All issues
Predecessor
Volume 61, Issue 8
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
[in Japanese]1988 Volume 61 Issue 8 Pages 535-541
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSDownload PDF (904K) -
[in Japanese]1988 Volume 61 Issue 8 Pages 542-548
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSDownload PDF (1054K) -
[in Japanese]1988 Volume 61 Issue 8 Pages 549-557
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSDownload PDF (1323K) -
[in Japanese]1988 Volume 61 Issue 8 Pages 558-560
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSDownload PDF (512K) -
EFFECTS OF CARBON BLACK FILLERSKenzo FUKUMORI, Norio SATO, Toshio KURAUCHI1988 Volume 61 Issue 8 Pages 561-567
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSMotional heterogeneity of the network chains in nitrile rubber (NBR) vulcanizates was studied by the measurement of the spin-spin relaxation time, T2, in stretched states, and was related to the stress relaxation properties at constant strains. The T2 signal for NBR can be resolved into two components (short T2 and long T2). The short T2 component is considered to be assigned to the regions of the network chains in the vicinity of the crosslinks, closely connected with the deformation behaviors of the network chains. The fraction of the short T2 component increases with stretching, reflecting the enlargement of the motionally constrained regions. With the increase of the carbon black filler concentration, the increase of its fraction is rather suppressed, which is associated with the energy dissipation in the rubber matrix caused by various kinds of stress relaxation mechanisms through the rubber-filler interactions. It has become clear that strain amplification in filled systems is a usefull concept in the experimental correlations between the macroscopic strain and the molecular mobility of the network chains.View full abstractDownload PDF (878K) -
Kenkichi MURAKAMI, Kyung-Do SUH, Hidetoshi OIKAWA1988 Volume 61 Issue 8 Pages 568-578
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSThe relation between the properties and structure of rubber vulcanizates with less entanglements (approximate phantom network) and those with normal curing was studied by the X-ray diffraction method, a stress-stress curve, a birefrigence, and Mooney-Rivlin plot etc.
It is known that the parameter h which is the parameter of fluctuation of crosslink sites is unity for a typically phantom network rubber. For the sample which is a rubber vulcanizate with normal cure prepared by us, h is approximately a half. This indicates that the degree of flutuation of the crosslink sites is approximately medium between Affine deformation and phantom deformation for our samples.View full abstractDownload PDF (1212K) -
Iwao YAMASHITA, Noboru YAMAMOTO, Kazuko HAYASHI1988 Volume 61 Issue 8 Pages 579-585
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSIt has been previously reported that a series of segmented polyetherurethaneureas (DPs) prepared from hydroxy terminated triblock copolyether (BPE, PEO-PPO-PEO), 4, 4′-diphenylmethane diisocyanate (MDI) and ethylene diamine (E) exhibited an excellen antithrombogenicity and a long-term durability. In this study, the effect of the composition of soft and hard segments (SS & HS) on the tensile properties of 22 different DPs was discussed from the stress-strain data plotted according to the Mooney-Rivlin equation. No significant differences of the value of C1 terms were found by change in the content of HS, when the same BPE was used. And the C2 values were approximately proportional to the content of HS. The C2/C1 values were higher than those for vulcanized rubbers. Generally, the glass transition temperature (T2) of SS in polymer reflects the extent of microphase separation of soft and hard domains. On the series of DPs having the same content of HS and the different chain lengths of SS, the values of C2 term increased with an increase in the Tg of SS, but the values of C1 term were almost independent of the Tg of SS. This may imply that the variation of phase separation affects mainly the value of C2. The antithrombogenicity of DPs was also discussed from a viewpoint of their microphase separation and their hydrophilicity.View full abstractDownload PDF (795K) -
Keizo MAKUUCHI, Kyogo THUSHIMA1988 Volume 61 Issue 8 Pages 586-591
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL FREE ACCESSA study was made to clarify the features of the radiation vulcanization (RV) of natural rubber latex sensitized by acrylates (RV-A). The vulcanization rate of RV-A is higher compared with that of RV sensitized by carbon tetrachloride (RV-C). There are no difference in mechanical properties between RV-A and RV-C films. Tensile strength (TB) of RV-A films increase after air-aging at 100°C for 48 hours. On the contrary, TB of RV-C films and films prepared from conventional sulfur vulcanization method (V-S) decrease to half of the original ones at the same aging conditions. Leaching of the films with water affects aging properties of RV films. Leached RV-A and RV-C films lose almost original TB after air-aging at 70°C for 100 hours. While, V-S films shows fair resistance. When the aging is carried out at 150°C in the absence of air, leached RV films show higher resistance than leached and un-leached V-S films. It was concluded that RV-A films inherently have resistance against oxidative aging, but leaching reduces the resitance remarkably.View full abstractDownload PDF (696K) -
[in Japanese]1988 Volume 61 Issue 8 Pages 592-593
Published: 1988
Released on J-STAGE: July 09, 2007
JOURNAL RESTRICTED ACCESSDownload PDF (238K)
- |<
- <
- 1
- >
- >|