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Volume 69, Issue 4
Displaying 1-8 of 8 articles from this issue
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Original Papers
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Hironori OSHIRO, Akihiko KONO, Tetsuya DANNO, Hideo HORIBE2012 Volume 69 Issue 4 Pages 135-141
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSThis paper discusses the fabrication method of Poly(vinylidene fluoride) (I) crystal having excellent dielectric properties. We tried to control the crystal structure of PVDF in the blend films of PVDF and Poly(methyl methacrylate) (PMMA) prepared by solvent casting. PVDF/PMMA = 60/40 wt.% blend was dissolved in DMF solvent at 120°C. After casting, the PVDF/PMMA blend films were baked at 150°C (B). Each film was quenched (Q) from melting state and then was annealed at 120°C (QA). As a result, we demonstrated that PVDF (I) crystal grows preferentially under the existence of PMMA. That the crystallization speed of the quenched and annealed PVDF/PMMA blend films (QA) with the blend ratio of PVDF/PMMA = 60/40 wt.% is comparatively slow and forms the PVDF (I) crystal.View full abstractDownload PDF (2530K) -
Yukinobu MURATA2012 Volume 69 Issue 4 Pages 142-148
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSDielectric properties were investigated for quenched films of polyamides consisting of piperazine and aliphatic dicarboxylic acids with the number of carbon atoms from 7 to 10 over a frequency range from 25 Hz to 1 MHz, at temperatures from 200 to 450 K. The α and γ relaxations were observed in decreasing order of temperature. The α relaxation was observed at temperatures above the glass transition. Frequency dependence of dielectric constant and loss for the α relaxation was not symmetrical about the relaxation frequency and skewed toward high frequency. Values of dielectric strength of the relaxation were 10 to 13 for polyamides with an odd number of carbon atoms in the dicarboxylic acids and 3.9 to 4.0 for polyamides with an even number of carbon atoms in the dicarboxylic acids. The α relaxation was related to the reorientation of the N-C=O group by the micro-Brownian motion of molecular chains. The β relaxation observed for the wet Pip9 at temperatures below room temperature was due to molecular motions of the H2O attached the C=O group. The γ relaxation observed for Pipn at lower temperatures than those for the β relaxation was related to the local molecular motions of methylene sequences.View full abstractDownload PDF (2102K) -
Takefumi NARITA, Noboru TAKAYAMA, Katsumi MIZUNO, Shinichi OHASHI, Sat ...2012 Volume 69 Issue 4 Pages 149-153
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSIn this study we investigated the effect of A.oryzae treatment of chitosan film on fibroblast adhesion. The number of fibroblast on the A.oryzae treated chitosan film was about 1.8 times higher than that on an untreated chitosan film. The surface of the A.oryzae treated chitosan film was analyzed by X-Ray photoelectron spectroscopy. The A.oryzae treatment introduced nitrogen containing and oxygen containing functional groups onto the surface of the chitosan film. The A.oryzae protein adsorbed on the chitosan film was analyzed by SDS-PAGE and proteome analysis. It was found that three proteins with molecular weights of 104 kDa (beta-glucosidase), 97 kDa (dipeptidyl-peptidase), 92 kDa (dipeptidyl-aminopeptidase) adsorbed on chitosan film, resulting in the increase in the cell adhesion on the film.View full abstractDownload PDF (1488K) -
Yuichi AOYAGI, Kiyofumi FUKASAWA, Hiroaki KIKUCHI2012 Volume 69 Issue 4 Pages 154-159
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSThe Criegee mechanism is now generally thought to correctly describe the major reaction of ozone with diene rubber. However the final product and the mechanism of crack formation by ozone is still not clear. We analyzed the mechanism of cis-1,4-polybutadiene ozonolysis by ab initio molecular orbital calculation and FT-IR spectroscopy. Our study revealed that the final product is hydroxyl ester when the polymer chain is not extended. However, the C=C double bond is broken by ozone when the polymer chain is extended. This leads to decreasing molecular weight and surface cracks.View full abstractDownload PDF (1942K) -
Yasutaka NAGAI, Takeshi SAKURAI, Hitoshi UENO, Koji KOBAYASHI2012 Volume 69 Issue 4 Pages 160-165
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSThe wavelength dependence of the photodegradation of polybutyleneterephthalate-block-polytetrametyleneglycol; (PBT-block-PTMG), has been investigated using monochromatic radiation supplied from the Okazaki Large Spectrograph. From our results, we conclude the following: Main-chain scission occurs when PBT-block-PTMG is exposed to a wavelength of 320 nm or shorter. Moreover, main-chain scission is greatly enhanced for a wavelength of 310 nm. The main photodegradation products are formate, propyl and aldehyde end groups and aliphatic ester groups. The threshold wavelength for the photodegradation of PBT-block-PTMG is ca. 310 nm. The photodegradation of PBT-block-PTMG is induced through hydrogen abstraction by carbonyl groups in n,π* excited states.View full abstractDownload PDF (1858K) -
Hiroyuki MEIJI, Tamotsu HASHIMOTO, Michio URUSHISAKI, Toshikazu SAKAGU ...2012 Volume 69 Issue 4 Pages 166-170
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESS3-Ethyl-3-[(vinyloxy)methyl]-oxetane (EVMO) is a bifunctional monomer with two cationically polymerizable groups, vinyl ether and oxetane. In order to obtain soluble polymers by selective polymerization of one of the two polymerizable groups, the effect of the reaction conditions on the polymerization behavior was investigated. BF3OEt2 as an initiator polymerized the oxetane unit of EVMO selectively to give soluble high-molecular-weight polymers (Mn > 40,000) in CH2Cl2 at −10°C.View full abstractDownload PDF (1216K) -
Do-Hyeon YANG, Wataru FUTAGAMI, Naoki MIZUTANI, Seung-Woo LEE2012 Volume 69 Issue 4 Pages 171-178
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSTiO2/fullerene nanocomposite thin films were fabricated by a surface sol-gel process using C60 (or C70) and Ti(O-nBu)4. Linear film growth was confirmed by quartz crystal microbalance (QCM) and UV-vis absorption spectroscopy. The QCM frequency shift was 26 ± 17 and 27 ± 11 Hz for Ti(O-nBu)4 and C60, respectively, and the adsorption density of C60 was estimated to be 0.5 molecule/nm2. The contact angle alternated according to the type of outermost layers, showing 20–30° and 50–70° for TiO2 and C60, respectively. The surface morphology of the TiO2 and TiO2/C60 nanocomposite thin films was very smooth and uniform over large areas. This result indicates that C60 was uniformly covered by the TiO2 gel surface. Cyclic voltammograms of the fullerene nanocomposite thin films showed two redox peaks: one of C60/C60− at −0.2 V and the other of the amorphous TiOH at 0.15 V. The element ratio of C/Ti inside the TiO2/C60 film was estimated to be 4.7 by XPS measurements, indicating that one C60 molecule is surrounded by a matrix including 13 Ti atoms.View full abstractDownload PDF (2107K)
Note
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Makoto SOYAMA, Yukihiro KIUCHI, Masatoshi IJI2012 Volume 69 Issue 4 Pages 179-183
Published: April 25, 2012
Released on J-STAGE: April 25, 2012
JOURNAL FREE ACCESSTo expand the use of polylactic acid (PLA), a biomass-based polymer, in durable products, we improved its toughness by adding reactive silicones with amino or epoxy functional groups. We investigated the effects of the silicones with regard to their functional group densities and viscosities on their dispersion in PLA, their migration on PLA/silicone composite surfaces, and the toughness of PLA. As a result, reactive silicones that are moderately disperse (particle sizes: 1–20 µm), did not migrate and improved the impact strength of PLA. Moreover, silicones with relatively low viscosity (15–300 mm2/s) improved the break elongation of PLA. Especially, an amino silicone with an amino group equivalent weight of 4000 g/mol and a viscosity of 230 mm2/s remarkably improved the toughness of PLA while maintaining its high flexural strength.View full abstractDownload PDF (803K)
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