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Volume 42, Issue 3
Displaying 1-10 of 10 articles from this issue
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Katsuhiko NAKAMAE, Tsukasa OCHIUMI, Masaki TSUKADA, Toshiyuki SEKIDO, ...1985 Volume 42 Issue 3 Pages 143-149
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe effect of coagulation temperature on the structure and properties of ethylene-vinyl alcohol copolymer (EVA) membrane was investigated. Membranes were prepared at different coagulation temperatures, from 0°C to 70°C. The water flux and the pore size increased with increasing the coagulation temperature up to 55°C and then decreased to 70°C. The membranes prepared between 0°C and 20°C has a finger-like void; the coagulation was very slow, owing to the higher viscosity of the polymer solution at low temperature. On the other hand, the membrane prepared above 50°C has small spherical micelles in the pore cell walls because of the lower viscosity of solution: above 70°C, the membrane tended to be plastsized by hot water.View full abstractDownload PDF (1394K) -
Hiroshi TAODA, Kiyoshi HAYAKAWA, Kaoru KAWASE, Mineo KOSAKA1985 Volume 42 Issue 3 Pages 151-158
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to estimate the extent of thermal oxidative aging of polyethylene pellets used as a latent-heat-type thermal storage material, the deterioration of polyethylene pellets was investigated by applying the following heating-cooling cycle, which simulates the daily insolation over 6 months: that is, 8-hour holding at 150°C as the highest temperature in a day followed by 5-hour holding at 30°C as the lowest one. The degradation, e. g., the lowering of heat of crystallization and of crystallization temperature, is thought to be caused by both the decrease in molecular weight of polyethylene due to thermal oxidative decomposition and the crosslinking between produced radicals. With the increase in the degree of crosslinking and branching in a molecular-chain which has low bond dissociation energy, thermal-deterioration of polyethylene proceeded more rapidly. The deterioration depended mainly on the accumulated holding time at the highest temperature, and this was shown by comparison with a continuous heating experiment at the highest holding temperature, 150°C. Polyethylene pellets can endure long periods of practical heat-cycling as a thermal storage material if they are treated with radical scavengers and if the degrees of their crosslinking are properly controlled.View full abstractDownload PDF (1468K) -
Toshio KITAO, Toshihiro FUNABIKI1985 Volume 42 Issue 3 Pages 159-166
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAn unoriented glassy poly (ethylene terephthalate) fiber, melt-spun at 285°C and immediately quenched in cold water, was drawn at temperatures below its Tg. The cold drawing at 50°C or higher gave transparent, highly-oriented, and lightly crystalliezed fibers, whereas that at 40°C or lower resulted in crazing of the fibers. Then the fibers drawn at 50°C to the natural draw ratio (4.2 times) were subjected to the annealing in two different procedures; i. e., annealing at constant length and that under tension. Comparative studies of the annealed fibers revealed that the latter was more effective to improve the mechanical properties than the former. A drastic increase in tensile modulus was found for the fiber annealed at 180°C under tensions. For instance, the fiber drawn at 50°C and annealed at 180°C for 10 min under the tension of 13 kg/mm2 had an extremely high modulus of 26 GPa, while the tensile strength was only 0.6 GPa.View full abstractDownload PDF (2027K) -
Tohru SUZUKI, Tsugikazu TOMONO, Masahisa IKEMI, Shoji KIGOSHI, Isao SH ...1985 Volume 42 Issue 3 Pages 167-173
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe heat aggregation of human immunoglobulin G (IgG) was investigated by high performance size-ex-clusion chromatography, complement fixation assay, and spectrophotometry of circular dichroism (CD) and fluorescence using a hydrophobic microenvironment probe, 8-anilinonaphthalene-1-sulfonate (ANS). Heat treatment of the monomeric IgG produced a certain amount of the aggregates, which strongly fixed complements, and also induced an enhanced complement fixing ability of the monomeric molecule. During the aggregation was observed a remarkable alteration in the tertiary structure of IgG molecule which imparted the hydrophobicity to their molecular surfaces. Negligible CD and ANS-fluorescence alteration in the monomeric IgG during the heating implied no contribution of aromatic aminoacid residues to the conformational alteration which enhanced complement fixation. Negligible alteration in the dimeric molecule explained the reversibility of the dimerization. The location of conformational change on the Fab region suggested a spherical micelle like structure for the heat aggregates, in agreement with both observations of the higher intrinsic aggregability of the Fab portion than the pFc′ portion and of the insolubility of the aggregates derived from the proteolytic fragments.View full abstractDownload PDF (1321K) -
Tohru SUZUKI, Tsugikazu TOMONO, Shoji KIGOSHI, Shigeru IGARASHI, Isao ...1985 Volume 42 Issue 3 Pages 175-180
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe effects of water-soluble synthetic polymers on heat aggregation of immunoglobulin G (IgG) and accompanied complenent fixation were investigated. Heat treatment of IgG in the presence of 2-hydroxyethyl methacrylate (HEMA) -N-vinyl-2-pyrrolidone random, HEMA-acrylamide random, and HEMA-ethyleneoxide (EO) block copolymers led suppression of heat-induced complement fixing ability of IgG, the extent of which was enhanced as increasing hydrophobic HEMA composition in the copolymer. While, propyleneoxide (PO) -EO block copolymers showed remarkable suppression effect with increase of hydrophilic EO content. In HEMA EO graft copolymer system, the formation of polymolecular micelle of the coplymer resulted in a loss of suppression effect on the heat aggregation of IgG. That is, the proper hydrophobicity of water-soluble polymer was an important factor for suppression of heat-induced complement fixing ability. Addition of the water-soluble polymer, especially which hardly segregated from IgG molecule, resulted in change of aggregate structure of IgG and also in suppression of complement fixing ability.View full abstractDownload PDF (1096K) -
Masaru MIYA, Reikichi IWAMOTO, Koji OHTA, Seiichi MIMA1985 Volume 42 Issue 3 Pages 181-189
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSInvestigation has been made on the method of N-acetylation of chitosan in the form of solid films. The acetylation was carried out by reacting with acetic anhydride in water-methanol mixed solvent. In the solvent, increase of water content accelerated the acetylation rate, although the content was kept below 50% to prevent the distortion of the treated film. The degree of acetylation was determined by infrared spectroscopy with the use of the absorbance ratio A1554/A897. Examination was also made on the effect of acetyl content in chitosan and salt formation on the reaction rate. Measurement of FT-IR-ATR spectra of the acetylated film revealed that the crystalline portion was resistant to the reaction both at the surface and in the bulk. Water content of the reaction mixture was found to play a key role to regulate the degree of acetylation of chitosan, since the content determined the fraction of crystalline portion that was destroyed by water to be easily susceptible to the reaction.View full abstractDownload PDF (1480K) -
Mikio TAKESHIMA, Nobuhiro FUNAKOSHI1985 Volume 42 Issue 3 Pages 191-198
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThis study clarifies the effects of molding conditions on the degree and distribution of frozen molecular orientations for injection-molded polycarbonate disks, through the measurements of the mean birefringence, heat shrinkage and density.
The mean birefringence and heat shrinkage represent the degree of frozen orientation. They increased as the gate came closer. However, they are reduced by increasing the cylinder temperature. They are almost unaffected by the mold temperature, holding pressure, injection rate and holding time. The density increased as the gate came closer and decreased as the cylinder temperature increased. The large birefringence polycarbonate disk shrinks in the diameter direction and expands in the circuit direction in the temperature range above Tg (150°C). The aging during the heat shrinkage was measured at various temperatures, both below and above Tg. The isotherms are closely superposable by horizontal shifts. The frozen orientation is formed by the back-flow of the polymer melt from the mold cavity, due to the short holding time and to the holding pressure.View full abstractDownload PDF (1456K) -
Toshihide INOUE, Hideo KOMATSU1985 Volume 42 Issue 3 Pages 199-203
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThermal properties of poly [alkylene 1, 2-bis (2, 6-dibromophenoxy) ethane-4, 4-dicarboxylate] (Polyetheresters) have been studied. The glass transition temperatures of polyether-esters are higher those of poly [alkylene 1, 2-bis (2-bromophenoxy) ethane-4, 4′-dicarboxylate]. Poly [ethylene 1, 2-bis (2, 6-dibromophenoxy) ethane-4, 4-dicarboxylate] (Br content 49.7%) are excellent flame-retardants for poly [butylene terephthalate] (PBT) etc. Self-extinguishing poly (ethylene terephtalate) (PET) / poly [ethylene 1, 2-bis (2-bromophenoxy) ethane-4, 4′-dicarboxylate] copolyester fibers and PET-poly [ethylene 1, 2-bis (2-bromophenoxy) ethane-4, 4′-dicarboxylate] blend fibers (Br content 10%) have higher Young modulus than PET fibers and excellent UV stability than PET-hexabromobenzene blend fibers (Br content 10%).View full abstractDownload PDF (734K) -
Toshio TAKEMURA, Takashi MARUYAMA, Seizo NAKASHIO1985 Volume 42 Issue 3 Pages 205-210
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe oxidative polymerization of 2, 6-xylenol with manganese complex catalyst composed of manganese chloride, ethanolamine and methanol was studied on the influence of phenol derivatives such as o-, m-, p-cresol and 2, 5-xylenol, reducing agent, peroxide, and metal halides. m-Cresol and p-cresol did not show reactivity as monomer but o-cresol and 2, 5-xylenol participated in oxidative polymerization as monomer, reacting at the 4-position as well as the 6-position. The polymerization under the conditions of 2, 5-xyleno1/2, 6-xylenol=50/50 gave the polymer in 86% yield having intrinsic viscosity up to 0.50 dl/g. In case of o-cresol, a polymer, partially gelatinized, was obtained in 80% yield at the same comonomer ratio. The intrinsic viscosity of the soluble part was 0.20 dl/g. Methyl group at the 5-position of 2, 5-xylenol was effective to depress the coupling reaction at the 6-position. Furthermore reducing agents such as zinc powder inhibited the polymerization, although the effect was much smaller in the presence of a peroxide. While SnCl4 inhibited the polymerization, ZnCl2 disclosed the effect to increase the yield and intrinsic viscosity of the polymer.View full abstractDownload PDF (956K) -
Katsuhiko NAKAMAE, Takashi NISHINO, Katsuhiko HATA, Tsunetaka MATSUMOT ...1985 Volume 42 Issue 3 Pages 211-217
Published: March 25, 1985
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSElastic moduli of the amorphous region (Ea) of atactic polystyrene (PS), which is a typical amorphous polymer, were measured by X-ray diffraction. The measurements were carried out to detect the shift of amorphous halo owing to the stress applied. Ea were reflected by the intermolecular cohesive energy, they ranged from 1.9×104kg/cm2 to 2.3×104kg/cm2 for four kinds of PS with different thermal histories. From the data of DSC thermograms, densities and crystal modulus, these Ea values could be explained from the viewpoint of molecular packing. Specimen moduli values included both the intermolecular cohesive energy and the extension based on the conformational change of the molecules.View full abstractDownload PDF (1586K)
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