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Predecessor
Volume 57, Issue 3
Displaying 1-7 of 7 articles from this issue
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Yasushi HATANO, Keiji NAGAYA, Sadao HIBI, Tsuneo KAWAKAMI, Yuuji SAKAM ...2000 Volume 57 Issue 3 Pages 105-110
Published: March 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe have introduced a simulation model for the orientation distribution of crystallites for strip-biaxial stretching, by assuming suitable aggregations of polycrystallites in syndiotactic polypropylene films. In this report, we adopted five kinds of slip systems in the crystal unit of syndiotactic polypropylene crystallites. The azimuthal rotations of crystal units always selected individual slip systems for plastic deformation, applying the principle of maximum plastic work.View full abstractDownload PDF (1058K) -
Yasushi HATANO, Keiji NAGAYA, Sadao HIBI, Tsuneo KAWAKAMI, Yuuji SAKAM ...2000 Volume 57 Issue 3 Pages 111-119
Published: March 25, 2000
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSWe have estimated the orientation distribution function of each plane for strip-biaxial stretching in syndiotactic polypropylene films. The pole figure device familiar in X-ray diffraction was used. These distribution functions were compared with that of a simulation of orientation in crystallites after strip-biaxial stretching, by assuming polycrystalline aggregations. We have evaluated the Rfactor calculated from observed and simulated distribution function of streched specimens. We analyzed the mechanism of orientation for the strip-biaxial stretching process in which the {110}, <001> and (100), <001> slip systems dominated in five types of slip systems by applying the principle of maximum plastic work.View full abstractDownload PDF (1556K) -
Osamu HARADA, Kazushige KADOTA, Tohei YAMAMOTO2000 Volume 57 Issue 3 Pages 120-125
Published: March 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe vinyl group was introduced into collagen polypeptide (PEP) with 2-methacryloyloxyethyl isocyanate (MOI) to give methacryloyl polypeptide (PEP-MOI). Radical polymerization of PEP-MOI and copolymerization with methyl methacrylate (MMA) were carried out by using 4, 4′-azobis (4-cyanovaleric acid) as an initiator. Poly (PEP-MOI) and copolymers were obtained. Initiator free graft polymerization of PEP-MOI onto poly (styrene) film was carried out and poly (PEP-MOI) -graft-poly (styrene), which has a hydrophilic surface, was obtained.View full abstractDownload PDF (1007K) -
Mitsuhiro SUGIMOTO, Teruya MATSUMOTO, Teizo ISONO, Tohei YAMAMOTO, Mik ...2000 Volume 57 Issue 3 Pages 126-131
Published: March 25, 2000
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSRadical copolymerizations of vinyl acetate (VAc) with vinyl butylate (VBu), vinyl isobutylate (ViBu), vinyl trifluoroacetate (VTFAc), and vinyl benzoate (VBz), and those of vinyl pivalate (VP) with VTFAc were carried out at 0°C by UV irradiation. The cotacticities were determined from the 1HNMR spectra of poly (vinyl alcohol) s (PVAs) obtained by saponification of the copolymers, they varied with the monomer combination and feed monomer composition. The cotacticities of VAc/VBu and VAc/VTFAc copolymers could be expressed by coisotactic parameters derived on the basis of the terminal model, but those of VAc/ViBu copolymer could not be expressed by the terminal model and could be expressed well by the penultimate model. In the cases of VAc/VBz and VP/VTFAc copolymers, both of the terminal and penultimate model were not enough to explain the cotacticities indicating a new model.View full abstractDownload PDF (786K) -
Tetsuji HIRANO, Ryotaro AMANO, Kenjiro ONIMURA, Hiromori TSUTSUMI, Tsu ...2000 Volume 57 Issue 3 Pages 132-141
Published: March 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effects of reaction conditions, types and molecular weights of polyamide 6 (PA6) radical initiators (PA6ini) and a chain transfer agent on the structure of block copolymers were studied. For the polymerizations of methyl methacrylate (MMA) with PA6ini, the poly (MMA) contents, the molecular weights of poly (MMA) segments of the block copolymer and the initiator efficiency decreased with an increase of the ratio of azo group concentration to MMA concentration. Poly (MMA) segment molecular weight decreased with a decrease of the molecular weight of PA6ini, while the poly (MMA) content and the initiator efficiency increased. The initiator efficiency of azo group in the center of PA6ini molecular chain was lower than that of azo group at the terminal of PA6ini. Solvents, reaction times and reaction temperatures affected the structure of PA6-block-poly (MMA). The molecular weight of poly (MMA) segment was controlled by addition of a chain transfer agent. Molecular weights of poly (styrene) (St) segment of PA6-block-poly (St) obtained by heterogeneous polymerization were higher than those of block copolymers obtained from homogeneous polymerization. Thermal properties of block copolymers were measured by differential scanning calorimeter (DSC).View full abstractDownload PDF (1635K) -
Yuan LIU, Sadao HIBI, Tsuneo KAWAKAMI, Minoru BESSHO, Masahiro MORITA, ...2000 Volume 57 Issue 3 Pages 142-151
Published: March 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNon-stretched poly (ethylene terephthalate) (PET) films and strip-biaxially stretched PET films were annealed and treated with boiling water, and we have used tensile testing to investigate the behavior of stress-strain curve with variation of crystallinity. As PET sheets were stretched at 80°C, the stress-strain curve of non-stretched PET films was explored at room temperature and 80°C. The offaxis angle stretching of strip-biaxially stretched PET films was done at room temperature, and the stress-strain curve was explored at room temperature. The results were analyzed on the basis of the series model of crystalline and amorphous phases of non-stretched and strip-biaxially stretched PET films to give the ratios of Young's modulus and yield stress of crystalline and amorphous phases.View full abstractDownload PDF (1664K) -
Mitsuhiro SUGIMOTO, Atsushi FUKUDA, Takashi KOJIMA, Tohei YAMAMOTO, Mi ...2000 Volume 57 Issue 3 Pages 152-157
Published: March 25, 2000
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSRadical polymerization of various vinyl esters was carried out at several temperatures to estimate the substituent effect and the temperature effect on the tacticities. In the case of thermal polymerization, the isotacticity increased, and the syndiotacticity decreased with increasing bulkiness of substituent and rising temperature. But in the case of vinyl benzoate (VBz), isotacticitiy decreased and syndiotacticity increased with rising temperature, suggesting an-stacking effect. By photo-irradiation, the tacticity changed from that of thermal polymerizations, and when polymerization was carried out under light passed through an IR filter, the differences disappeared. Hence, we considered that the difference between thermal polymerization and photo polymerization was caused by IR rays.View full abstractDownload PDF (853K)
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