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Predecessor
Volume 67, Issue 4
Displaying 1-7 of 7 articles from this issue
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Kazuhiko YAGUCHI, Masaaki MUROYA1994 Volume 67 Issue 4 Pages 217-222
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSIn order to find the effect of boron impregnation on the formation of three dimensional network in the silica structure, silica sol containing boron was synthesized by hydrolysis of tetraethyl ortho silicate, and the viscosity of the sol was measured as a function of the passage of time. The viscosity of the sol containing boron was enhanced in a shorter time than that of the boron-free sol. It was indicated that the rate of polycondensation in the sol was accelerated by the presence of proton and borate ions which were formed boric acid [B (OH) 3].
Thin silica films were prepared on metal substrates from the differently aged sols, and FT-IRAS of those films was measured. An absorption band at 1400 cm-1, which is assigned to asymmetric B-O-B stretching vibration of trigonal boron, was observed in the boron-containing silica films. The intensity of the band was proportional to the boron concentration. On the other hand, an absoption band at 1065 cm-1, which was related to the formation of skeletal structure of silica, was not affected at all by the presence of boron. It was suggested that boron in the polycondensed silica formed some borates, such as diborate, tetraborate, and boroxol, which would stay independent of the silica skeletal structure.
A boiling treatment of the films in hydrochloric acid (pH 2) or water promoted pores in such films.View full abstractDownload PDF (737K) -
Viscoelasticities of Alkyd Resin Varnish and Characteristics of the Alkyd ResinsToshihide FUJITANI, Jun AKUI, Masahide KAWARAYA1994 Volume 67 Issue 4 Pages 223-230
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe relation between the rheology of resin solutions (varnishes) and the characteristics of resins was investigated. In this study, the dynamic viscoelasticities of their varnish were measured by oscillation method, and the relation to the properties of the resins, such as molecular weights (Mw), molecular weight distributions (Mw/Mn), high molecular weight part fractions and solubility were evaluated.
And the following results were obtained.
1) The molecular weight distribution of the resins shifted depending on the components, i. e. oil length and kinds of oil, dibasic acid and alcohol.
2) The dynamic viscoelastic properties of the resin solution varied with used resin and solvent.
3) The dynamic storage modulus G' of the solutions at a fixed viscosity was dependent on the molecular weight distributions, especially the fraction of the high molecular weight molecules in the resin. The higher the average molecular weight was, and the higher the fraction of high nolecular weight molecule was, the greater the dynamic modulus (G') of solutions became.View full abstractDownload PDF (774K) -
Norio TSUBOKAWA, Takuya KIMOTO, Sachio YOSHIKAWA1994 Volume 67 Issue 4 Pages 231-238
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSFunctionalized silica gels having alcoholic hydroxyl, mercaptopropyl, aminopropyl, chloropropyl, and methacryloxypropyl groups were successfully prepared by the copolycondensation (sol-gel process) of tetraethoxysilane with alkoxysilane (silane coupling agent). The effects of functional groups on the silica gel surface on the polymerization of vinyl monomers initiated by benzoyl peroxide or 2, 2'-azobisisobutyronitrile were investigated. The radical polymerization of vinyl monomers was considerably retarded in the presence of these functionalized silica gels and the corresponding polymers were effectively grafted onto these surfaces. The rate of polymerization, however, was not affected by the presence of unmodified silica gel and no grafting of polymers onto the surface was observed. These results indicate that the chain transfer reaction of growing polymer radical to functional groups on silica gel surface forms radicals on the surface, which then couples with growing polymer radical and/or reinitiates the polymerization to give rise to the grafting of polymers onto the surface. In the case of silica gel having methacryloxypropyl groups, the grafting based on the copolymerization of vinyl monomer with the surface methacryloxypropyl groups was considered to proceed. Polymer-grafted silica gel was found to produce a stable dispersion in good solvents for grafted chain.View full abstractDownload PDF (805K) -
Electro-poly merization MethodIsao SEKINE, Makoto YUASA1994 Volume 67 Issue 4 Pages 239-249
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
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Synthesis and Polymerization of Monomers that Undergo No Shrinkage FunctionFumio SANDA, Takeshi ENDO1994 Volume 67 Issue 4 Pages 250-257
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (946K) -
Classification of Japanese “Kabuki” art by using multivariate methodsEitaro MASUYAMA, [in Japanese], [in Japanese]1994 Volume 67 Issue 4 Pages 258-262
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
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Masahiko ABE1994 Volume 67 Issue 4 Pages 263-272
Published: April 20, 1994
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (1289K)
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