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Vol. 60, No. 3, March (2011)

An Innovative Liquid Crystal Display Material: Polymer-Stabilized Blue Phase
Hirotsugu KIKUCHI
Institute for Materials Chemistry and Engineering, Kyushu University

The polymer-stabilized blue phases were prepared by photo-polymerizing monomers in a liquid crystalline blue phase under varying photo-polymerization conditions such as the wavelength of light source and the polymerization temperature and the kind of monomers. A fast electro-optical response time, less than 1 ms, and a high contrast ratio, larger than 1000, were achieved with the polymer-stabilized blue phases when the wavelength of light source and the copolymerization reactivity ratio of two different monomers were optimized. We successfully developed an innovative liquid crystal display material by using the polymer-stabilized blue phases whose display speed is more than ten times faster than that of conventional liquid crystal display materials and alignment processes such as rubbing are not necessary.
Polymer Preprints, Japan 2010, 59, 1619.

Three-Dimensional (3D) Imaging Technique and Polymer Hierarchical Morphologies
Hiroshi Jinnai1,2
1Department of Macromolecular Science and Engineering, Graduate School of Science and Engineering, Kyoto Institute of Technology 2WPI Advanced Institute for Materials Research (WPI-AIMR), Tohoku University
We discuss recent developments of various types of 3D imaging techniques for polymer research. Deformation mechanism of a fiber-reinforced plastic (FRP) was examined at the same volume of specimen by X-ray CT. Rearrangement of fibers and void formation, together with the mechanical properties of the material, has been simultaneously observed. Figure shows 3D images of FRP under uniaxial extension. The strains are (a) 0 (quiescent state), (b) 20%, and (c) 60%. Gray rods and red region are fibers and voids, respectively. On the other hand, in much smaller scale, a 200 kV TEM with new electron optics enables us to image a micrometer thick ABS resin. The meso-scale 3D observation technique finally fills the existing spatial gap in 3D imaging, offering an unique opportunity to study hierarchical polymer (nano)structures, and to establish "structure-property" relationship in polymer materials.
Polymer Preprints, Japan 2010, 59, 2175.
Macromolecules (Perspective), 2010, 43, 1675.

Chemical Synthesis of Glycoproteins Having Human Complex Type Oligosaccharides
Yasuhiro KAJIHARA
Department of Chemistry, Osaka University
Oligosaccharides linked to protein play a very important role in many biological events such as cell-cell interaction, transportation, protein lifetime in blood, protein conformation, and antigenicity. Recently, the chemical synthesis of glycoproteins as well as glycopeptides has been developed. We recently demonstrated synthesis of two bioactive glycoproteins, monocyte chemotactic protein-3 and EPO analogues. In terms of the EPO analogue having two complex-type biantennary sialyloligosaccharides, native chemical ligation between the glycosylated peptide athioester (1-32 amino acid residues) prepared by chemical synthesis and the peptide (33-166 amino acid residues) prepared from E. coli expression successfully resulted in a whole EPO polypeptide chain having two sialyloligosaccharides. Subsequent folding experiments enabled us to obtain EPO analogue exhibiting cell proliferation activity in vitro.
Polymer Preprints, Japan 2010, 59, 2217.
Angew. Chem., Int. Ed. 2009, 48, 9557.

Systematic Structural Analyses of Glycoconjugates: NMR and Sugar Library Approaches
Koichi KATO1-4
1National Institutes of Natural Sciences, 2Nagoya City University, 3Ochanomizu University, 4GLYENCE Co., Ltd.
More than half of proteins in nature have been predicted to be modified with sugar chains, which not only confer solubility and structural integrity of proteins but also regulate molecular recognition events mediating cell-cell communication and viral infections. For better understanding of such glycoconjugate functions, detailed structural analyses of their glycans are essential but extremely difficult because of the heterogeneous and flexible properties of the sugar chains. In view of this situation, we have been developing a systematic method for the elucidation of the underlying mechanisms of the glycan functions by combined use of NMR spectroscopy and sugar library techniques. The sugar library, constructed based on themulti-dimensional HPLC database 'GALAXY', can be a useful tool for comprehensive analyses of sugar-protein interactions. Ultra-high field NMR techniques, in conjunction with stable isotope labeling of the sugar chains, provide valuable information on conformations, dynamics, and interactions of glycoconjugates at atomic level. These approaches will open up new possibilities for structural studies of glycoconjugates of clinical interest.
Polymer Preprints, Japan 2010, 59, 2220.
Prog. Nucl. Magn. Reson. Spectrosc., 2010, 56, 346.

Multivariate Analysis of 13C NMR Spectra of MMA-TBMA-HEMA Terpolymers
Koichi UTE
Department of Chemical Science and Technology, The University of Tokushima
NMR signals from each group in multi-component copolymers often exhibit superposed splitting due to monomer sequences and configurational sequences, and thus assignment of individual resonance peaks is troublesome. As an approach to obtain quantitative information from NMR spectra of those copolymers without assigning resonance peaks, methods of multivariate analysis were applied to the analysis of 13C NMR spectra of terpolymers of MMA, tert-butyl methacrylate (TBMA) and 2-hydroxyethyl methacrylate (HEMA) prepared by radical polymerization at 80 oC. The spectral pattern of the ternary system was explained well with the first, second and third principal components (PC1, PC2, PC3). PC1 and PC2 showed a relationship to chemical composition whereas PC3 showed a relationship to the heterogeneity of monomer sequences.
Polymer Preprints, Japan 2010, 59, 2214.

New Materials and Technologies for Constructing Polymer Recycling Systems
Haruo NISHIDA
Eco-Town Collaborative R&D Center, Kyushu Institute of Technology
Development of recyclable materials and their depolymerization control technologies, which are essential for constructing "a recycling-based society", are reviewed. Recently, various polymeric materials and recycling technologies have been progressing; for example, upgrade recycling of commodity resins, selective transformation of engineering plastics, selective depolymerization of various polymers in supercritical fluids, crosslinking-decrosslinking control using reversible reactions, biomass-based renewable plastics, and precise kinetic analyses of thermal degradation. These materials and technologies will require further refinement before being used practically to form part of the recycling system for containers, packages, electric household appliances, and end-of-life vehicles, all of which are operated in compliance with the recycling laws of Japan.
Polymer Preprints, Japan 2010, 59, 5317.