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Volume 44, Issue 6
Displaying 1-11 of 11 articles from this issue
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Sadao HIBI, Akihiro YOKOYAMA, Keiko ITOH, Eiji NAKANISHI, Matsuo MAEDA1987 Volume 44 Issue 6 Pages 409-419
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe polarized fluorescent intensity is affected by two factors: the optical properties of the optically biaxial substance, which give rise to extraordinary lights in the sample, and the molecular structures of the optically anisotropic polymer solid dyed with fluorescent dyestuff. The effects of these factors on this intensity are introduced into the formulae used for evaluating the molecular orientation. In these formulae, the fluorescent intensity has been expressed in terms of measurable velues by separating into two terms: one depends on the molecular orientation and the other concerns the nature of the molecular structures and the device of optical measurement. It has thus been possible to pick up the terms associated with the fourth moment of direction cosines of the non-crystalline molecular chain axis. How the electric amplitude difference between the refracted extraordinary lights influences the fluorescent intensity is also considered.View full abstractDownload PDF (2153K) -
Katsuhiko NAKAMAE, Takashi NISHINO, Katsuhiko HATA, Tsunetaka MATSUMOT ...1987 Volume 44 Issue 6 Pages 421-428
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe temperature dependence of the elastic modulus E1 of crystalline regions of Nylon 6α-form in the direction parallel to the chain axis has been investigated by X-ray diffraction. At room temperature, the value of E1 for the (0140) plane of Nylon 6α-form was 157 GPa. But the E1 value decreased with increasing temperature, and it became 40 GPa at 175s°C. Particularly above 125°C, both the decrement of the E1 value and the diffraction intensity for the (0140) plane were larger. The disorder of crystalline regions also increases above 125°C. These phenomena are considered to be due to the increment of the incoherent lattice vibrations. The lattice spacing for the (0140) plane decreased with increasing temperature (thermal expansion coefficient is-3.93×10-5K-1 below 125°C, and-10.3×10-5K-1 above 125°C). This means that the molecular contraction, which is an indirect effect of the incoherent thermal vibration, occurs at high temperature. The continuous decrement of the E1 value with increasing temperature can be explained by the contraction of a Nylon 6 chain caused by the internal rotation at the amide group in the crystalline regions.View full abstractDownload PDF (2308K) -
Kazuko HAYASHI, Hiroshi FUKUMURA, Noboru YAMAMOTO, Iwao YAMASHITA1987 Volume 44 Issue 6 Pages 429-436
Published: June 25, 1987
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSIn order to prepare an antithrombogenic material by making polymer surfaces hydrophilic, acrylamide (AAm) was radiation-graft copolymerized onto poly (tetrafluoroethylene) (PTFE) tubes by preirradiation in Arand the following treatment with a monomer aqueous solution. The grafting percentage determined from the weight increment was so small (below 0.3%) that the surface grafting percentage was calculated by ESCA for the grafted tubes. The in vivo antithrombogenicity was evaluated by relative patent time in the implantation into canine peripheral veins and its relation to the contact angle of water or surface grafting percentage was discussed. From the results of ESCA measured at the photoelctron takeoff angles of 15° and 90°, the graft copolymerization was suggested to proceed into a deep layer from a surface thin layer (below 2 nm) with low grafting. A grafting of 150% from 15°-measurement (the sampling depth of ca. 2nm) or 500% from 90°-measurement (the sampling depth of ca. 8 nm) was found to result in an antithrombogenic surface superior to the original one and also the grafted surface with the lowest contact angle of 26°.View full abstractDownload PDF (2076K) -
Hiroshi TAODA, Kiyoshi HAYAKAWA, Kaoru KAWASE, Masato TAZAWA, Hiromi Y ...1987 Volume 44 Issue 6 Pages 437-444
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to realize the photochemical conversion and storage system of solar energy based on the reversible valence isomerization of norbornadiene to quadricyclene, polymer-anchored cobalt catalysts were synthesized and their properties were examined for the isomerization of quadricyclene to norbornadiene. Polymeranchored cobalt catalysts were prepared by graft-copolymerizing chloromethylstyrene onto porous polyethylene, cellulose acetate and glass fibers and then making ester linkages between the chloromethyl groups and carboxyl groups of cobalt porphine. The resulting catalysts were highly active, easily handled and very stable in the isomerization of quadricyclene to norbornadiene compared with monomeric cobalt porphines.View full abstractDownload PDF (1303K) -
Toshimasa HASHIMOTO, Kei OKUNO, Mizuho KINOSHITA, Akira TAKAKU1987 Volume 44 Issue 6 Pages 445-449
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe thermal diffusivity of poly (α-chloroacrylonitrile) (PCAN) films heat-treated at temperatures from 140°C to 1300°C was measured by a photoacoustic method. Measurements were also made of infrared spectrum and electrical conductivity. The thermal diffusivity of PCAN film did not change by heat-treatment at temperatures below 600°C, but increased above 700°C from a value of 4×10-7 m2/s for the untreated film to a value of 2×10-6 m2/s for the film heat-treated at 1300°C. IR spectra showed that the formation of carboneous structure becomes evident by heat-treatment above 700°C This indicates that the increase in thermal diffusivity is due to the development of graphite-like layers. The correlation between the changes in thermal conductivity and electrical conductivity did not fit Wiedemann-Franz's low. It was concluded that the carriers in the PCAN pyrolyzates investigated are not electrons but phonons.View full abstractDownload PDF (928K) -
Yoshiyuki IKEDA, Kazuko KASHIWAI, Yukio KURA, Yoshikazu SHIMIZU, Hiden ...1987 Volume 44 Issue 6 Pages 451-460
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe hydrogen transfer polymerization of crotonamide (CAm) and tiglinamide (TAm) catalyzed by sodium naphthalene (Na-Naph) was studied under various conditions. Pyridine, xylene and chlorobenzene served as good solvents in the polymerization of CAm, whereas, non-polar solvents such as xylene and toluene in the polymerization of TAm. The reaction products were mainly poly (β-amino acid) s in all systems. The initiation reaction in both the CAm and TAm polymerizations was abstraction of a proton from the amide end group. The propagation reaction of the CAm polymerization in pyridine mainly proceeds stepwisely and that of CAm in xylene and that of TAm in xylene or pyridine predominantly proceed by chain reaction. The hydrogen transfer polymerization rates of CAm, TAm, acrylamide (AAm) and methacrylamide (MAAm) in pyridine were in the following order. AAm>CAm>MAAm>TAm. The polymerization of N-substituted acrylamides and their derivatives were also investigated.View full abstractDownload PDF (1454K) -
Hiroshi OHMURA, Takashi YAMAMOTO1987 Volume 44 Issue 6 Pages 461-468
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNew block copolymers of a non aqueous dispersion type which had both the hydrocarbon-soluble and -insoluble segments and were soluble or dispersible in non-aromatic solvents were synthesized with polymeric peroxides. Poly (2-ethylhexyl methacrylate-block-methyl methacrylate) is an example. A polymerization process to prepare stable dispersions of low viscosity and high solid content was established by selecting appropriate monomers, molecular weights of block polymer and solvents of appropriate solubility parameters. It became possible to prepare non aqueous dispersion polymers which have high content of insoluble polymer segment (over 80 wt%) and high solid content in dispersion (65 wt%) in contrast with 60 to 70 wt% and 50 wt%, respectively, of conventional non aqueous dispersion polymers. Viscosities of non aqueous dispersions could be determined by the modified Mooney equation.View full abstractDownload PDF (1365K) -
Akira UEDA, Susumu NAGAI1987 Volume 44 Issue 6 Pages 469-475
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPoly (hexamethylene azobiscyanopentanoate) (PHMACP*), which had an easily scissile -N=N- linkage in every repeating unit, was prepared at room temperature by polycondensation of azobis (cyanopentanoyl chloride) and 1, 6-hexanediol. PHMACP* was used as macro-azo-initiator for the synthesis of poly (methyl methacrylate) -poly (n-butyl acrylate) block copolymers (PMMA-b-PBA) by the two-step radical polymerization. Thus, PHMACP* was partially decomposed in the presence of methyl methacrylate (MMA) to initiate the polymerization of MMA from the chain ends of PHMACP* fragments. Poly (methyl methacrylate) (PMMA*), containing unreacted -N=N- linkages on its segment ends, was then completely decomposed in the presence of n-butyl acrylate (BA) to initiate the polymerization of BA from the chain ends (PHMACP* fragments) of PMMA*. The rate of BA consumption (Rp) was proportional to [BA] 1.5. The poly (n-butyl acrylate) (PBA) content of block copolymers was changed from 2% to 69% by changing the BA feed concentration. The molecular weights and turbidimetric titration curves of block copolymers were determined.View full abstractDownload PDF (1226K) -
Hiroshi SAKAMI1987 Volume 44 Issue 6 Pages 477-482
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSLinear polyethylene of high molecular weight (Mw=6×105) formed micro-fibrils when it was crystallized above the melting point under suitable stretching. The fibrils thus obtained have circular cross-section and even surface. The changes of surface structure of these fibrils by heat treatment were investigated by means of the electron microscopies (TEM, SEM), differential scanning calorimetry (DSC), and X-ray diffractions (WAXD, SAXD). By the heat treatment at the temperature close to the melting point, the long period of crystals of oriented direction observed on SAXD and TEM was increased from 500 Å to 860 Å. It was found that the crystals on a surface layer of the high oriented fibrils grew in the direction parallel to the oriented direction, while the crystallites of lowly oriented fibrils disordered with decreasing in the rate and ratio of stretching. In a surface layer of these low oriented fibrils, unevenness owing to many crystallites was observed. It is concluded that the larger surface area on this fibril resulted from the unevenness of irregular crystallites in the surface layers.View full abstractDownload PDF (1834K) -
Kunio FURUSAWA, Chikai ANZAI1987 Volume 44 Issue 6 Pages 483-489
Published: June 25, 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe properties of heterocoagulations consisting of monodispersed amphoteric latices with a diameter or 250 nm and much larger spherical silica (diameter, 1590nm) of narrow size distribution, were investigated as a function of pH, particle number concentration, the ratio of their concentrations and ionic concentration. Under a suitable mixing condition, ie., the condition including dilute silica particles and a large excess of the latex particles of dissimilar charge, a stable system consisting of composite particles formed by the regular deposition of the latex particles on the silica can be prepared. Analyses of the conditions for forming such a regular heterocoagulation and of the properties of the products have been done using the theories of D.L.V.O. and heterocoagulation.View full abstractDownload PDF (1428K) -
1987 Volume 44 Issue 6 Pages i
Published: 1987
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDownload PDF (58K)
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