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Volume 38, Issue 8
Displaying 1-9 of 9 articles from this issue
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Atsushi MURAKAMI, Haruo KANATANI, Tadatsugu YOSIKI1981 Volume 38 Issue 8 Pages 507-513
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSImpact tensile properties of the blends of ethylene ionomers (sodium and zinc salts) and rubbers (acrylonitrile butadiene rubber (n-NBR) and carboxylic acrylonitrile butadiene rubber (a-NBR)) have been studied by the dynamic mechanical measurements, the impact tensile tests and the electron microscopic observations.
The fracture energy of all n-NBR blends shows maximum at about 10 weight % rubber content. The energy of the blend with the zinc salt ionomer shows a remarkable reduction at 30% rubber content.
The toughening effect of blending a-NBR is moderate. The fracture energy of all a-NBR blends shows a modest maximum at about 20% rubber content. The energy of the blend with the zinc salt ionomer endures the highest level at 30% rubber content.
Such differences in the impact tensile properties of the n-NBR and the a-NBR blends can be attributed to the differences in the interactions of the two polymer phases, e. g., the interfacial ionic bond, as well as in the morphological structures of the rubber phases.View full abstractDownload PDF (5918K) -
Yoshiyuki IKEDA, Kunihiro UENO, Hajime YOSHIDA, Yasuaki KOZAI1981 Volume 38 Issue 8 Pages 515-522
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe polymerization of acryloyl amino adds (glycine, β-alanine, γ-amino-n-butyric acid and ∈-amino-ncaproic acid) by use of ammonium persulfate or azobisisobutyronitrile as an initiator were carried out in aqueous solutions, and the pH dependence of the rate of polymerization (Rp) was investigated. Rp had a maximum value for each monomer in acidic solutions, and decreased as the pH increased up to 5-6. The pH dependences in the region of pH large than 6 varied depending on the combination of monomers and initiators. In case of ammonium persulfate as the initiator, Rp was proportional to the monomer concentration in acidic solutions, while it was proportional to 1.5th power of the concentration in neutral or alkaline solutions. In case of azobisisobutyronitrile, Rp was proportional to the monomer concentration throughout the whole pH region investigated. Rp was proportional to the square root of the initiator concentration. On the basis of these results, the characteristics of the polymerization reactions were discussed.View full abstractDownload PDF (1131K) -
Yoshio IMAI, Yuzo SATO, Mitsuru UEDA1981 Volume 38 Issue 8 Pages 523-527
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSReactions of p-bis (2-nitrovinyl) benzene (I) and p-bis- (2, 2-dicyanovinyl) benzene (IIa) with thiols afforded the corresponding adducts in high yields. Polyadditions of dithiols to I, IIa, and m-bis (2, 2-dicyanovinyl) benzene (IIb) in various solvents at 15-60°C produced polysulfides with the inberent viscosities up to 0.2dl/g. All the polymers obtained were highly soluble in a variety of organic solvents including dimethylformamide, tetrahydrofuran, aBd m-cresol. They began to decompose at temperatures ranging from 120 to 200°C.View full abstractDownload PDF (701K) -
Hozumi TANAKA, Chiaki AZUMA, Kohei SANUI, Naoya OGATA1981 Volume 38 Issue 8 Pages 529-533
Published: August 25, 1981
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSPhotosensitive polymers were prepared by esterification of poly (vinyl alcohol) (PVA) with chloroacetic acids to obtain mono-, di-, or tri-chloroacetylated PVA of different esterification degrees (20-50mol%). Irradiation of these polymers with ultraviolet light caused a crosslinking reaction owing to a radical degradation reaction of chloroacetyl groups within a minute and the apparent order of phtosensitivity of these polymers was as follows: tri-<di-<mono-chloroacetylated PVA. Chloroacetylated PVA had a higher sensitivity to the irradiation than chloroacetylated chitosan because of soft segments of PVA. A model reaction for the photo-crosslinking reaction was carried out to establish the reaction mechanism.View full abstractDownload PDF (706K) -
Yasushi WATANABE, Tadashi SHIROTA, Yoshinao ISHIKURE1981 Volume 38 Issue 8 Pages 535-540
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe progress of degradation has been studied for polyethylene sheet (3mm thick) irradiated by a “sunshinetype” carbon-arc weathering tester, without spraying water. Layers of constant thickness (0.05 or 0.1mm) were scraped, by means of a side-milling cutter mounted on a notching machine. Powdered sample from each layer collected was subjected to various testings, infrared spectroscopy (IR), differential scanning calorimetry (DSC) and density measurement. The formation of carbonyl group was distinguished in the surface region and the rate was much faster than that in the inner regions, suggesting different mechanisms for the formation. The density increased and the melting temperature decreased by the exposure and the change was remarkable in surface layers. Vicker's hardness number measured on each layer surface increased in accordance with the formation of carbonyl group.View full abstractDownload PDF (2327K) -
Shizunobu HASHIMOTO, Takayuki YAMASHITA, Junichi HINO1981 Volume 38 Issue 8 Pages 541-545
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe betaines, 2- (N-benzylazetidino) propionate (BEA-PL) and 3- (N-benzylazetidino) propylsulfonate (BEA-PS), were prepared in good yields by addition reactions of 1-benzylazetidine and cyclic esters such as β-propiolactone and 3-hydroxy-1-propane sulfonic acid sultone. The analyses of the structures of the obtained compounds were made by the NMR and IR spectroscopy and the elemental analyses. The bulk polymerization of betaines proceeded spontaneously by heating to the melting point. The polymer from (BEA-PL) was a white greasy substance of the moleculer weight of about 6000, and the main chain was made of the alternate sequence of the tertiary amino group and ester group. The polymerization of (BEA-PS) produced the ionene polymer which had the propylsulfonate anions as pendant groups. The polymerization mechanisms were discussed in terms of the difference in the reactivities between the carboxylate anion of (BEA-PL) and the sulfonate anion of (BEA-PS).View full abstractDownload PDF (677K) -
Toshihiro KASHIMA, Kuniomi ETOH1981 Volume 38 Issue 8 Pages 547-553
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSRelationship between the molecular weight and the crystallinity of terephthalate copolyesters has been investigated by differential scanning calorimetry (DSC).
Crystallinity was measured for poly (ethylene terephthalate) or poly (buthylene terephthalate) copolyesters containing adipic acid, sebacic acid, decane-dicarboxylic acid, isophthalic acid, poly (tetramethylene glycol). Maximum degree and rate of crystallization were found for the copolyesters having a reduced viscosity (ηsp/C), 0.3. It was observed that the crystallinity of copolyesters was concerned with their molecular structures: with increasing number (m) of methylene groups per p-phenylene group in a copolymer chain, the degree of crystallizatin decreased and the rate of crystallization became maximum at an m value, ca. 6.View full abstractDownload PDF (1076K) -
Shigeru HATTORI, Hisae NAKAHARA, Toshio KAMATA1981 Volume 38 Issue 8 Pages 555-557
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAccording to our previous results, poly (methyl methacrylate) (PMMA) was not eluted by n-butyl chloride (NBC) from GPC columns packed with polystyrene gel at 35°C owing to the adsorption of PMMA on the gel particles. The present study reports the GPG measurements with tetrahydrofuran-NBC mixed solvents at 35°C. The threshold NBC content at which PMMA became unelutable from the GPC columns depended on the molecular weight of PMMA.View full abstractDownload PDF (447K) -
Hiroko KYOTANI, Kanji SASAKI, Hisaaki KANETSUNA1981 Volume 38 Issue 8 Pages 559-561
Published: August 25, 1981
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPoly (β-benzyl L-aspartate) film in which the polymer assumes right handed α-helical form was prepared by casting slowly the chloroform solution under a moist atmosphere. Dielectric dispersion and thermally stimulated current (TSC) without poling were measured. A peak was observed in the dielectric dispersion measured at 29-105°C, the latter of which is near the transition region temperature from the right handed α-to left handed ω-helical form. TSC was observed at temperatures below 100°C and also in a higher temperature region where the transition takes place. It is inferred that the movements of the side chain dipoles, and those of the main chain dipoles in addition in the transition temperature region, engender the observed TSC.View full abstractDownload PDF (433K)
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