All issues
Predecessor
Volume 55, Issue 3
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Toshio INOUE1998 Volume 55 Issue 3 Pages 103-118
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNovel dynamic crosslinking reaction with the N, N″-m-phenylene-bis-maleimide/dihydroquinoline derivative system was carried out on various PP/EPDM blends, and its effect on Izod impact strength (IIS) was investigated. The system crosslinked EPDM domains selectively and did not degrade PP matrices virtually. The IIS increased on crosslinking. During the reaction, PP/EPDM graft-copolymers were produced at the PP-EPDM interfaces to strengthen the interfacial adhesion. The resultant high interfacial adhesion sustained de-bonding at the interfaces under stress and permitted to develop stress concentration zones into PP matrices effectively. When the developed concentration zones were close enough to interact, shear yielding increased the IIS's dramatically. The dynamic crosslinking thus caused a dramatic increase of the IIS's of PP/EPDM blends not only at a low EPDM wt% but also at a low temperature. The crosslinked EPDM domains acted as nucleating agents and affected the characters of the crystalline structure and tie molecules. These effects may also increase the IIS.View full abstractDownload PDF (6750K) -
Masafumi YAMATO, Fusako KIYONO, Tsunehisa KIMURA, Eiko ITO1998 Volume 55 Issue 3 Pages 119-124
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe structure change of the melt-quenched poly (butylene terephthalate) on annealing below the glass transition temperature (Tg) was studied by means of infrared (IR) spectroscopy and the dielectric relaxation measurements. The IR spectra obtained for the sample annealed below Tg were different from that of the quenched sample. The comparison of these spectra with the spectrum obtained for a highly crystallized sample indicated that the below-Tg annealing caused some structures similar to the crystalline structure. These observations by IR spectroscopy were in accordance with the results of the dielectric measurements. The dielectric strength of the β dispersion was decreased on annealing. This was ascribed to the reduction in the chain mobility contributing to the β dispersion due to the change in packing of aromatic rings. The change in packing was also reflected in the shift of the maximum peak position of the β dispersion toward lower frequencies.View full abstractDownload PDF (1126K) -
Masafumi YAMATO, Ritsuko MUROHASHI, Tsunehisa KIMURA, Eiko ITO1998 Volume 55 Issue 3 Pages 125-129
Published: March 25, 1998
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSThe structure change on annealing of poly (ethylene-1, 2-diphenoxyethane-p, p′-dicarboxylate) (PEBC) was studied by high-resolution solid-state 13C NMR spectroscopy. The resonance peak assigned to the aromatic carbons at 3-and 5-positions changed from a single peak to a doublet on annealing of a quenched sample. This is a reflection of the change in molecular mobility associated with the structure change. The NMR line shape for aromatic carbons at 3-and 5-positions was simulated under the assumption that the mechanism of motion is π-flip around the C1C4 axis. The result of simulations suggested that the rate of the π-flip is about 800 Hz in the quenched sample and between 200 Hz and 800 Hz in the annealed samples. It was suggested that the packing of molecular chains in amorphous region is higher for the sample annealed at higher temperatures.View full abstractDownload PDF (852K) -
Masaaki KONDO, Satoru AIKAWA, Shigeru TASAKA, Norihiro INAGAKI1998 Volume 55 Issue 3 Pages 130-136
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAutoxidized methyl linoleate was used as the initiator of radical polymerization of styrene and the influence of the oxidation levels on the structure of resulting polymers was investigated. Autoxidized methyl linoleate contained mainly monomers and oligomers with hydroperoxide moieties. They are able to work not only as an initiator but also as a crosslinking agent for the polymerization of styrene. The polymers synthesized by the oxidized products were not gelled and soluble in polar solvents completely. Therefore, the polymer was assumed to consist of linear (non-closslinked) chains having autoxidized methyl linoleate.View full abstractDownload PDF (1163K) -
Koji MINAMITANI, Takehiko GOTOH, Shuji SAKOHARA1998 Volume 55 Issue 3 Pages 137-144
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPorous polymers with crystalline structure of hydrophobic long alkyl side chains were prepared by drying the gels synthesized by copolymerizing stearyl acrylate (SA) or stearyl methacrylate (SMA) with ethylene glycol dimethacrylate (EGDMA) as the cross-linker. With dimethylformamide as a solvent and at selected concentrations of a primary monomer (SA or SMA) and EGDMA, gels consisted of micro polymer particles and solvent phases which were formed by the phase separation in the polymerization process were obtained. Furthermore, it was confirmed by DSC measurements that the hydrophobic long side chains of SA or SMA in the gels were crystallized. The porous polymers with low bulk densities were obtained by drying the gels below the melting temperature of the crystalline structure of long side chains of SA or SMA. On the other hand, the drying temperature above the melting temperature formed shrunk polymers with high bulk densities. These phenomena suggest that the porous structure or the bulk density of dried polymer can be controlled easily by the drying temperature.View full abstractDownload PDF (6979K) -
Yasukatsu MAEDA, Atsuyoshi NAKAYAMA, Terufumi TAKEUCHI, Mitsuya OGAWA, ...1998 Volume 55 Issue 3 Pages 145-151
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDegradation behaviors of chain-extended copoly [succinic anhydride (SA) /ethylene oxide (EO)] were investigated by biodegradation tests in soil or in sea. The weight loss of copolymer samples in soil were more than one in sea. In summer season, degradation was accelerated compared to that in winter season. The results of observation by optical microscopy showed the degradation process of copoly (SA/EO) s in soil or in sea proceeded as follows: (1) the cracks occurred on the polymer surface, (2) the degradation spread out in the crack, (3) the crack became progressively wider. The increase of SA content in polymer composition depressed the rate of the degradation in soil or in sea. These results agreed with those obtained by the enzymatic hydrolysis and by the degradation test using activated sludge.View full abstractDownload PDF (5675K) -
Yukihiko INOUE, Noritaka OHTANI, Yukie YANO, Mihoko SATO, Yasuhiro NAG ...1998 Volume 55 Issue 3 Pages 152-155
Published: March 25, 1998
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSTrimethylammonium group-attached polyacrylamide gel was synthesized from acrylamide (AAm) and N- (3- (trimethylammonio) propyl) acrylamide chloride salt (TMAPAAC), and its swelling behavior in aqueous surfactant solutions was investigated. In SDS (sodium dodecylsulfate) solution, the gel exhibited a drastic volume decrease at around 10-4mol dm-3 and gave a minimum volume at 8×10-4mol dm-3. In more concentrated solution, however, the gel exhibited an increase in volume. This behavior was caused probably by the different interactions of the surfactant molecules with the polymer-attached cationic groups and the hydorophobic polymer chain.View full abstractDownload PDF (792K)
- |<
- <
- 1
- >
- >|