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Volume 37, Issue 12
Displaying 1-9 of 9 articles from this issue
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Takashi KAMON, Katsuyoshi SAITO1980 Volume 37 Issue 12 Pages 765-771
Published: December 25, 1980
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSAliphatic dihydrazide dispersed epoxy resins has a pot life longer than four months at room temperature and cures smoothly when heated above 150°C. The curing mechanism of these resins was found to be the reaction of epoxy group with active hydrogen atoms on the terminal nitrogen of hydrazide, as like epoxy resins curing with diamines. The study of dynamic mechanical properties of the cured epoxy resins revealed that the glass-transition temperature (Tg), and the cross-linking density (ρ (E′) ) increase with decreasing number of CH2 group between two terminal hydrazide groups. Dihydrazide cured resins have higher Tg than diamine cured resins with the same ρ (E′) , these results suggest that highly polar hydrazide groups in the resins interact more strongly than amine groups in the glassy state.View full abstractDownload PDF (1139K) -
Isao IKEDA, Kimihiro SUZUKI1980 Volume 37 Issue 12 Pages 773-779
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTransition polymerization of acrylamide (AAm) initiated by sodiummetallated poly (vinyl alcohol) (PVA) was investigated. PVA dissolved in an aprotic polar solvent such as dimethyl sulfoxide (DMSO) or hexamethylphosphoramide (HMPA) was metallated with dimsyl sodium, sodium naphthalene or sodium methoxide followed by addition of AAm solution. The products consisting of PVA and transition polymer which contains poly (β-alanine) component and poly (acrylamide) one were obtained. When the products were extracted with methanol and hot water, the methanol-insoluble and watersoluble fractions were confirmed to contain the graft copolymers by the turbidimetry and the acetylation. Transition polymer content and transition ratio of the fractions increased with increase in the reaction temperature and the degree of sodium metallation and were hardly affected by the kind of metallation reagents. Results of the acetylation, however, suggested that the graft copolymers were effectively prepared with decreasing degree of sodium metallation of PVA.View full abstractDownload PDF (1096K) -
Toshiaki TAKAMATSU, Jinichi WADA, Eiichi FUKADA, Hiroshi MATSUMOTO1980 Volume 37 Issue 12 Pages 781-787
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSVarious graft copolymers of expanded poly (tetrafluoroethylene) (EPTFE) were prepared by γ-irradiation technique and were examined for biocompatibility. EPTFE used were tubes of 10 mm in internal diameter with a thickness of 1 mm and sheets with a thickness of 0.79 mm. Monomers used were vinyl acetate (VAc), methyl methacrylate (MMA), styrene (St), and 2-hydroxyethyl methacrylate (HEMA). EPTFE was irradiated by γ-ray in these monomer liquids and graft copolymers were made. EPTFE-vinyl alcohol (VAl) graft was prepared by alcoholysis of EPTFE-VAc graft and EPTFE-sulforated styrene graft was prepared by sulfonation of ERTFE-St graft. Adsorption of saline solution on these graft copolymer tubes were determined for the specimens shaken repeatedly in the solution at room temperature. The saturated value of adsorption increased with the increase of degree of grafting and of hydrophilicity of the polymers. The contact angle of saline solution on these graft copolymers gradually decreased with the increase of the degree of grafting. The patency of these grafted tubes in vivo test showed good results when the degree of grafting was below 5% and reduced in the order of VAl>MMA>VAc>St>Sulfonated St grafts. Implantation of EPTFE-sulfonated St graft tubes to the superior vene cava of dog caused hemolysis and thick intima by thrombus was produced on the wall.View full abstractDownload PDF (1468K) -
Kenji OKUNO1980 Volume 37 Issue 12 Pages 789-796
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFlexural modulus of composites with plane-oriented planar reinforcement has been investigated as a function of flake aspect ratio. The flexural moduli of injection-molded mica or glass-flake filled polypropylene (PP) and styrene-acrylonitrile copolymer (AS) were measured with an Instron tensile testing instrument at 20, 50, 80, and 110°C. The experimental results indicate a strong dependences of the flexural moduli on the flake aspect ratios. The results were compared with the theoretical treatments of Padawer and Beecher, Tsai and Halpin, and Riley. Riley's analysis is based on the virtual work analysis and takes filler-filler interactions into account. This treatment, originally developed for short-fiber composites, was modified for composites with rectangular-shaped flakes. The calculated flexural modulus values according to the modified Riley's equations were close to the observed ones.View full abstractDownload PDF (2031K) -
Mitsuyoshi FUJIYAMA, Yoshimi KOYA, Keiichi AZUMA1980 Volume 37 Issue 12 Pages 797-801
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe structure and properties of isotactic polypropylene (i-PP) cross-linked with the aids of 1, 2-polybutadiene and peroxide in molten state have been investigated by viscoelastic and thermal measurements. The cross-linked i-PP shows a similar value of elastic modulus to that of uncross-linked i-PP, and still keeps the high rigidity and high heat distortion temperature which are characteristic of i-PP. The αa absorption temperature of the cross-linked i-PP is 10-20°C higher than that of uncrosslinked i-PP, suggesting that the thermal motion of amorphous chains in cross-linked i-PP is restrained. The melting point of the cross-linked i-PP becomes about 10°C lower as compared with that of uncrosslinked i-PP but the decrease of enthalpy of fusion is very little. This means that the cross-linking results in the decrease of crystallinity while the degree of the crystallinity is kept unchanged. The crystallization temperature of the cross-linked i-PP is 10-15°C higher than that of uncross-linked i-PP, suggesting that a residual structure of crystallites is still retained in the molten state of the crosslinked i-PP.View full abstractDownload PDF (751K) -
Masato KODAKA1980 Volume 37 Issue 12 Pages 803-807
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIt is expected that an enzyme-reaction toward a substrate can be inhibited by the formation of an inclusion complex with α-cyclodextrin (α-CD). Ultraviolet spectra showed that p-nitrophenyl-β-D-glucopyranoside (PNPG) forms a complex with α-CD whereas o-nitrophenyl-β-D-glucopyranoside (ONPG) hardly forms such a complex. The hydrolysis of PNPG by β-glucosidase is inhibited by α-CD. The hydrolysis of p-nitrophenyl phosphate (PNPP) by alkaline phosphatase is also inhibited. For the last two reactions, a scheme is assumed to analyze the experimental results.View full abstractDownload PDF (1091K) -
Nobuyoshi ITO, Hiroshi YOSHIDA1980 Volume 37 Issue 12 Pages 809-814
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAcetoxymethyl vinyl ketone (AMVK), prepared through the Reppe reaction of 1, 4-dihydroxy-2-butyne, was homopolymerized and copolymerized with methyl methacrylate (MMA) or styrene (St) by azobisisobutyronitrile. The monomer reactivity ratio was evaluated as γ1=0.95 and γ2=0.77 in copolymerization of MMA (M1) -AMVK (M2), and as γ1=0.10 and γ2=0.36 in copolymerization of St (M1) -AMVK (M2). As calculated from the monomer reactivity ratio of AMVK-St, Q=2.3 and e=1.0. AMVK and MMA copolymerize randomly, while AMVK and St slightly more alternately. The poly (acethoxymethyl vinyl ketone) (PAMVK) was a semielastic mass having the glass-transition temperature (Tg) of 36-41°C, which is close to the softening temperature of poly (methyl vinyl ketone) (PMVK) (40-60°C). The quantum yields of chain scission (φcs) of photolysis at 285 or 312nm in solution, determined by gel-permeation chromatography, were (1.6-3.3) ×10-2, (2.3-2.7) ×10-2, and (3.4-5.7) ×10-2, respectively, for PAMVK, poly (acetoxymethyl vinyl ketone-methyl methacrylate), and poly (acetoxymethyl vinyl ketone-styrene), which were of the same order with that for PMVK (2×10-2).View full abstractDownload PDF (856K) -
Shigeru HAYAMA, Shogo NIINO, Makoto TAKEISHI1980 Volume 37 Issue 12 Pages 815-817
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSoluble poly (naphthylene-1, 5-diyl), poly (anthraquinone-1, 4-diyl), poly (4, 4′-biphenylenevinylene), and related copolymers were prepared via bisdiazonium chloride purely obtained from 1, 5-diaminonaphthalene, 1, 4-diaminoanthraquinone, and 4, 4′-diaminostilbene, which was an extention of the synthetic procedure of soluble poly (4, 4′-biphenylene). The homopolymers were infusible and decomposed exothermically above 250°C, whereas their copolymers with methylmethacrylate and acrylamide melted at 150-180°C. Viscosity curves of those samples in dimethylformamide revealed anomolous peaks at concentrations 0.2-0.05g/100ml, which was consistent with that observed in the viscosity curve of poly (4, 4′-biphenylene) in dimethylformamide.View full abstractDownload PDF (447K) -
Norihiko MINOURA, Tsutomu NAKAGAWA1980 Volume 37 Issue 12 Pages 819-821
Published: December 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPermeability of poly (γ-methyl L-glutamate) membrane to NaCl, Na2SO4, MgSO4, glucose, and sucrose was studied, and phenomenological coefficients, namely reflection coefficient and mechanical permeability, were estimated. The reflection coefficients of these solutes are very small, of the order of 10-2-10-3.View full abstractDownload PDF (420K)
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