as molecular device which is the smallest functional material, and quantum functional material which creates a novel nature.
Percolation in carbon black filled epoxy resin
Authors: Schueler Ruediger , Petermann Juergen , Schulte Karl , Wentzel Hans‐Peter 
Published: March 2011

AbstractThe conditions to form a conductive network in carbon black filled epoxy resin were examined. It was found that the formation is controlled by particle‐particle interaction which can be influenced by shear forces or by the ionic concentration of the resin. Therefore the network morphology and thus the percolation threshold depends strongly upon the processing route. On best conditions the percolation threshold was reduced to 0.06 vol.‐%. That a continuous network can form with such a low volume fraction can be explained by the fractal dimension of agglomerates the network is made of.
Disulfide‐polyaniline composite cathodes for rechargeable batteries with high energy density
Authors: Oyama Noboru , Tatsuma Tetsu , Sotomura Tadashi 
Published: March 2011

AbstractA composite cathode was prepared from a solution containing 2,5‐dimercapto‐1,3,4‐thiadiazole (DMcT) and polyaniline (PAn). The resulting cathode exhibits 80% of the theoretical capacity. Furthermore, an energy density of over 600 Wh/kg‐cathode and a discharge voltage of 3.4 V are obtained, when it is coupled with a lithium anode. Additional advantages of the present cathode material over the conventional metal oxides are the ease in disposal by incineration, the low pollution and the low cost. Current capability of 137 A/kg‐cathode is achieved by adding a polypyrrole derivative to the DMcT‐PAn composite and coupling it with a copper current collector.
Recent advancement of ion‐conductive polymers
Authors: Ohno Hiroyuki , Ito Kaori 
Published: March 2011

AbstractThe inorganic salt‐containing poly(ethylene oxide) is a representative starting system to design high ionic conductors. Higher ionic conductivity is expected to be obtained by the improvement of both or either of carrier ion concentration and carrier ion mobility. The recent approaches to make more excellent ion conductive polymers were classified into three groups, i.e., new salts, new polymer matrix, and new system. Some interesting approaches are also reviewed in this paper.
Metal complexes of partially phosphorylated poly(vinyl alcohol) ‐ functions and applications
Authors: Shirai Hirofusa , Koyama Toshiki , An Ying , Hanabusa Kenji , Hojo Nobumasa 
Published: March 2011

AbstractThe highly phosphorylated poly(vinyl alcohol)s (P‐PVAs: degree of phosphorylation 70 mol‐%) were synthesized by the reaction of PVA, dicyandiamide, urea and orthophosphoric acid in DMF solution. A range of P‐PVAs having differents contents (3.3 to 70 mol‐%) of phosphoric acid groups can be obtained by the change of reaction time via the same procedure. The complex formation of Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) ions with P‐PVA thus obtained was investigated by means of potentiometric titration and spectroscopy. By chemical crosslinking reaction of P‐PVA with glutaraldehyde, novel anionic polyelectrolyte gels were easily prepared. The degree of swelling and the hardness of hydro‐gels can be changed by varying the crosslinking reaction condition. The ion exchange capacity and metal ion selectivities of a cation exchange resin prepared from P‐PVA hydrogel have been estimated. Flame‐retardation of metal‐P‐PVA complexes have also studied. The Ni(II)‐P‐PVA complex showed a good flame‐retardation. The molecular composites of the P‐PVA salts of cations such as K+ or R4N+ (R = CH3 etc.) were also prepared. These composite polymers showed single ionic conductivity (σ rt > 10−4 S · cm−1).
Polyelectrolyte‐surfactant complexes: Highly ordered microphase‐separated polymers
Authors: Antonietti Markus , Burger Christian , Conrad Jürgen , Kaul Antje 
Published: March 2011

AbstractPolyelectrolyte‐Surfactant complexes (PE‐Surfs) represent a new class of microphase‐separated polymers showing a variety of phase modifications with a high degree of supramolecular order. The complexes are simply made by common precipitation from water and are easy to handle. In addition, they exhibit an exciting combination of product properties coming from the surfactant as well as from the polyelectrolyte side. In this article, an overview of the current work on the solid‐state properties of these materials as well as a personal outlook to future trends is given.
Self‐assembly of domain wall of molecular twist defects in polyethylene crystal
Authors: Balabaev Nikolai K. , Gendelman Oleg V. , Manevitch Leonid I. , Mazo Michael A. 
Published: March 2011

AbstractTwo‐dimensional structural defects in a polyethylene crystal (twist domain walls) are investigated by means of analytic treatment and molecular dynamics simulation. The formation of the domain wall as a result of relaxation of the crystal from different initial states is studied and parameters of this type of defects are calculated.
Synthesis and investigation of liquid polyurethane metal complexes
Authors: Davletbaeva Ilsiya M. , Kirpichnikov Petr A. , Rakhmatullina Alevtina P. 
Published: March 2011

AbstractPolyurethane metal complexes (PUMC's) have been synthesized on the basis of the polynucleus complexes of Cu(II) and Fe(III), where the metals are connected by chlorine bridges, symmetrical aromatic diisocyanates and azoaromatic compounds; these complexes exhibit properties of thermotropic liquid crystals. The mesophase temperatures of the substances range from is 20–80 °C and 60–110°C. Specific electric resistance of the synthesized liquid crystal systems is 103‐105 ω‐cm.
The kinetics laws for polymer collapse and biopolymer folding
Authors: Dawson K. A. , Timoshenko E. G. , Kuznetsov Yu. A. 
Published: March 2011

AbstractWe discuss some recent ideas relating to the folding and other conformational transitions of polymers. In particular we emphasize that it is possible to conceive the accompanying kinetic processes as a problem in non‐equilibrium statistical mechanics. In this sense it should be possible to develop such methods to deduce the kinetic laws in the vicinity of various conformational transitions. To establish the ideas we first study the well known problem of the collapse transition of a homopolymer. We then turn to conformational transitions in periodic and random copolymers. We offer a brief survey of the status of these ideas in applications to biopolymeric conformational kinetics.