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Predecessor
Volume 49, Issue 3
Displaying 1-12 of 12 articles from this issue
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Naoto MIFUNE, Yasutaka NAGAI, Kiichi TAKEMOTO1992 Volume 49 Issue 3 Pages 169-173
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe relationships between viscoelastic properties and dynamic properties such as swollen network density, tensile strength, and elongation at break were investigated. The samples were Rubber Sandwich Couplings used as anti-vibration rubber on Japan Railways vehicles for about two years. The relationships between normalized maximum loss factors and normalized values of these properties can be expressed by first-order equations.View full abstractDownload PDF (765K) -
Xiuxun WANG, Hiromu SAITO, Takashi INOUE1992 Volume 49 Issue 3 Pages 175-179
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe investigated the morphology of binary mixtures of polyoxymethylene (POM) and Novolak resin crystallized at various temperatures. At high degrees of supercooling, the spherulite was found to develop, while a mixed morphology of Hedrite and Ovoid appeared at low degrees of supercooling. As the Novolak resin content increased, the morphology transition from spherulite to the mixed morphology took place at a lower temperature. When we compared the morphological results with those of crystallization kinetics, we found that the morphology transition was not caused by the difference in growth regime but it depended on the magnitude of the growth rate G, i. e., high G (>2.75×10-7m/s) yielded spherulites.View full abstractDownload PDF (1605K) -
Fumiaki KAWAKAMI, Kunihiko TAKEDA, Keishi TADA1992 Volume 49 Issue 3 Pages 181-187
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAs part of a series of studies on the characteristics of crosslinked polymers as a reaction arena in sulfonation, the spherical crosslinked polymer was sulfonated at various temperatures after through swelling by an effective swelling agent. The rate-determining step was found to be local reaction at low temperatures, and sulfonating agent diffusion at temperatures of 40°C or higher. The sulfonation proceeded from the particle surface region so that the sulfonic groups occupied a spherical shell having a thickness determined by reaction time and temperature. The results thus indicate that the rate of the sulfonating agent diffusion is decreased by collisions or other interactions between its molecules and the molecular chains of the crosslinked polymer network.View full abstractDownload PDF (1818K) -
Fumiaki KAWAKAMI, Keishi TADA, Kunihiko TAKEDA1992 Volume 49 Issue 3 Pages 189-196
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAs part of a series of studies on the characteristics of crosslinked polymers as a reaction arena in sulfonation, the crosslinked polymer was pre-swelled by exposure to tetrachloroethylene for 0-120 min and then subjected to sulfonation by chlorosulfonic acid at various temperatures and reaction times. The distribution of the sulfonic group in the polymer was found to vary markedly with the pre-swelling conditions, and was limited to a thin-shell surface layer when pre-swelling for 20 min at 25°C and sulfonation at 0°C were employed. Swelling and reaction rate analyses indicate that the spatial progress of sulfonation in a crosslinked polymer can be be specifically controlled by utilization of the slow interaction between the rigid polymer network and the swelling agent. This control can be employed effectively for further elucidation of the crosslinked polymer as a reaction arena.View full abstractDownload PDF (2303K) -
Masaki YOSHII, Hiroki KURAMOTO1992 Volume 49 Issue 3 Pages 197-204
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIn order to analyze the mechanism of the transcription in injection-molding and signal deterioration of optical discs, the relationship between the mold temperature and the surface roughness of the polycarbonate and amorphous polyolefin substrate has been studied. The results obtained are as follows; (1) When the mold temperature is low, microscopic flow marks more than 5 nm deep are formed on the surface of the injection-molded substrate, and the molding transcription drops. (2) When the mold temperature is high, the flow marks disappear, and at the same time the molding transcription improves. The surface roughness of the substrate of 3.2 nm in Rmax is nearly equal to that of the stamper of 2.7 nm in Rmax (3) The signal deterioration of the optical disc strongly depends on the surface roughness of the substrate. That is, the noise power becomes lower when the surface becomes smoother.View full abstractDownload PDF (2154K) -
Koji MORI, Kenji KOSHIISHI, Ken-ichi MASUHARA1992 Volume 49 Issue 3 Pages 205-212
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSElectron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate (MMA) and methacrylic acid (MAAc) blended with solvents, which have different solubility parameters δ, onto high density polyethylene films (PE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic rations on the surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of solvents, and grafting rates for MMA were larger than those for MAAc. Graft chain contents on the surface, which were evaluated in terms of surface tensions and atomic ratios on the surface, increased with increasing δ of solvents, and graft chain contents on the surface of MAAc grafted PE were higher than those of MMA grafted PE. It is assumed that mutual solubility of PE and solvents (monomer solutions), i. e., infiltration of monomer solutions into PE during graft-polymerization, influenced grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films.View full abstractDownload PDF (1905K) -
Sinichi SATO, Hisao NOJIRI, Toshinao OKITSU, Tohru WAINAI1992 Volume 49 Issue 3 Pages 213-219
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBy reacting N, N′-4, 4′-diphenyl-methane-bismaleimide (BMI) and bisphenol A type epoxy resin (Ep828) in the presence of glycidol (GD) at 140°Cfor 2 hours, a homogeneous liquid was obtained (nearly 100% of BMI reacted, and about 20% of GD reacted). This liquid provided good storage-stability. For investigating this reaction, N-phenylmaleimide (PMI), phenyl glycidyl ether (PGE), and GD were selected as model compounds. Two main reactions were recognized. One was the anionic polymerization {GD (PMI) n} caused by Michael addition reaction between PMI and GD and the other was the radical polymerization { (PMI) n} initiated by the charge-transfer complex formed between PMI and GD. PGE reacted only very little, under 1%, but it acted as a chain transfer agent. The reactions of BMI and GD were the main reactions. The products of these reactions coexisted with unreacted Ep828 and GD in a state of good compatibility. In the case of curing these products with 2-ethyl-4-methyl imidazole, GD acted as a hardening accelerator.View full abstractDownload PDF (912K) -
Seiji SAITA, Noritsugu UCHIDA, Tadatomi NISHIKUBO1992 Volume 49 Issue 3 Pages 221-228
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPolymers containing various phenyl ester groups and quaternary ammonium salt residues as catalysts were synthesized by the radical copolymerization of phenyl methacrylates with trimethy1-3- (propenoylamino) propylammonium chloride (TMPAP), and the self-catalyzed thermo-crosslinking reaction of the films composed of the obtained polymers and poly-functional epoxy compounds was investigated. The rate of gel production of the copolymer was strongly dependent on the kind of phenyl ester groups in the copolymer, and was facilitated by electron-withdrawing groups such as p-nitro or p-chloro groups on the phenoxide. Furthermore, it was found that the rate of gel production of copolymers was strongly affected by the reaction temperature, the amount of phenyl methacrylate component in the copolymer, the amount of TMPAP component in the copolymer, and the structure of poly-functional epoxy compounds.View full abstractDownload PDF (1295K) -
Tomiwo TATSUMI, Eiko ITO1992 Volume 49 Issue 3 Pages 229-233
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSComplex permittivities for a series of linear aromatic polyesters which have 2, 4, 6, and 10 carbon atoms in glycol residues have been measured. β-Relaxation was observed for all the samples. The loss peaks for a series of polyesters shift to lower temperatures with an increase in the glycol residues length. The molecular motion contributing to the β-relaxation strongly depends on the number of carbon atoms in the glycol residues. Moreover, the asymmetric shape of β-loss curves changes with an increase in the glycol residues length. The β-loss was, however, observed as only one peak for all the polyesters. The change in the asymmetric shape of the β-loss spectra was also observed in the frequency dispersions of the dielectric loss. The β-relaxation peak was therefore considered to consist of one component, and the asymmetry of the loss spectra is inherent to the relaxation mechanism of these polymers. These results suggest that dielectric β-relaxation of aromatic polyesters is attributed to torsional vibrations of the main chain in the neighborhood of the local equilibrium conformation.View full abstractDownload PDF (1013K) -
Mikio KAJIYAMA, Yoshiyuki OISHI, Masa-aki KAKIMOTO, Yoshio IMAI1992 Volume 49 Issue 3 Pages 235-240
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSStarting from telechelic amine-terminated polydimethylsiloxane (PDMS) oligomers (PDMS-diamines), PDMS-polyimide block copolymers were synthesized by the silylated diamine method. The polymerization of the N-trimethylsilyl-substituted PDMS-diamine, N-trimethylsilylated bis (4-aminophenyl) ether, and pyromellitic dianhydride in diglyme at room temperature afforded the PDMS-polyamic acid trimethylsilyl ester block copolymers. The PDMS-polyimide block copolymer films were obtained by casting the diglyme solutions followed by heating at 300°C. The PDMS-polyimide block copolymers did not decompose below 300°C, and behaved as high temperature resistantelastomers.View full abstractDownload PDF (964K) -
Masaki YOSHII, Hiroki KURAMOTO1992 Volume 49 Issue 3 Pages 241-248
Published: March 25, 1992
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSIn order to analyze the mechanism of the transcription in injection molding, the relationship between the molding conditions and the microscopic flow marks formed on the surface of molded parts of polycarbonate resin has been studied. The results obtained are as follows. (1) When the melt temperature, mold temperature and injecting velocity are low, microscopic flow marks more than 5 nm deep are formed on the surface of the injection-molded parts, and the molding transcription drops. (2) Such flow marks are caused by the cooling of melt resin at the melt front. That is, they are formed in the case that the temperature of the resin near the wall of the mold cooled to the no-flow temperature before that resin contacted the wall of the mold. (3) If those flow marks are eliminated, the molding transcription improves; then the surface roughness of the substrate of 3.2nm in Rmax is nearly equal to that of the stamper of 2.7nm in Rmax.View full abstractDownload PDF (1883K) -
Kazuo MATSUYAMA, Toshiyuki URYU1992 Volume 49 Issue 3 Pages 249-257
Published: March 25, 1992
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBulk polymerization of styrene was carried out at 100°C using initiators of ester group-containing peroxides such as t-butylperoxy benzoate, t-butylperoxy isopropyl carbonate, and t-butylperoxy phenyl carbonate which had approximately equal decomposition temperatures, and analyzed by the kinetic method and the simulation to high conversion. The behavior of the polymerization was influenced significantly by the kind of primary radicals with various reactivities. Particularly, the hydrogen atom abstraction from the polymer by the alkoxy radicals and the primary radical termination by stable phenoxy radicals influenced greatly the rates and the molecular weight of the polymer formed in the latter half stage.View full abstractDownload PDF (1529K)
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