Sen'i Gakkaishi
Online ISSN : 1884-2259
Print ISSN : 0037-9875
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Volume 62, Issue 7
Special Issue on "Novel Fiber Chemistry"
Displaying 1-15 of 15 articles from this issue
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  • Consideration of Solvent Effect on Precipitation Polymerization of Poly(ether-ketone)s via Friedel-Craft Acylation
    Manabu Ohmori, Kunio Kimura, Yuhiko Yamashita, Yoshimitsu Sakaguchi
    2006 Volume 62 Issue 7 Pages 141-149
    Published: 2006
    Released on J-STAGE: August 20, 2006
    DOIhttps://doi.org/10.2115/fiber.62.141
    JOURNAL FREE ACCESS
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    Precipitation polymerization of diphenyl ether and isophthaloyl chloride catalyzed by AlCl3 via Friedel-Crafts acylation was examined in various solvents to clarify the polymerization behavior. Polymerizations were carried out in three categorized solvents based on the solubility to both catalyst and polymer, which were cyclohexane (CH), 1,2-dichloroethane (DCE) and DCE containing 2 wt% nitrobenzene (2%-NB). In DCE which was widely used, the oligomers were precipitated as a form of the complex with AlCl3 at the early stage of polymerization. The precipitates of the oligomers were swollen by the solvent, in which any short-range regular structure did not exist. The further polymerization proceeded even in the precipitates with eliminating by-produced HCl, and high molecular weight poly(ether-ketone)s (PEK) were finally formed. Nevertheless the reaction in 2%-NB yielded the well-swollen precipitates, the high molecular weight PEK was not synthesized in the precipitates because the reaction was terminated by not only the inefficient elimination of HCl due to the higher solubility of HCl but also the deactivation of catalyst by coordination of NB to AlCl3. Although the precipitation occurred more readily in CH due to the lower solubility of oligomers, the polymer was not synthesized in the precipitates. The resulting precipitates comprised of the dimers were not swollen in this case, and thereby it was very difficult to react between dimers and eliminate HCl from the precipitates. The solvents having high miscibility to catalyst and the polymers, low solubility of HCl gas, and no basicity are necessary for making high molecular weight polymers via the precipitation polymerization.
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  • Influence of the Addition of Tertiary Amine on the Sequence Length of Aromatic Polyamide Copolymers in the Solution Polycondensation
    Yoshimitsu Sakaguchi, Atsushi Kaji, Shigeji Konagaya
    2006 Volume 62 Issue 7 Pages 150-154
    Published: 2006
    Released on J-STAGE: August 20, 2006
    DOIhttps://doi.org/10.2115/fiber.62.150
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    Sequence distribution in the aromatic polyamide copolymerization with 4,4’-diaminodiphenyl ether, 4,4’-diaminodiphenylsulfone and isophthaloyl chloride in N-methyl-2-pyrrolidone was changed from random to some block distribution by adding tertiary amine such as pyridine and triethylamine into the reaction system. The reaction mechanism was examined by some model reactions to clarify the initial stage of polymerization and following conclusion was derived: As reactivity of amino groups in 4,4’-diaminodiphenyl ether became faster than the diffusion of diacid chloride into the reaction solution with the existence of tertiary amine, 4,4’-diaminodiphenyl ether ⁄⁄ isophthaloyl chloride block segments were quickly formed at the initial stage of polymerization to give copolymers with some block tendency.
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  • Novel Fluorine-containing Poly(aryl ether amide)s derived from 2,3,4,5,6-Pentafluorobenzoic Acid
    Ken Tanaka, Natsuko Sato, Shinichi Yamazaki, Kunio Kimura, Yuhiko Yama ...
    2006 Volume 62 Issue 7 Pages 155-161
    Published: 2006
    Released on J-STAGE: August 20, 2006
    DOIhttps://doi.org/10.2115/fiber.62.155
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    Various amide-containing aryl fluorides were synthesized from 2,3,4,5,6-pentafluorobenzoic acid, and novel fifteen AA-BB type and three AB type fluorine-containing poly(aryl ether amide)s (F-PEA) were obtained by nucleophilic aromatic substitution reaction. The synthesized aryl fluorides possessed several reactive carbons for the nucleophilic attack and cross-linking reaction occurred at 100°C. Polymerizations were carried out at 80°C to avoid cross-linking and stopped just before gelation occurred. They had all para connected linear structures. The obtained F-PEAs showed excellent solubility and afforded tough transparent films by casting method. They also exhibited high Tg in the range of 179-273°C depending on the molecular structure. They showed good thermal stability, and even though F-PEAs contained amide linkage into the repeating unit of polymer molecule, they exhibited excellent hydrophobicity due to the incorporation of 2,3,5,6-tetrafluoro-1,4-phenylene moiety.
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  • Synthesis of Chitosan Microemulsion
    Rie Kakiuchi, Piao Qiyu, Yoshiharu Kimura, Masuo Nakagawa
    2006 Volume 62 Issue 7 Pages 162-166
    Published: 2006
    Released on J-STAGE: August 20, 2006
    DOIhttps://doi.org/10.2115/fiber.62.162
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    Chitosan is an aminoglucan that has many applications in various fields. For most of the purposes, it is usually dissolved in aqueous solution of acetic acid. However the presence of acid is inadequate in applying the chitosan solutions as cosmetics and food additives for which chitosan should be effectively used. In this study, chitosan is emulsified in an acid-free aqueous medium by the aid of nonionic surfactants and ion exchange resin. The solution properties of the emulsions are studied by DLS and other methods.
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  • Fabrication of Poly(p-oxycinnamoyl) Nano-scale particles
    Yoshito Hirai, Shin-ichiro Kohama, Shinichi Yamazaki, Kunio Kimura
    2006 Volume 62 Issue 7 Pages 167-174
    Published: 2006
    Released on J-STAGE: August 20, 2006
    DOIhttps://doi.org/10.2115/fiber.62.167
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    Fabrication of poly(p-oxycinnamoyl) (POC) nano-scale particles was examined by using self-seeding polymerization of (E)-4-acetoxycinnamic acid in liquid paraffin. The diameter of the POC spheres was very susceptible to the polymerization temperature and the temperature drop was very efficient to control the nucleation process by the adjustment of the degree of super saturation leading to the decrease in the diameter. The average diameter of the spheres prepared at 320°C was 3.6 µm, whereas, the temperature drop from 320°C to 250°C just before the nucleation afforded the POC microspheres having average diameter of 2.2 µm. In order to prepare the nano-scale particles, only the self-seeding polymerization was not sufficient and the control of the growth process was additionally required. The POC particles having 600 nm of the average diameter were obtained by not only the temperature change from 320°C to 250°C and then 320°C but also the addition of 4-octadecyloxybiphenyl as a coalescence inhibitor. The average diameter was in nano-scale, but the diameter distribution became broader with bimodality.
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