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Volume 47, Issue 12
Displaying 1-14 of 14 articles from this issue
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Kunio URUSHIDO, Toshifumi ARAI, Satoshi KURIBAYASHI, Madoka KOBAYASHI1990 Volume 47 Issue 12 Pages 939-944
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSHomo-and copolymerizations of N-allylisomaleimide (AIMI) and N-allylisocitraconimide (AICI) were carried out at 60°C by using azobisisobutyronitrile as the initiator. The rate of the polymerization of AIMI was estimated to be 6.34×10-6mol·l-1·s-1, about 4.7 times higher than 1.35×10-6mol·l-1·s-1 for AICI, which has an α-methyl group. Compared with AIMI, AICI showed a high degree of cyclization in the polymerization. In the copolymerization of AIMI or AICI (M1) with styrene (M2), the mole fraction of M1 in the copolymer is less than 0.5 over the whole range of the feed monomer composition. All the isomaleic and isocitraconic double bonds participated in copolymerization, whereas the allylic double bonds remained intact.View full abstractDownload PDF (900K) -
Kazuhiro TANAKA, Hidetoshi KITA, Ken-ichi OKAMOTO1990 Volume 47 Issue 12 Pages 945-951
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSGas permeability and permselectivity of commercially available polyimides were investigated at 35°C and 100°C and compared with those of other glassy polymers. The polyimide perpared from 3, 3′, 4, 4′-benzophenonetetracarboxylic dianhydride (BTDA) and two different diamines, 4, 4′-methylenedianiline (MDA) and 2, 6-diaminotoluene (BTDA-M/T, commercially available as PI-2080), and the polyimide from 2, 3, 5-tricarboxycyclopentyl acetic acid dianhydride (TCDA) and 4, 4′-oxydianiline (ODA) had excellent permeability and permselectivity for H2/CO and H2/CH4 systems (PH2=1×10-9cm3 (STP) cm-1 s-1 cmHg-1, PH2/PCO=100, PH2/PCH4= 500 at 35°C). The polyimide prepared from BTDA and 3, 3′-diaminobenzophenone (commercially available as LARC-TPI) had lower permeability and much higher permselectivity (PH2=2×10-10cm3 (STP) cm-1 s-1cmHg-1, PH2/PCO=350, PH2/PCH4= 1400 at 35°C). Three polyimides containing two ether linkages in the diamine moiety had poor permeability and permselectivity as compared with the above-mentioned polyimides. These results were discussed in terms of packing density and local mobility. All polyimides investigated were not attractive as membane materials for CO2/CH4 separation because of low permeability for CO2. In a BTDA-M/T film, 2% residual dimethylacetamide solvent caused about 30% reductions in permselectivities for H2/CO and H2/CH4 without an appreciable increase in PH2 as a result of the plasticization effect.View full abstractDownload PDF (1319K) -
Radical Cyclopolymerization of Ethyl Vinyl CitraconateIwao TAKASE, Koji HIROSE, Hiroshi AIDA1990 Volume 47 Issue 12 Pages 953-959
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAs a further study on the preparation of polymers containing 4-membered lactone units along the main chain, radical cyclopolymerization of ethyl vinyl citraconate (EVC) was carried out in benzene at 70°C. The preparation of EVC led to two isomers [CH2=CHOCOC (CH3) =CHCOOC2H5 and CH2=CHOCOCH=C (CH3) COOC2H5; 1.15: 1 mol ratio], which could not be separated by distillation or chromatography. Therefore, they were used for the polymerization without separation. The polymerization at a concentration lower than 0.5 mol/l of EVC gave polymers containing two types of β-lactone units; i. e., β-propiolactone and α-methyl-β-propiolactone (6: 4 ratio). The polymers contained a trace of residual unsaturation where the pendant citraconic double bonds were 2.7-3 times the pendant vinyl groups. This result suggests the degradative chain transfer to the methyl group on the carbon-carbon double bond of EVC.View full abstractDownload PDF (1153K) -
Toshio KUNUGI, Akihiro SUZUKI, Jun ITODA1990 Volume 47 Issue 12 Pages 961-965
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe zone-annealing method has been applied to improve the mechanical properties of a commercially available polyether ether ketone (PEEK) fiber. The zone-annealing was repeated five times with increasing the heating temperature and applied tension. The final zone-annealed fiber had Young's modulus of 11.7 GPa and a tensile strength of 1.11 GPa. These values are about twice those of the commercially available PEEK fiber used as the starting material. The dynamic modulus increased with repeating zone-annealing, and that of the final zone-annealed fiber was 13 GPa at room temperature and 3 GPa even at 280°C. These values are notably higher than 7 GPa and 0.5 GPa of the starting material. The maximum birefringence was 0.316, which is close to a theoretical intrinsic birefringence of 0.34. Further, the birefringences of amorphous phase were calculated from the measured birefringence by the equation expressed as the sum of crystalline and amorphous birefringences. The birefringence of amorphous phase was directly proportional to Young's modulus. The crysallinity increased from 28% to 40% by zone-annealing. However the orientation factor and sizes of crystallites showed almost no change by zone-annealing. The improvements of the mechanical properties were considered to be attributed to highly oriented amorphous chains which are constrained by a lot of crystallites.View full abstractDownload PDF (1006K) -
Hiroshi KAWABE, Masakazu SUZUKI1990 Volume 47 Issue 12 Pages 967-971
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effects of addition of protic solvents on the amination of chloromethylated polystyrene (CMPS) and benzyl chloride (BC) with s-butylamine were investigated. The reaction rates of BC in pure alcohols were closely related with their electrostatic effects, and the similar trend was observed in regard to the rates of CMPS and BC in dioxane containing alcohols. This relation was, however, not observed in dioxane containing other protic solvents. The ratio kP/kB tends to decrease when the rate increases by the addition of protic solvents, where kP and kB are the rate constants for CMPS and BC, respectively. The activation enthalpy (ΔH≠) and entpropy (ΔS≠) of the reaction with BC in pure alcohols are much higher than those in dioxane. The type of dependence of log kB on the solvent composition in a binary solvent system of dioxane and alcohol suggests that both the reactant (amine) and the transition state are solvated specially by hydrogen bonding.View full abstractDownload PDF (800K) -
Ken-ichi FUJIWARA, Toshiro MASUDA, Masaoki TAKAHASHI1990 Volume 47 Issue 12 Pages 973-976
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA series of well known thermotropic liquid crystalline random copolyesters which were synthesized from poly (ethylene terephthalate) and 60 mol% p-hydroxybenzonic acid was characterized with respect to the weight average molecular weight Mw by sedimentation equilibrium of the dilute solution in 1, 1, 1, 3, 3, 3-hexafluoro-2-propanol as well as the intrinsic viscosity ([η]) in a mixture of phenol/1, 1, 2, 2-tetrachloroethane (1: 1 by weight). The following Mark-Houwink-Sakurada relation was established: [η] =1.30×10-3Mw0.67 at 30°C. The Flory K value of 3.6×10-3 was obtained by the method of Stockmayer-Fixman. The characteristic ratio of the copolyesters was close to that of poly (ethylene terephthalate), suggesting that the chain of the copolyesters is as flexible as that of poly (ethylene terephtalate) in the solution state.View full abstractDownload PDF (609K) -
Eiji KUCHIKI, Akira KIDOGUCHI, Hideki NAKANISHI, Toshiyuki WATANABE, S ...1990 Volume 47 Issue 12 Pages 977-984
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe relationship between the morphology and Second Harmonic Generation (SHG) intensity in aliphatic polyester/para-nitroaniline (p-NA) systems showing high SHG efficiency was studied by morphology observation with polarizing microscopy and SHG intensity measurement. These systems are composite systems distributing p-NA microcrystals in the crystalline polymer matrix. The crystallization process is affected dramatically by the p-NA component and temperature, and the SHG active phase is produced with a specified crystallization process. Therefore, the SHG intensity observed from aliphatic polyester/p-NA systems strongly depends on the p-NA composition and crystallization temperature, and SHG activity can be seen only on specified morphologies.View full abstractDownload PDF (3340K) -
Kazuhiko MAEDA, Shigeru TASAKA, Norihiro INAGAKI1990 Volume 47 Issue 12 Pages 985-988
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe compatibility in the mixtures of poly (vinylidenefluroide-co-hexafluoroacetone) (VDF-HFA) and polyacrylates was investigated. The glass transition temperature (Tg) was measured by the dynamic mechanical analysis and the cloud point was measured by the optical transmittance. The polyacrylates having an alkyl group with fewer than four carbon atoms are miscible with P (VDF-HFA). These mixtures showed the lower critical solution temperature (LCST) type phase behavior. In these systems, the ratio of Tg and LCST was found to be between 0.55 and 0.67.View full abstractDownload PDF (561K) -
Akira TANAKA, Yuji KOJIMA1990 Volume 47 Issue 12 Pages 989-991
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe retardation of the compact discs have been measured for poly (vinylidene fluoride) (PVDF) and poly (methyl methacrylate) (PMMA) blends in relation to applications to the erasable optical disc. The compact discs were formed using an injection molding machine at PVDF concentrations up to 20%. The effect of PVDF on retardation was almost zero at the vicinity of the circumference of a substrate at PVDF concentrations up to 20%. On the other hand, the retardation at the center of a substrate was minimum when the PVDF concentration is 10% and almost equal to the pure PMMA substrate.View full abstractDownload PDF (396K) -
Akira TANAKA, Yuji KOJIMA, Hisashi SAWADA1990 Volume 47 Issue 12 Pages 993-996
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA flat plastic optical fiber with a polycarbonate core has been studies to control the polarized laser. The output light power from the fiber terminal is maximum when the direction of the polarized light coincides with the long axis of the cross-section of the fiber. This fiber can hold the polarized light and can convert from the circularly polarized laser to the polarized light.View full abstractDownload PDF (480K) -
Jinichiro KATO, Yoshimi KURODA, Katsuyuki NAKAMURA1990 Volume 47 Issue 12 Pages 997-1000
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESS1, 6-Diacrylate-2, 4-hexadiyne (DAHD) yields quite rigid cured products with high modulus and Vickers hardness values. Accordingly, the composite materials made from DAHD and various fillers are expected to be high performance materials with even more excellent properties. Graft polymerization initiated by azo groups introduced ontotitanium oxide was investigated by using the reactivity of DAHD. Graft polymerization proceeded smoothly and the percentage of grafting reached 175.1% as a maximum value. DAHD grafted titanium oxide and DAHD were molded in order to develop rigid materials. The obtained moldings have a quite high modulus value of 54.3 GPa.View full abstractDownload PDF (671K) -
Shuji IKOMA, Eigo NOMOTO, Hiroshi YOKOI1990 Volume 47 Issue 12 Pages 1001-1004
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA new type of poly (vinyl alcohol) (PVA) -silica composite hydrogels was prepared by freezing and thawing. The gels were elastic, not adhesive and opaque in water, but transparent in organic solvents. The amount of silicic acid eluted from the gel with water was extremely small. The rate of dehydration of the gels was lower than that of the PVA hydrogel. The composite hydrogels prepared showed improved mechanical and rheological properties. This may be associated with the microscopic bond-formation between two constituents of the gel.View full abstractDownload PDF (1167K) -
Ryoichi MURAKAMI, Yoshiaki MOTOZATO1990 Volume 47 Issue 12 Pages 1005-1006
Published: December 25, 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThis study is concerned with the concentric-circular patterns exhibited on the spherical beads of poly (vinyl acetate) during saponification. The saponification was carried out by immersing the spherical beads in a solution containing sodium hydroxide and methanol in an aqueous saturated sodium sulfate solution. The patterns develop slowly from the outer part of the sphere to the inner part with the progress of saponification. Intervals of the patterns depend on the conditions of saponification.View full abstractDownload PDF (720K) -
1990 Volume 47 Issue 12 Pages xvii
Published: 1990
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDownload PDF (136K)
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