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Volume 47, Issue 3
Displaying 1-12 of 12 articles from this issue
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Junji NAKAGI, Kazuo KAMAGATA, Nobuaki AWANO1990 Volume 47 Issue 3 Pages 169-175
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESS1, 3, 5-Triglycidyl-s-triazinetrione synthesized from isocyanuric acid with epichlorohydrine was a mixture of crystals, a and β forms, having melting points at about 100 and 150°C, respectively; their crystals were stereoisomeric isomers. The thermal behavior and chemical reactivities of isomers were studied using differential thermal analysis. Endothermic peaks due to fusion appear at about 100 and 150°C in their DTA curves; subsequent heating gave no endothermic peak. An a form crystal which was kept at room temperature for 1 day gave a endothermic peak at about 100°C. On the other hand, a β form crystal which was kept at room temperature for 10 days gave no endothermic peak. It is assumed that molecular conformations and crystal packing arrangements of a and β forms are very different. Activation energies calculated according to the Kissinger method are 132 kJ mol-1 for a form and 2-methylimidazole (1) and 163 kJ mol-1 for β form and 1. The activation energies for a and β forms which were cured with methylhexahydrophthallic anhydride were 130 and 136 kJ mol-1, respectively.View full abstractDownload PDF (954K) -
Satoshi MATSUMOTO, Kazutoshi IKENAGA, Katsumi MIYAMURA1990 Volume 47 Issue 3 Pages 177-184
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSComposite esters were prepared from dibutyl or di (2-ethylhexyl) adipate and diols by the ester interchange reaction using a titanium catalyst. Composition and viscosity of the esters were dependent on the molar ratio of reactants. Complex esters such as ethanediylbisbutyl adipate, 12-propanediylbisbutyl adipate, and 13-butanediylbisbutyl adipate were purified by distillation. These composite esters were tested as plasticizers, and plasticizing efficiency was evaluated from the hardness of the sheets. They have very low volatility and good plasticizing efficiency in comparison with commercial plasticizers. Mechanical properties of the shaped materials with composite ester plasticizers were superior to those with commercial plasticizers at the same level of hardness, and films or sheets with similar properties may be obtained with the composite ester plasticizers whose amounts corresponded to 80-90% amount of DOP.View full abstractDownload PDF (1722K) -
Mitsukazu OCHI, Tatsuya KAWABATA, Kiichi YAMASHITA, Masaki SHIMBO, Tat ...1990 Volume 47 Issue 3 Pages 185-191
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBisphenol-A type epoxide resin was modified with two kinds of silicone elastomers, i. e., amino-terminated polysiloxane (ATPS) and polydimethylsilanol (PDMS). Both systems modified with the silicone elastomers had two phase structures in which the silicone phase is dispersed in the cured epoxide resin matrix. A swelling test for uncured resins showed that the silicone phase in the ATPS-modified system has no crosslinks and the phase in the PDMS-modified system forms a crosslinked structure. Internal stresses of the unmodified and ATPS-modified systems were linearly increased with a decrease of the ambient temperature in cooling process. The internal stress of the PDMS-modified system was linearly increased in the beginning of cooling process, but decreased abruptly when the temperature reached near 70°C. Thus, the internal stress at room temperature of this system was considerably lower than that of other systems. In addition, the expansion of cured resin was abnormally observed at about 70°C in the cooling process of the PDMS-modified system. The decrease of internal stress in this system is attributed to the expansion phenomenon observed during the cooling processView full abstractDownload PDF (1945K) -
Kazuo SASAKI, Michio SASAKI1990 Volume 47 Issue 3 Pages 193-196
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSUnder the application of a stepwise external force in the direction of the thickness of poly (vinylidene fluoride) film, a transient change in piezoelectric voltage has been measured; this change was found to be proportional to the external force. In this measurement, an applied force was generated by the spring-balanced metallic anvil with a tip of 0.09cm radius of curvature, close to the radius of a pin point. The transient change in voltage was due to the time constant of the measurement system including a specimen. Based on such observed results and the attenuation behavior of the piezoelectric voltage, the piezoelectric constant of poly (vinylidene fluoride) film could be determined in the direction of thickness. The value of d33 was -26.5×10-12C/N.View full abstractDownload PDF (1099K) -
Takeo IIDA, Hirohisa IKEDA, Hiroshi YOSHIDA, Kunio GOTO1990 Volume 47 Issue 3 Pages 197-205
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSEffects of synergetic combination of poly (vinyl alcohol) s (PVA) and zinc stearate/calcium stearate soap on the thermal stabilization of poly (vinyl chloride) (PVC) were investigated by colorimetry. Synergetic effect between PVA and synergetic metal soap was markedly enhanced by adding PVA which was lower polymerization degrees as an aqueous solution, while any measurable effects were not observed by compounding PVA as a solid. Area and NCG (distance to nearest center of gravity) as for PVA particles in the compounded PVC sheet specimens were measured by using a personal image processing system to evaluate the dispersion degree of PVA. The enhancement of stabilization of PVC markedly depends on the dispersion degree of PVA in the compounded PVC. Namely, the fine dispersion of PVA was observed in the systems exhibiting good effects. The image processor was a useful instrument to evaluate dispersion degree of additives in plastic materials.View full abstractDownload PDF (1336K) -
Rikio YOKOTA, Takahiro SAKINO, Itaru MITA1990 Volume 47 Issue 3 Pages 207-214
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThermogravimetric curves of four aromatic polymers: poly (ether ether ketone), polysulfone, polyethersulfone and polyparaxylirene, and nine aromatic polyimides have been obtained in nitrogen flow. The initial degradation temperature and the weight residue at 700°C in these curves have been analyzed. In addition, the activation energies for each conversion of degradation were determined from thermogravimetric curves of each polymer at various heating rates. The polyimides with substituted aromatic rings start weight losses at lower temperatures. The wholly aromatic polyimide has the highest thermostability. TG curves of polyimides change gradually up to 700°C resulting in higher weight residue, but TG curves of aromatic polymers show steep weight losses, resulting in low weight residues at 700°C. Thermal stability of these polymers roughly depend on the weakest chemical bonds in the polymer main chains. The activation energies of aromatic polymers were determined, the value was 75 kcal/mol for poly (ether ether ketone) and 50kcal/mol for polyparaxylirene. On the other hand, the activation energy on polyimides increases to the higher value during thermal degradation, resulting in a linear correlation between E and the degradation temperatures.View full abstractDownload PDF (1560K) -
Jojiro OKUMURA, Masayuki KISHIBE, Koichi YAMAGUCHI1990 Volume 47 Issue 3 Pages 215-221
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe modification of styrene-butadiene block copolymer (SBS) was carried out by the graft polymerization of various methacrylic esters or acrylic esters. The effects of degree of grafting, glass trandition temperature (Tg) of the polymer of graft chain, morphology on mechanical properties of the resulting graft polymers were investigated. The graft polymers having the graft chain of high Tg had better tensile and tear properties. The graft polymers with methyl methacrylate had extremely high tensile strength and modulus at low degree of grafting (about 5%). From dynamic viscoelastic behavior patterns, it was found that the graft chain was compatible with polystyrene segment at low degree of grafting, or in the case of graft chain having low Tg and similar solubility parameter as that of polystyrene. The microdomain structure of graft polymers and the ratio of surface area of polystyrene domain differed with cast solvents, but tensile strength was almost constant. These results confirmed that the graft polymers had high tensile strength and modulus because the graft chain and polystyrene segment were compatible and had a phycical crosslinkage at low degrees of grafting.View full abstractDownload PDF (1742K) -
Jojiro OKUMURA, Kiyomitsu KITAIDE, Koichi YAMAGUCHI1990 Volume 47 Issue 3 Pages 223-230
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSModification of a styrene-isoprene block copolymer (SIS) was attempted by graft reaction of poly (methyl methacrylate) (MMA) macromonomers (McMMA) or graft polymerization of MMA, and their adhesive and mechanical properties were investigated. The degree of grafting and the graft efficiency in graft reaction of McMMA onto SIS decreased with increasing molecular weight (Mn) of McMMA. The degree of grafting in grafting of McMMA or MMA onto SIS increased with increasing concentration and reaction time. For the bonding between styrenebutadiene block copolymer and plasticized poly (vinyl chloride) sheets, it was found that the peel strength had a maximum against the degree of grafting. The position of the maximum of the graft polymer with McMMA (SIS-g-McMMA) shifted to the lower degree of grafting, namely the smaller number (n) of graft chain, with increasing Mn. Particularly, SIS-g-McMMA had better peel strength than the graft polymer with MMA (SIS-g-MMA), in which Mn was more than 10000 and n was less than 2. The optimum Mn and n of SIS-g-McMMA for tensile strength were more than 10000, and 0.5-2, respectively. The tensile strength of SIS-g-MMA decreased with increasing degree of grafting. From these results, it was confirmed that better adhesive and mechanical properties could be achieved with SIS-g-McMMA than SIS-g-MMA by controlling both Mn and n.View full abstractDownload PDF (1388K) -
Sadao SATO, Tadashi KIKUCHI, Keiichi KUMAGAI, Yasushi OYANAGI1990 Volume 47 Issue 3 Pages 231-236
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAn apparatus with a probe which can measure the thermal conductivity of molten polymers was constructed. The performance of the device and the temperature dependence of the thermal conductivity of various polymers were investigated. In order to apply the computer analysis and the computer aided engineering (CAE), the effects of the heat transfer by radiation on the thermal conductivity of molten polymers were studied. The optimum thermal conductivity on the mold flow was also analyzed. The thermal conductivity values of polymers in the solid phase were 0.16-0.18 kcal/m·h·°C. The thermal conductivity of the polymers increased with increasing temperature. The thermal conductivity of the molten polymers eventually became ca. 39% larger than that of the solid polymers. A discontinuity of the thermal conductivity was observed at the melting temperature Tm and at the glass transition temperature Tg. The amount of heat transfer by radiation of molten polyethylene, polycarbonate, and polyoxymethylene was ca. 8-14% of the total value of heater. The heat transfer by radiation was considered in the thermal conductivity analysis with a computer and the CAE. The accuracy of measurement was within ± 3-4% in the molten state polymers. This value is ca. 7% higher than that measured using a concentric cylinder device.View full abstractDownload PDF (914K) -
Tadahiko TAKATA, Masashi FURUKAWA1990 Volume 47 Issue 3 Pages 237-244
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSUsing radio-frequency ion-plating (RFIP), Nylon 6, a representative polycondensation polymer, was made into film. The process involved creating the plasma condition under 10-4 to 10-3 Torr vacuum and evaporating molten Nylon 6 in the plasma this process formed on the substrate a film which was different from that produced in the normal vacuum evaporation technique. The deposits formed by the simple vacuum evaporation technique dissolved in nylon solvents such as formic acid, m-cresol or hydrochloric amide, but film did not form. The RFIP technique formed film consisting of formic acid soluble and insoluble components. The results of IR, thermal, X-ray diffraction, elementary, and other analyses showed that the film was made of crosslinked and uncrosslinked low-molecular weight nylon having a structure different from but similar to the original Nylon 6 structure.View full abstractDownload PDF (2115K) -
Tadahiko TAKATA, Masashi FURUKAWA1990 Volume 47 Issue 3 Pages 245-253
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPhysical treatment procedures were investigated as surface activation techniques of high polymers with inactive surface. In this research, treatments by electron beam, ultraviolet ray, and low-temperature plasma were investigated; PET film was treated and changes in the surface, microstructure, and mechanical properties were investigated. Investigation results showed that among these techniques the low-temperature plasma technique activated the inactive surface by etching the surface and introducing the functional group without impairing the inherent mechanical properties. Because the electron beam technique deteriorates the mechanical properties, it is very restricted as a surface improvement technique. The deterioration of mechanical properties by the ultraviolet ray technique was relatively small. Adhesion with the martrix was recognized to improve irrespective of the techniques employed.View full abstractDownload PDF (1484K) -
Shinnosuke MIYAUCH, Masaru SHIBASAWA, Yoshio SORIMACHI, Ichiro TSUBATA1990 Volume 47 Issue 3 Pages 255-260
Published: March 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSFour kinds of polythiophene with different conductivity were prepared by polymerizing thiophene electrochemically at low temperatures in a range of 10--20°C. DC conductivities in both a plane direction and a vertical direction were measured between -140 and 120°C. The conductivity in the plane direction was larger than that in the vertical direction by orders. Temperature dependencies of the conductivity were related to 1/T1 (n+1) rather than 1/T, in particular, n was 3 for the conductivities in the vertical direction and for low conductivities in the plane direction in the samples prepared at relatively high temperatures. AC conductivities were also measured between 10 kHz and 1 MHz at various temperatures. For the samples prepared at low temperatures, the conductivity in the plane direction was almost independent of the frequency. On the other hand, the conductivity in the plane direction for the samples prepared at comparatively high temperatures, or the conductivity in the vertical direction was somewhat dependent on the temperature at 1 MHz. These results are explained by Mott's hopping model.View full abstractDownload PDF (1169K)
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