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Volume 40, Issue 6
Displaying 1-8 of 8 articles from this issue
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PART IV. A MODIFICATION OF THE THEORY OF LINEAR VISCOELASTICITY FOR INTERPRETING SOME NON-LINEAR MECHANICAL PROPERTIES OF POLYMERSK. Ninomiya, G. Yasuda1967 Volume 40 Issue 6 Pages 458-462
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSIn a polymeric system being deformed at a constant rate of strain, the stress shared by the relaxation mechanisms whose viscous elements are being deformed at a rate of strain practically the same as that of the total system may be called the viscous stress. Meanwhile the elastic stress can similarly be defined, and thus the total stress may be approximated as an arithmetic sum of those two stresses. This approximation is then substantiated on the theory of linear viscoelasticity by introducing a parameter called the critical relaxation time θc which divides the whole relaxation spectrum into two parts.
The rupture phenomenon was taken into account for the elastically behaving mechanisms and the following approximate relationship was obtained for the shear rate dependence of the steady-flow viscosity,
ηapp·ηapp≅∫lnθc-∞θHd (ln θ), θc=γb/γ0, where H, θ and γ0 are the relaxation spectrum, the relaxation time and the rate of strain, respectively. The quantity γb′ stands for the strain at break. Hence we obtain
η′ (ω) ≅ηapp (γ) |γ=γbω
where η′ (ω) and ω represent the dynamic viscosity and the angular frequency, respectively.View full abstractDownload PDF (1434K) -
PART II APPLICATION OF THE NEW METHOD TO THE MECHANICAL DATA ON PARTIALLY CRYSTALLINE POLYMERSI. Furuta, M. Nakao, E. Maekawa1967 Volume 40 Issue 6 Pages 463-466
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDynamic mechanical properties of several samples of polybutadiene (raw, cross-linked, filled, etc.) which are known to be partially crystalline polymers at low temperatures, were measured over a frequency range from 1 to 70 c.p.s. at temperatures from-74° to 0°C by a viscoelastic spectrometer. Application of the recent blending law, which had been proposed in the preceding paper, to the experimental data was found quite successful.View full abstractDownload PDF (456K) -
HETEROGENEOUS REACTIONS BETWEEN ZINC OXIDE AND 2-MERCAPTOBEN-ZOTHIAZOLE (M)H. Shizuka, T. Azami1967 Volume 40 Issue 6 Pages 467-471
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSHeterogeneous reactions between ZnO and M were studied, by means of tracer method (S35 or Zn65), in xylene and in rubber, respectively. Zinc mercaptobenzothiazole (MZ) was produced by these reactions. Heterogeneous reactions in xylene were observed as zero order and their rates had a nearly constant value at every temperature (120, 130 and 138°C). The rate-determining step does not consist in the reaction process, but in the dispersing process of the product (MZ) from ZnO surface.
The effect of addition of small amounts of ZnO or MZ on the exchange reaction between M and S* was investigated. The reaction rate was remarkably increased. The exchange reaction between MZ and S*, in xylene heterogeneous system, reached quickly the exchange equilibrium. MZ and radioactive M were easily exchanged. The curing of rubber gave a large quantity of MZ (yield, 73%). The results of these re-actions can be represented by the following schemes (1), (2), (3) and (4).
2M+ZnO→MZ+H2O (1)
MZ+S8*ring→k2M*Z+·Sn*·(2)
M*Z+M→MZ+M* (3)
M+S8*ring→k4M*+·Sn*· (4)
k2>k4
From these studies, it is concluded that the reaction product (MZ) promotes the ring opening action of elementary sulfur (S8 ring structure) and active sulfer (· Sn ·) enables the curing of rubber.View full abstractDownload PDF (814K) -
PART VIII A PHENOMENOLOGICAL INTERPRETATION OF THE DEFORMATION AND FLOW OF RAW RUBBER IN A MOONEY VISCOMETERG. Yasuda, M. Takashima, K. Ninomiya1967 Volume 40 Issue 6 Pages 472-484
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSThe recently developed approximation of the theory of linear viscoelasticity involving the concept of the critical relaxation time, the information on the macroscopic flow unit which has been found and called the rheological unit by Mooney, and recent investigation on the non-linearity of the elasticity of raw rubbers are all put together to interpret quantitatively the deformation and flow behavior of raw rubbers in a Mooney viscometer. Then the empirical equations describing the time dependence of the shear stress in raw rubbers while rotating the rotor and also the stress relaxation behavior after sudden cessation of the rotation of the rotor, which were found several years ago, seemed to permit some phenomenological interpretations And thus the six time-independent parameters involved in those equations were correlated respectively with other viscoelastic quantities which could be measured separately. For instance, for the torque at the steady-flow state, (XL+YL), we have
XL≅ (1/ks)γsG′(ω) |ω=γ0
YL≅ (1/ks)γ0η′(ω)|ω=γ0
Here ks is a conversion factor between torque and shear stress; and γs and t s are the elastic strain at the steady-flow state and the rate of shear (constant), respectively; G′(ω) and η′(ω) are the real parts of the complex rigidity and viscosity, respectively; and ω is the angular frequency.
Experimental data obtained under various conditions both in material and exitation checked fairly well those relations.View full abstractDownload PDF (1936K) -
1967 Volume 40 Issue 6 Pages 484
Published: 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (110K) -
[in Japanese]1967 Volume 40 Issue 6 Pages 485-489
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (953K) -
[in Japanese]1967 Volume 40 Issue 6 Pages 490-504
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (2737K) -
1967 Volume 40 Issue 6 Pages 509-510
Published: June 15, 1967
Released on J-STAGE: October 16, 2009
JOURNAL RESTRICTED ACCESSDownload PDF (402K)
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