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Volume 45, Issue 12
Displaying 1-11 of 11 articles from this issue
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[in Japanese]1972 Volume 45 Issue 12 Pages 1033-1041
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSDownload PDF (1224K) -
[in Japanese]1972 Volume 45 Issue 12 Pages 1042-1045
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSDownload PDF (287K) -
[in Japanese]1972 Volume 45 Issue 12 Pages 1046-1055
Published: 1972
Released on J-STAGE: April 16, 2008
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[in Japanese]1972 Volume 45 Issue 12 Pages 1056-1060
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSDownload PDF (381K) -
THERMODYNAMIC STUDY ON THE HETEROGENEOUS STRUCTURE AND FAILURE BEHAVIOR FOR CARBONBLACK FILLED RUBBER VULCANIZATESK. Fujimoto, T. Migita1972 Volume 45 Issue 12 Pages 1061-1068
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSAt first, we assume that carbon black dispersion state in rubber vulcanizates changes from isolated to aggregate at the critical filler quantity, and prove the validity of this hypothesis from the simple calculation for thermodynamic model. Next we make clear that this model is enough to explain the various experimental data qualitatively, for example, the relationships between carbon black quantity and entropic or energetic element of tensile stress, tensile strength and ultimate elongation. In addition, we pressume that this transition occurs at the same apparent volume fraction of fillers containing the dense structure (so-called C-phase) around carbon black particles, and prove this assumption experimentally for several kinds of carbonblack.View full abstractDownload PDF (580K) -
VULCANIZATION OF RUBBER by P-PHENYLENE-3, 3'-DISYDNONEMamoru Hayashi, Shinzo Yamashita, Nariyoshi Kawabata1972 Volume 45 Issue 12 Pages 1069-1073
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSDiene rubbers such as BR, SBR and NBR were found to be easily vulcanized by heating with p-phenylene-3, 3'-disydnone (PDS) at 180°C for 20 to 40 minutes. The PDS vulcanizate was excellent in heat resistance under the condition of oven aging. Tensile strength and elongation at break of the PDS vulcanizate of NBR with carbon black was 217kg/cm2 and 590%, respectively. A mechanism was proposed for this nonsulfur vulcanization, where disydnone dipole forms a pyrazoline ring by 1, 3-dipolar cycloaddition reaction with carbon-carbon double bond of rubber to give the vulcanizate. Sufficient vulcanizate was not obtained from gum stock, because bubbles were produced during the vulcanization due to the generation of carbon dioxide. However, this bubbling was inhibited by the mixing with carbon black or calcium oxide.View full abstractDownload PDF (368K) -
Kumakazu Ohkita, Norio Tubokawa, Haruo Kadoi, Yoshiteru Suneya1972 Volume 45 Issue 12 Pages 1074-1080
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSIn the presence of compunds having the functional groups such as quinone, hydroquinone and aromatic π-bonds on the surface of furnace black, bulk polymerization of vinyl acetate using 2, 2'-azobisiso butyronitrile (AIBN) or benzoyl peroxide (Bz2O2) as an initiator has been studied. The results show that hydroquinone and anthracene in the presence of Bz2O2 act as severe retarders. On the other hand, by the use of AIBN, it is found that p-quinone and anthracene act as mild inhibitors. These phenomena are similar to those of polymerization of monomers in the presence of furnace blacks using an initiator such as AIBN or Bz2O2.
Solution copolymerization of styrene and maleic anhydride has been also investigated in the presence of furnace black using Bz2O2 as an initiator at 30°C. The results indicate that the increases of the rate of agitation hinder polymerization reaction. Thus, it is suggested that the rate of combination of polymer radicals with the active sites formed on carbon black surface by the action of Bz2O2 is greatly accelerated by the agitation.View full abstractDownload PDF (609K) -
GRAFT COPOLYMERIZATION OF N-ACRYLOYL-ω-AMINO ACIDS AND THEIR ETHYL ESTERS ONTO NATURAL RUBBERYasuaki Kozai, Yoshiyuki Ikeda, Harutaka Tomokuni1972 Volume 45 Issue 12 Pages 1081-1088
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSGraft copolymerization of N-acryloyl-β-alanine and N-acryloyl-ε-amino-n-caproic acid onto natural rubber was especially investigated using radical initiators under various conditions. Several physic chemical properties of graft copolymers obtained were also examined.
Graft copolymerization of N-acryloyl-β-alanine: 1) As a polymerization solventamixture of toluene and dioxane with the composition of 2:1 by volume was suitable; 2) BPO and AIBN were effective initiators for graft copolymerization; 3) the higher the concentration of monomer, the better graft results were obtained; 4) the appropriate polymerization temperature was 80 to 100°C; 5) as the degree of grafting increased, the polymer obtained became more easily swollen in water and ethanol but hardly swollen in benzene and carbon tetrachloride.
Graft copolymerization of N-acryloyl-ε-amino-n-caproic acid: 1) Toluene was suitable as a polymerization solvent and BPO was effective as an initiator; 2) the use of 2mol monomer against 1mol rubber produced good results of grafting; 3) the appropriate polymerization temperature was 80°C; 4) the graft copolymer was fairly soluble in benzene or carbon tetrachloride, and the peak of degree of swelling lay at the degree of grafting 80%.
In addition, graft copolymerization of N-acryloyl-γ-amino-n-butyric acid and N-acryloyl-ω-amino acid ethyl esters onto natural rubber was investigated.View full abstractDownload PDF (597K) -
THE ALDOL CONDENSATION REACTION OF ACETONE BY HARD CLAYHitoshi Kawasaki, Katsuhiko Itadani, Fumio Kusano, Soji Kodama1972 Volume 45 Issue 12 Pages 1089-1093
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSHard clay was treated with Soxhlet-apparatus in order to remove the organic impurities. It was found in this process that hard clay catalyzes the aldol-type condensation reaction of acetone. The main product of this condensation reaction was diacetone alcohol. A small amount of mesityl oxide was obtained as by-product.
It has been well known that hard clay is a solid acid, but the results, showed that hard clay can act as a solid base. There was a marked difference in the ability to catalyze the aldol-type condensation reaction of acetone between hard clay and soft clay. Hard clay loaded in SBR showed no catalyzation ability for the aldol-type condensation reaction of acetone.View full abstractDownload PDF (371K) -
THE ACTIVE SITES OF HARD CLAY SURFACE FOR THE INTERACTION BETWEEN SBR AND HARD CLAYHitoshi Kawasaki, Katuhiko Itadani, Fumio Kusano, Soji Kodama1972 Volume 45 Issue 12 Pages 1094-1098
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSIn order to investigate the active sites of hard clay surface which are concerned in the interaction between SBR and hard clay, samples with poisoned active sites on the surface were prepared, and the fluidity and the filler-polymer gel of SBR loaded with these fillers were compared with those of the compounding of calcium carbonate.
With all samples, the activation energy for flow was ca. 10Kcal/mol. The interaction between SBR and fillers which poisoned Brönsted acid sites on hard clay surface was not recognized. But using the fillers with Brönsted acid sites, the interaction between SBR and these fillers was recognized. From these results, it is suggested that the active sites of hard clay surface are Brönsted acid sites.View full abstractDownload PDF (423K) -
ALLYLPHENOLS AS REACTIVE ANTIOXIDANTS FOR RUBBERRyuzo Yamamoto, Masaki Ohara, Tatsuji Sekine, Tatuo Shichimi1972 Volume 45 Issue 12 Pages 1099-1103
Published: 1972
Released on J-STAGE: April 16, 2008
JOURNAL FREE ACCESSIn the previous report, the allylphenol derivatives were found to be effective as reactive antioxidants for rubber because of their profound effects of prevention of oxidative degradation of vulcanizates and their acetone extracted samples.
In this report, it is shown that there are difference in the antioxidative effects between antioxidants which are effective in processing and previously polymerized ones. Under short time cure, it was found that polymerized antioxidants had better ability of antioxidation and anti-extraction with acetone than the others. On the other hand, under longer cure the latter had more powerfull antioxidative effect than the former. It was also shown that, in regard to the reactivities and antioxidative effects of various allylphenols on rubber, triallylphenol cerivatives were superior to di- or mono-allylphenol derivatives.View full abstractDownload PDF (404K)
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