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Volume 30 (2003)
- Issue 5 Pages 224-
- Issue 4 Pages 154-
- Issue 3 Pages 98-
- Issue 2 Pages 54-
- Issue 1 Pages 2-
Volume 30, Issue 4
Displaying 1-9 of 9 articles from this issue
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Thermal Properties of Epoxy Resins from Ester-Carboxylic Acid Derivatives of Mono- and DisaccharidesShigeo Hirose, Tatsuko Hatakeyama, Hyoe Hatakeyama2003 Volume 30 Issue 4 Pages 154-160
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSMono- and disaccharides (SAC) such as glucose (Glc), fructose (Frc) and sucrose (Suc) were dissolved in ethylene glycol and each of the obtained mixture was reacted with succinic anhydride to form a mixture of ester-carboxylic acid derivatives (SAC-polyacid, SACPA). Ethylene glycol-polyacid (EGPA) was also prepared from ethylene glycol. Each of the obtained mixtures of ester carboxylic acid derivatives was reacted with ethylene glycol diglycidyl ether in the presence of a catalytic amount of dimethylbenzylamine to form ester-epoxy resins. The molar ratios of epoxy groups to carboxylic acid groups ([EPOXY]/[ACID] ratios, mol mol-1) were varied from 0.5 to 1.3. The contents of SACPA in the mixture of SACPA and EGPA were also varied from 0 to 100%. Thermal properties of epoxy resins were studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). Glass transition temperatures (Tg's) of epoxy resins showed a maximum value of -8.1°C when [EPOXY]/[ACID] ratio was 1.0. Tg's increased with increasing SACPA contents suggesting that saccharides act as hard segments in epoxy resin networks. Thermal decomposition temperatures (Td's) of epoxy resins slightly decreased with increasing SACPA contents, while mass residue at 500°C increased with increasing SACPA contents.View full abstractDownload PDF (1245K) -
Takeshi Yamada, Takafumi Watanabe, Hirohisa Yoshida2003 Volume 30 Issue 4 Pages 161-166
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSTemperature changes of orientation functions for uniaxial drawn polypropylene (iPP) were evaluated by the simultaneous DSC-XRD and DSC-FTIR methods. In order to evaluate the orientation function with high time resolution, two-dimensional CCD detector and MCT detector were used for XRD and FTIR measurements, respectively. The crystallographic and conformational orientation functions of crystal c-axis were obtained from two-dimensional XRD profiles and polarized FTIR spectra, respectively. The uniaxial drawn polypropylene showed the melting peak with a shoulder at lower temperature side. The crystallographic orientation function of c-axis decreased and the conformational orientation function of c-axis increased at temperature below the melting. This fact suggested that the melt-recrystallization was brought into the re-organization of drawn iPP.View full abstractDownload PDF (1964K) -
Ling Sun, Yukiko Kondo, Koji Kirisawa, Junko Morikawa, Toshimasa Hashi ...2003 Volume 30 Issue 4 Pages 167-172
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe oxyluminescence method was applied to fabric and subjected to a constant heating rate in air. Compared with conventional thermogravimetry, the luminescence was observed in a temperature region that is about 150°C lower than conventional standards. This temperature region corresponds to the early stage of oxidation and degradation of the selected materials. This method was used on each silk sample according to the apparent activated energy distribution, spectrum of luminescence and contrast with IR absorption spectrum. After thorough analysis, it was determined that the oxyluminescence is particularly useful in investigating the oxidation and degradation processes of polymeric materials, especially when compared with conventional method such as TGA and FT-IR.View full abstractDownload PDF (1370K) -
Takahiro Sato2003 Volume 30 Issue 4 Pages 173-179
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSVarious statistical thermodynamic theories have been presented so far to understand thermodynamic properties of polymer solutions. The basic model and assumptions as well as deficiency of the theories are explained. The famous Flory-Huggins theory is favorably compared with experiment only at high polymer concentrations. The cluster expansion theory for polymer systems successfully calculates the second virial coefficient in dilute polymer solutions but not the higher virial coefficients. The renormalization-group theory makes possible the calculations of the higher virial coefficients, but it is not applicable to concentrated polymer solutions. A perturbation theory extended to polymer solutions is favorably compared with experiment except for high-molecular-weight flexible polymer solutions with low concentrations.View full abstractDownload PDF (1587K) -
Shingo Tsubouchi, Tôru Kyômen, Mitsuru Itoh2003 Volume 30 Issue 4 Pages 180-188
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSIt has been reported that the intermediate spin state becomes the ground state of Co ions in perovskite-type cobalt oxides and that peculiar spin-crossover phenomena occur in the oxides. The experimental facts and their interpretation on the spin state and the spin crossover phenomena of LaCoO3 and Pr0.5Ca0.5CoO3 are introduced in comparison with those in spin-crossover complexes. The spin crossover phenomena of the perovskite-type cobalt oxides are correlated with the change in electrical resistivity. It has been considered that the correlation originates from the strong Co 3d eg-O2p hybridization connecting with the intermediate spin state. In addition, many facts imply that the roles of vibrational and magnetic energies to the spin-crossover phenomena are different between perovskite-type cobalt oxides and spin-crossover complexes.View full abstractDownload PDF (1671K) -
Ryo Murakami, Youichi Takata, Makoto Aratono2003 Volume 30 Issue 4 Pages 189-195
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe thermodynamic equations that take account of aggregate formation in the oil solutions were developed to analyze the enthalpy of mixing of an oil soluble substance with solvent oil measured by the isothermal titration calorimetry (ITC). They were applied to the ITC results of the oleyl alcohol-cyclohexane and -benzene mixtures. The enthalpy of aggregate formation of the alcohol molecules was obtained as -16∼-20kJ mol-1 and thus the hydrogen-bonded cyclic tetramer was supposed to be a predominant aggregate for the cyclohexane system. On the other hand, the corresponding enthalpy of the benzene systems was -2kJ mol-1 and thus a hand drum-shaped aggregate or normal micelle with small aggregation number and a large quantity of solvation of the OH group was suggested.View full abstractDownload PDF (1601K) -
Toshiharu Takizawa2003 Volume 30 Issue 4 Pages 196-204
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSHeat treatments produce the ubiquitous endothermic transitions in the differential scanning calorimetry of biological substance-water systems. The transitions appear at the temperature ranges from 20 to 60°C depending on both of the temperature and the duration of the heat treatments. The transition enthalpies per gram of water in the sample lie between 2 to 20Jg-1 for the systems containing not so much water. These ubiquitous phenomena are explained as a memory effect of various kinds of weak hydrogen bonds formed in the biological substance-water system by the heat treatments.View full abstractDownload PDF (1923K) -
2003 Volume 30 Issue 4 Pages 205
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (126K) -
M. Momota, Y. Iwata2003 Volume 30 Issue 4 Pages 206
Published: August 31, 2003
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (189K)
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