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Volume 57, Issue 11
Displaying 1-9 of 9 articles from this issue
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Koji OTA, Mototaka SONE, Hideo MITSUI, Kyo TAKAOKA2000 Volume 57 Issue 11 Pages 701-707
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe state of dissolved water in polydimethylsiloxane (PDMSi) was studied by FT-IR spectroscopy at 20°C, and the thermal dependence of dissolved water in PDMSi was examined. The state was compared with some low molecular weight siloxane and ether compounds. The effect of water clusters in PDMSi on conduction phenomena was also studied. In PDMSi, the water clusters mainly consisted of small clusters such as a monomer-like dimer (hydrated water molecule with oxygen atom in siloxane polymer). The number of large clusters that formed around ether group in PDMSi was very small in contrast to those in other siloxane and ether compounds. The small water cluster existed stably in PDMSi against heating until 180°C better than any other clusters. Dissolved water did not enhance conductivity until 180ppm. But when the amount of dissolved water exceeded 180ppm, the conductivity remarkably increased. It was found that monomer like dimer mainly contributed to the increase in the conductivity.View full abstractDownload PDF (1322K) -
Toshio OGAWA, Tomoyuki SATOU, Satoshi OSAWA2000 Volume 57 Issue 11 Pages 708-714
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSSurface treatments such as plasma and corona discharge treatments were applied to the surface of low density polyethylene sheet and poly ethylene terephthalates film in order to improve adhesive properties. A laminated film was prepared from low density polyethylene sheet and poly ethylene terephthalate film, and the peel strength of the film was determined. The peel strength reached a very high value when the sheet and the film were treated under the appropriate conditions. This strength was higher than that of the laminated films which were prepared using adhesives. Further, the fracture was cohesive failure within the low density polyethylene film.View full abstractDownload PDF (1197K) -
Takashi IIZAWA, Shun MIYAMOTO, Satomi SUGANO2000 Volume 57 Issue 11 Pages 715-721
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIn order to synthesize a core-shell type gel (gel capsule) consisting of a hydrophobic shell layer and a hydrophilic core part, the reaction of a cylindrical 1, 8-diazabicyclo- [5, 4, 0] -7-undecene salt (DAA) of poly (acrylic acid) with alkyl bromide was investigated. Also, the reaction was carried out in the presence of dibromoalkane as a secondary-crosslinker. The reaction was not affected much by the kind of alkyl bromide or dibromoalkane used. When the obtained gel capsule was dipped in water at 50°C, the capsule experienced swelling, and finally burst. The burst time was influenced markedly by thickness of core and shell parts, combination between alkyl bromide and dibromoalkane, and content of dibromoalkane. These results suggest that the burst time was controlled by these factors. When a gel capsule containing dye in the core part was dipped in water, no chemical release was observed until the capsule burst. After the burst, rapid chemical release occurred.View full abstractDownload PDF (3745K) -
Shinya KIMURA, Koji MINAMITANI, Takehiko GOTOH, Shuji SAKOHARA2000 Volume 57 Issue 11 Pages 722-729
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSStearyl acrylate (SA) porous gel with hydrophobic long side chains swells or shrinks rapidly in orgainc solvents in resnonse In ternperature changes. Such a swelling/shrinking of gel is caused by the order-disorder transition of SA side chains. The porous structure of SA gel which is prepared by utilizing the phase separation can be controlled with the cross-linker concentration in preparing the gel. However, a low cross-linker concentration forms a non-porous gel which decreases the response rate. In order to solve these problems, the control of porous structure by copolymerizing methacrylic ester with SA was examined experimentally. The thermoresponsive properties of these copolymer gels were also examined in 1-octanol. Four kinds of methacrylic esters with different lengths of side chain, i. e., methyl-, ethyl-, hexyl- and dodecyl-metacrylate, were used. Even if the concentration of cross-linker was quite low, the porous gels were obtained by copolymerizing these methacrylic esters at an adequate mole ratio; in the case that the mole ratio was less than 0.25, the porous structure was almost independent of the length of side chain of the methacrylic ester. However, the crystalline structure of SA side chains in these gels largely depends on the length of the side chain of the methacrylic ester, and such a change of crystalline structure strongly affects the thermoresponsive properties.View full abstractDownload PDF (5374K) -
Takao KIMURA, Shinichi HIKICHI2000 Volume 57 Issue 11 Pages 730-733
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA series of pH and temperature-responsive (N-isopropylacrylamide-co-itaconic acid) random copolymers were synthesized by radical copolymerization. Their lower critical solution temperatures (LCST) were compared with those of a series of (Nisopropylacrylamide-co-acrylic acid) random copolymers over a acidic range of pH values. LCSTs of the itaconic acid-copolymers were observed at higher temperatures with an increase in the incorporation ratio of itaconic acid units. The LCST behavior was significantly dependent on the variation in pH of the aqueous environment; the LCSTs of itaconic acid-copolymer solutions increased with an increase in the pH values.View full abstractDownload PDF (759K) -
Akinori NISHIO, Amane MOCHIZUKI, Jun-ichi SUGIYAMA, Kazuhiko TAKEUCHI, ...2000 Volume 57 Issue 11 Pages 734-742
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSOrdered polyurethanes with totally head-to-head (H-H) or totally tail-to-tail (T-T) structure were prepared by polyaddition reaction of a nonsymmetnc monomer, p-isocyanatobenzyl isocvanate (PIBI) with a symmetric monomer, ethylene glycol (EG) and 1, 3-benzenedimethanol (BM). The polymerization was conducted under various conditions by changing the order in which the monomers were introduced. The microstructure of the obtained polymer was investigated by 13C NMR spectroscopy, the polymer had the expected structural regularity. The constitutional regularity of the polymers influenced the solubility, thermal properties, crystallinity and optical properties.View full abstractDownload PDF (1538K) -
Nozomu TAKANO, Tomio FUKUDA, Katsumichi ONO2000 Volume 57 Issue 11 Pages 743-750
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe influence of treatment conditions on the structure of siloxane oligomers was studied by using alkoxysilane compounds. The siloxane structure was analyzed by diffuse reflectance spectroscopy of FT-IR. KBr was treated directly with a solution of alkoxysilane, and was used as a sample. As a result of evaluating the relationship between the treatment conditions and the formation ratio of linear siloxane, when the concentration of the alkoxysilane was low, the siloxane becomes difficult to form, but the formation ratio of linear siloxane components was enhanced. This tendency was more remarkable in alkoxysilane compounds of the dimethoxy series than in those of the trimethoxy series. The formation ratio of linear siloxane was lower in alkoxysilane compounds having ethoxy groups than in those having methoxy groups. On the other hand, the formation ratio of linear siloxane was increased with decreasing boiling point of the solvent used for treatment. This tendency was more remarkable in alcohols than in ketones.View full abstractDownload PDF (1455K) -
Yuko SHIBATA, Hiroshi INOUE, Takehiko SHIMOMURA, Hiroshi KUSANAGI2000 Volume 57 Issue 11 Pages 751-756
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIn ESCA of Nylon 6 films, a shoulder peak was found beside the O1s spectra of the amide functional group at higher binding energy. This shoulder peak did not derive from oxgen of amide functional group but appeared when Nylon 6 absorbed water. It suggests that water is adsorbed on the surface of Nylon 6 by hydrogen bonding. Such adsorbed water increased as the crystallinity of Nylon 6 decreased. Because Nylon 6 has enough free amide functional groups in its surface amorphous region, one water molecule could form hydrogen bondings with several amide functional groups. As a result, water molecules are strongly adsorbed on the surface of Nylon 6. Amide functional groups inside also migrated to surface by water absorbed on the surface of Nylon 6.View full abstractDownload PDF (1013K) -
Hiromasa ADACHI, Teruo HASEGAWA2000 Volume 57 Issue 11 Pages 757-759
Published: November 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe dynamic storage modulus for some expanded polystyrene foams was investigated by the dynamic viscoelastic measurements in compression mode. This dynamic storage modulus showed positive correlation with the static modulus, and each value was larger. The dynamic storage modulus after destruction of the cells was less than the modulus before destruction of the cells. The pressure inside the cells and the buckling of column have effects on the resistance against the deformation of the skeleton.View full abstractDownload PDF (528K)
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