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Tadahisa Iwata, Jun-ichi Azuma, Keizo Okamura, Fumio Tanaka
1991 Volume 47 Issue 8 Pages
379-383
Published: August 10, 1991
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The conformation of two regio-selectively substituted cellulose esters, cellulose propionate diacetate (CPDA, 2, 3-di-
O-acetyl-6-
O-propionyl cellulose) and cellulose acetate dipropionate (CADP, 6-
0-acetyl-2, 3-di-
O-propionyl cellulose), has been investigated through X-ray and electron diffraction methods. CPDA crystallizes forming an orthorhombic unit cell with dimensions
a=1.358nm,
b=2.221nm and
c (fiber axis)=1.044nm. The unit cell of CPDA has three sets of twofold screw axes parallel to the three orthogonal crystallographic axes, and the space group of CPDA is most likely P2
12
12
1. On the other hand, CADP crystallizes as a monoclinic unit cell with dimensions
a=1.108nm,
b=1.536nm,
c (fiber axis)=1.500nm and γ=90°. CADP has a threefold screw symmetry along the molecular axis as does cellulose tripropionate (CTP). The space group is P2
1 with
b as the unique axis.
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Masao Sumita, Kazuya Sakata, Shigeo Asai, Keizo Miyasaka, Hideaki Naka ...
1991 Volume 47 Issue 8 Pages
384-387
Published: August 10, 1991
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The distribution state of carbon black (CB) was observed in polymer blends by scanning (SEM) and transmission (TEM) electron microscopies. CB distributed unevenly in the polymer blend. There were two types of distribution. In the first type, CB particles were predominantly distributed in one phase of the blend matrix. In the second type, the fillers concentrate at the interface of two polymers. This heterogeneous distribution of fillers in a polymer blend matrix was mainly due to the difference in affinity of CB particles to each component of the polymer blend. In high density polyethylene/polypropylene blend, CB particles were mainly located in the polyethylene phase. When oxidated CB particles were used, however, they were concentrated at the interface of the two polymer phases.
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Shigeo Hirose, Tatsuko Hatakeyama, Hyoe Hatakeyama
1991 Volume 47 Issue 8 Pages
388-391
Published: August 10, 1991
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Liquid crystalline properties of copolyester having dimethoxyphenylene groups, poly (oxy 2, 6-dimethoxy-1, 4-phenylene-oxy-4, 4′-biphenyldicarbonyl-
co-terephthaloyl) were studied by polarizing microscopy and differential scanning calorimetry. The typical nematic pattern was observed at 600 K by polarizing microscopic measurement. The copolyester was found to form the glassy liquid crystalline state when the sample was quenched from the liquid crystalline state.
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Yoji Maeda
1991 Volume 47 Issue 8 Pages
392-396
Published: August 10, 1991
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Morphological observation of the texture of thermotropic polyester, poly (4, 4'-dioxy-2, 2'-dimethylazoxybenzene alkanedioyl) has been performed by using a polarized microscope equiped with a hot stage. The observation showed that the oily streak texture of the nematic phase changes dramatically in the nematic-isotropic biphasic region.
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Toshisada Takahashi, Chang Fa Xiao, Kensuke Sakurai
1991 Volume 47 Issue 8 Pages
397-402
Published: August 10, 1991
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High performance fibers with high modulus and high strength have been reported to exhibit poor compressional properties. The present work is concerned with the axial compressional behavior of liquid crystalline wholly aromatic copolyester (ACPE) fiber (Ekonol type). ACPE fibers were embedded in 2-hydroxypropyl methacrylate and were compressed manually with a vise. Compressed ACPE fibers taken out from the resin block were examined by polarizing optical microscopy (POM) and scanning electron microscopy. In the initial stage of compression, kink bands are formed on the surface of ACPE fibers at an angle of ca 60° to the fiber axis. It was confirmed by POM that all molecular chains within the band were sharply bent from their original direction by an angle of 30-40°. It can be predicted that two slip systems, (110) 〈001〉 and (100) 〈001〉, are responsible for the formation of the kink band. With progressive compression, new kink bands were formed near the kink bands that were formed in the initial stage of the compression, indicating that compressional stress is concentrated at regions near the kink bands. When compressed further, massive lateral displacement occurred from place to place along fiber axis and finally ACPE fiber was almost squeezed out of shape. Intermicrofibrillar slip played an important role at this stage of compression.
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Mutsumasa Kyotani, Akira Kaito, Kazuo Nakayama
1991 Volume 47 Issue 8 Pages
403-406
Published: August 10, 1991
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The morphological properties of the phase of a liquid crystalline rigid-chain polymer (LCP) in extruded sheets and strands of the blend with poly (ethylene terephthalate) (PET) were investigated by scanning electron microscopy and X-ray diffraction. The LCP phase was extracted from sheets and strands of the LCP/PET blend with trifluoroacetic acid at room temperature. The LCP content and the extension ratio of sheets and strands of the blend affected the structures of the LCP phase in the blend. The LCP component tended to form spherical or elliptical structures in the blend strands of lower LCP content and at lower extension ratios. On the other hand, networks of thin LCP fibrils were obtained in the blend strands of higher LCP content and at much higher extension ratios.
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Toshio Kunugi, Tadayuki Harada, Kazuhiro Nakazawa, Kazuo Miyake, Akihi ...
1991 Volume 47 Issue 8 Pages
407-411
Published: August 10, 1991
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Nylon 6 single crystals grown from dilute polymer solutions at room temperature by a sol-vent-evaporation method were briefly reported. The shape, size, and crystal habit of the crystals obtained were examined by an optical microscope, a polarizing optical microscope, and a SEM microscope. The spherulites, long crystals, romboid crystals, twin, hexagonal crystals, and octahedral crystals were found in shapeless precipitates.
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Nobuo Donkai, Hiroshi Hoshino, Kanji Kajiwara, Takeaki Miyamoto, Hiros ...
1991 Volume 47 Issue 8 Pages
412-416
Published: August 10, 1991
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Lyotropic liquid crystals formed by inorganic rigid rod molecules, imogolite, were observed directly by transmittion and scanning electron microscopies.
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Tatsuko Hatakeyama, Nursjamsu Bahar, Hyoe Hatakeyama
1991 Volume 47 Issue 8 Pages
417-420
Published: August 10, 1991
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The liquid crystalline properties of the water-Li, -Na, -K, -Cs, -Mg, -Ca and -Ba carboxymethylcellulose (CMC) systems with water contents (W
c=water/dry CMC, g/g) of ca. 0 to 3.5 were investigated by polarizing light microscopy and differential scanning calorimetry. The above systems formed the nematic structure in a temperature ranging from 270K to 340K in a W
c ranging from ca. 0.6 to 2.5.
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Kunio Nakamura, Tatsuko Hatakeyama, Hyoe Hatakeyama
1991 Volume 47 Issue 8 Pages
421-423
Published: August 10, 1991
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The formation of the liquid crystalline state in the water-sodium alginate system was investigated by polarizing microscopy. The liquid crystalline state was observed in the water-sodium alginate system having high molecular weight and high guluronic acid content. The rate of liquid crystallization in this system was markedly slower than that of other polyelectrolytes.
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Hae Jinn Kim, Munenori Sakamoto
1991 Volume 47 Issue 8 Pages
424-427
Published: August 10, 1991
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Morphology of aggregates separated from dilute aqueous solutions of hydrogen-bonding polymer comlex systems by rapid freezing at -78°C followed by defreezing was studied by scanning electron microscopy. Polymer complexes with weak cooperative interaction gave no precipitates and those with moderate interaction yielded aggregates in fibrous form. Polymer complexes with strong interaction gave aggregates of network structure which was probably formed from the modulated structure developed by spinodal decomposition during the rapid freezing treatment of the solution.
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Namiko Miyata, Isao Sakata
1991 Volume 47 Issue 8 Pages
428-433
Published: August 10, 1991
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The microscopic structures of the graft copolymers of hydroxyethylcellulose (HEC) containing partially hydrolyzed polyacrylamide (P-Hyd-PAM) or poly (methyl acrylate) (P-Hyd-PMA) and poly (2-dimethyl aminoethyl methacrylate) (PDM) synthesized as super water-absorbents and those of their gels were examined. The surfaces of HEC-P-Hyd-PAM, HEC-PDM and their gels were composed of granular and network structures, respectively, whereas those of HEC-P-Hyd-PMA and its gel were composed of a rod-like structure and an aggregate structure, respectively. The relation between their structures and some properties was examined.
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Carolina E. Tayag, Yasushi Watanabe, Tatsuko Hatakeyama
1991 Volume 47 Issue 8 Pages
434-438
Published: August 10, 1991
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Structure and properties of five kinds of cellulosic raw fiber obtained from abaca (musa tex-tiles nee), banana (musa vavendishii), kenaf (sibiscus cannabinus linn), maguey (agave cantala roxb) and ramie (boehmeria nivea) were investigated by polarizing light microscopy, scanning electron microscopy, X-ray diffractometry and gravimetric water-sorption measurement. The crystallinity (
x) of the fibers was ranged from 47 to 61% for raw fibers and from 52 to 66% for fibers treated by aqueous solution of NaOH. The number of water molecules attached to the fibers were found to decrease with increasing
x, indicating that water molecules were sorbed on the hydroxyl groups in the amorphous region of cellulose.
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Takashi Watanabe
1991 Volume 47 Issue 8 Pages
439-441
Published: August 10, 1991
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Poly (p-phenylene terephthalamide) fibers (Kevlar 29) were degraded by
A. flavus on agar slant medium. The biodegradation resulted in the increase in diameter and the bending of fiber, but did not cause complete disintegration of fibers. The aspects of the biodegradation of Kevlar 29 were remarkably different from those of Kevlar 49.
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Fumi Masuko, Ken-ichi Furuhata, Munenori Sakamoto
1991 Volume 47 Issue 8 Pages
442-446
Published: August 10, 1991
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Merino wool fabrics were treated with dilute KCN in water/organic solvent mixtures, and resulting morphological changes were studied by scanning electron microscopy. Longitudinal striations were differentially formed on the orthocortex side of the fiber surface.
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Hirokazu Kimura, Hiroshi Sakabe, Takashi Itoh, Takashi Konishi
1991 Volume 47 Issue 8 Pages
447-451
Published: August 10, 1991
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Morphology of poly (β-alanine) crystal, which was formed through the thermal solid state polycondensation procedure from β-alanine monomer single crystal, was observed mainly by means of scanning and transmission electron microscopy. In the early stage of the polymerization reaction at 150°C, the surface of the specimen was found to be covered by the aggregation of the rod-like materials (ca. 1μm thick and 10μm long). The fibrillar structure was observed on the surface in the final stage of the reac-tion. Each fibril is about 100nm in diameter. Decreasing the reaction temperature to 130°C, it was found on the basis of the X-ray diffraction results that the direction of the polymer chains corresponds to the long axis of the monomer molecules in the original monomer single crystal. There were two principle directions for the morphological fiber axis and the fibrils overlapped each other crosswise.
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Takeshi Fukuda, Makoto Sugiura, Akihiko Takada, Takahiro Itoh, Yung-Da ...
1991 Volume 47 Issue 8 Pages
452-455
Published: August 10, 1991
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Acylation or regio-selective alkylation of cello-and/or chito-oligosaccharides provides a new family of thermotropic liquid crystals. Some of the mesophase textures and thermal properties exhibited by these compounds were presented.
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Ryu Ogawa, Manabu Sato, Yoshiaki Miura, Seiichi Tokura, Mitsuo Takai
1991 Volume 47 Issue 8 Pages
456-460
Published: August 10, 1991
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Acetobacter xylinum strains produced bacterial cellulose incorporated
N-acetyl-glucosamine (GlcNAc) in molecule (N-AcGBC) in medium containing GlcNAc. The profiles of the N-AcGBC and normal bacterial cellulose (BC) microfibrils treated with cellulase or lysozyme were observed by scanning electron microscopy. After the treatment with lysozyme, the morphological changes of the N-AcGBC microfibrils of pellicle or homogenates were found. Cellulase did not make any difference between BC and N-AcGBC.
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1991 Volume 47 Issue 8 Pages
465
Published: 1991
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SATOMI TSUNODA
1991 Volume 47 Issue 8 Pages
P422-P424
Published: August 10, 1991
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TOSHIKATSU NISHIMURA
1991 Volume 47 Issue 8 Pages
P425-P429
Published: August 10, 1991
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TOKUROH KIDA
1991 Volume 47 Issue 8 Pages
P430-P434
Published: August 10, 1991
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NAOTO MIFUNE, NAOYUKI YAGUCHI
1991 Volume 47 Issue 8 Pages
P435-P441
Published: August 10, 1991
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SHUZO TAKAHASHI
1991 Volume 47 Issue 8 Pages
P442-P445
Published: August 10, 1991
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YUTAKA NAGANO
1991 Volume 47 Issue 8 Pages
P446-P449
Published: August 10, 1991
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TADAO MORISHITA
1991 Volume 47 Issue 8 Pages
P450-P453
Published: August 10, 1991
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Makoto Sunaga
1991 Volume 47 Issue 8 Pages
P454-P457
Published: August 10, 1991
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