Polymers - Vol. 58, No. 1 (January, 2009)

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Vol. 58, No. 1 (January, 2009)

The Dynamic Percolation Behavior of Polymer Composites Filled with Carbon Black
Shigeo ASAI
Department of Chemistry and Materials Science, Tokyo Institute of Technology

The electrical conductivity of apolymer filled with electrical conductivparticles, such as carbon black, depends on the filler dispersionstate, which is largely affected by not only the composition of the material but also the processing conditions. The dynamic percolation phenomenon, which is caused by the formation of electrical conductive network and can be monitored via time dependence of the electrical conductivity at high temperature, is important in processing. The dynamic percolation behavior depends on many factors such as the size and shape of fillers and the viscosity of a polymer matrix, because it occurs due to the random walk of fillers in the polymer with thermal motion.
The dynamic percolation behavior at various temperatures in air and under supercritical CO2 was investigated. Polymer Preprints, Japan 2008, 57, 4492

 Phosgene-Free Synthesis of N-Carboxyl Anhydride
(NCA) Based on Intramolecular Cyclization of
Activated Urethanes of α-Amino Acid
Koichi KOGA, Atsushi SUDO, and Takeshi ENDO*
Molecular Engineering Institute, Kinki University
A new phosgene-free synthesis of α-amino acid-N-carboxyanhydride(NCA) has been achieved through a three-step process. The first step is derivation of amino acids into their imidazolium salts 1, of which high solubility in various organic solvents facilitated their N-carbamoylation with diphenyl carbonate in the second step. The resulting urethane derivatives 2 underwent cyclization efficiently in the presence of carboxylic acid-type promoter, to give the corresponding NCAs in excellent yields.
Polymer Preprints, Japan 2008, 57, 2262.

Core-shell Polymer Structure in 3DOM Inorganic Matrix
Kiyoshi KANAMURA
Department of Applied Chemistry, Graduate School of Urban
Environmental Science, Tokyo Metropolitan University
Core-shell structure consisting of two different polymers was fabricated in a three- dimensionally ordered macroporous (3DOM) silica membrane for high selective permeation of protons. The surface of 3DOM pores was coated with proton-conducting polymer (sulfonated poly(1,4phenylene ether ether sulfone), SPEES) and the remaining hollow regions were occupied by methanol tolerant polymer (polystyrene, PS) by stepwise filling method. The composite membrane exhibited high proton conductivity even though the shell layer of SPEES was very thin, due to high transfer of protons in the heterointerface between SPEES and silica. On the contrary, methanol permeation was completely suppressed, resulting in an excellently high selectivity of proton transfer in the membrane. Polymer Preprints, Japan 2008, 57, 3461.

Advanced Polymers for Nanobiotechnology –Development of Polymer-based Nanodevices for Pinpoint Therapy and Diagnostics
Kazunori KATAOKA
Department of Materials Engineering, The University of Tokyo
Polymeric micelle, the selfassembly of block copolymers with core-shell architecture, is a promising nanodevice for drug and gene delivery. There are
several relevant properties in polymeric micelle as a nanodevice system, such as longevity in blood circulation, tissue-penetrating ability, spatial and temporal
controlled drug release, and reduced inherent toxicity.
Also, engineering of the block copolymer structure allows the preparation of polymeric micelles with integrated smart functions,such as targetability on the surface as well as stimulisensitivity in the intermediate layer and the core, e.g., cyclic RGD peptide ligand, detachable PEGylation and crosslinking stabilization through disulfide bond, which is cleaved in intracellular reductive conditions. Polymer Preprints, Japan 2008, 57, 4950.

Development of New Functional Network Polymers by Controlling the Network Chain Orientation
Mitsukazu OCHI
Faculty of Chemistry, Materials and Bioengineering, Kansai University
The control of network chain orientation was attempted by utilizing the self-organization of network chains in the curing process of the liquid crystallin
epoxy and acrylic resins including mesogenic groups. The pattern of the network orientation depended strongly on the curing conditions (for example,
temperature, kinds of external force). The toughness of network polymers increased more than one decade with the progress of the orientation of network
chains. This may be due to thedecreace of defects in the network structure. In addition, the high thermal conductivity was developed in the oriented networks. The transportation of thermal energy is mainly occurred along the chain direction in the oriented networks.
Polymer Preprints, Japan 2008, 57, 5391.

Temperature-Responsive Surfaces for Cell Sheet
Tissue Engineering Therapy
Teruo OKANO
Institute for Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, TWIns
Ideal tissue construction in vitro and in vivo would be achieved by cell sheet engineering technologies with manipulation of a single layer or multilayered cell sheets. Cultured cells and cell sheets arenoninvasively harvested from our developed temperature-responsive surfaces, poly(N-isopropylacrylamide)- grafted tissue culture polystyrene dishes, only by lowering the temperature from 37 to 20°C. In collaboration with medical doctors and engineers, we have achieved clinical studies for the patients with corneal stem-cell deficiencies, dilated cardiomyopathies, and esophageal cancers. New therapeutic researches utilizing periodontal ligaments, bladder epithelial, liver cell sheets are also started. Consequently, the coordination and/or the fusion of advance technologies such as biology,medicine, polymer science, and engineering are essential to realize the globalization of regenerative medicine.
Polymer Preprints, Japan 2008, 57, 4807.

Novel Photoresist for 10μm L/S Pattern Fabrication in Screen Process Printing
Masamitsu SHIRAI
Department of Applied Chemistry, Osaka Prefecture University
A new positive photoresist based on polymethacrylate was developed and used for the fabrication of screen plate. This resist gave a positive image on exposure at 365 nm and development with aqueous base. Since the new resist contains a crosslinking agent, it gave crosslinked materials on exposure at 254 nm. What is unique about the resist is that it is adjusted to react diffently to two wavelengths in a selective manner. With the use of a silver paste and the screen plate on which a pattern with a line width of 10 μm and an aspect ratio of 1.0 is formed, a conductive wiring circuit with a 10 μm line width was performed on polyimide substrate.
Polymer Preprints, Japan 2008,57, 4420.

Interfacial Characterization of Poly(methyl methacrylate) in Water
Keiji TANAKA
Department of Applied Chemistry, Kyushu University
Density profile of a perdeuterated poly(methyl methacrylate) (dPMMA) film spin-coated on a substrate in water, which is a typical “non-solvent” for dPMMA, was examined along the direction normal to the interface by specular neutron reflectivity (NR). The interface of dPMMA with water was diffuse in comparison with the pristine interface with air. Interestingly, the dPMMA film was composed of a swollen layer and the interior region, which also contained water, in addition to the diffused layer. To conserve mass, the swelling of the film by water is accompanied by an increase in the film thickness. The change in the film thickness estimated by NR was in excellent accord with the result of direct observation using atomic force microscopy (AFM). The modulus of dPMMA in the vicinity of the water interface was also examined on the basis of force-distance curves measured by AFM. The modulus decreased closer to the outermost region of the film. The extent to which the modulus decreased in the interfacial region was consistent with the amount of water sorbed into the film.
Polymer Preprints, Japan 2008, 57, 3616.

Recycling of Waste Plastics.Energy Recovery or Material Recovery?
Masaru TANAKA
Tottori University of Environmental Studies
Now, the technologies can control dioxins under the emission standard. The Tokyo Metropolitan waste management council has proposed to specify waste plastic as not suitable waste for landfill disposal. Waste plastic management method will shift to incineration with energy recovery or material recovery. Plastic recycling method includes material recovery and energy recovery. In Containers and Packaging Recycling Laws, material recovery is given the highest priority, but the material recovery might not contribute to the natural resource conservation. It is necessary to consider the trade-off between environmental aspect and economical aspect. The evaluation tool like a Life Cycle Assessment (LCA) was developed and applied for the O city. The result is shown.
Polymer Preprints, Japan 2008, 57, 5230.

Electrospraying-Based Materials for Water, Air, Energy, and Sustainable Earth
Akihiko TANIOKA*, Hidetoshi MATSUMOTO, Department of Organic and Polymeric Materials,Minoru ASHIZAWA, and Kazuma TSUBOI
Tokyo Institute of Technology
Field-induced or injected charges in liquids interact with an external electric field and cause liquids to move, break into drops or spray into jets or strings of fine droplets. The ability of electrostatic spraying to continuously generate very small and uniform particles and fibers makes it into one of the important tools of polymer- based nanotechnology. Electrosprayed materials with nanomicroscaled structure have recently attracted much attention for applications such as high- performance filter media for gases and liquids, batteries and cells, and energy-conserving optical and electronic devices.
Polymer Preprints, Japan 2008, 57, 3381.

Formation of Polymer Spherulites:Spontaneous Gradient Field
Akihiko TODA
Graduate School of Integrated Arts and Sciences, Hiroshima University
When crystallized from the melt, a higher-order structure of polymer crystallites evolves as a spherulite with radiating and space filling branches of chain folded lamellar crystallites. The mechanism of branching and re-orientation of lamellar crystals is the most important issue to be clarified. We suggest the important role of the coupling of the re-orientation by surface stresses and an instability-driven branching with spontaneous gradient field. We examined polyethylene (PE) banded spherulites and polybutene-1 non-banded spherulites: the higher-order structure, the size of the building blocks, i.e. the width of lamellae, and the crystal growth rate. Temperature dependences suggested the instability-driven branching and the molecular weight dependences of polyethylene suggested the instability by the pressure gradient in the melt due to density difference between the crystal and the melt.
Polymer Preprints, Japan 2008, 57, 3523.

Composite Formation of Carbon Nanotubes with Fullerenes and Their Photoelectrochemical Properties
Tomokazu UMEYAMA,* Noriyasu TEZUKA, Yoshihiro MATANO, and Hiroshi IMAHORI
Department of Molecular Engineering, Graduate School of Engineering,
Kyoto University
Novel nanocarbon composites of fullerene (i.e., C60) and highly soluble, chemically functionalized SWNT (f-SWNT) have been prepared in the mixed solvent of o-dichlorobenzene and acetonitrile. Transmittance electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that f-SWNT bundles were covered with layers of C60 molecules during the clusterization. The composite film electrophoretically deposited onto a nanostructured SnO2 electrode exhibited an incident photon-to-photocurrent efficiency as high as 18% at 400 nm under an applied potential of 0.05 V vs. SCE. The highly aligned structure of C60 molecules on f-SWNT can rationalize the efficient photocurrent generation. The results obtained here will provide valuable information on the design of carbon nanotubebased molecular devices.
Polymer Preprints, Japan 2008, 57, 2502