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Volume 42, Issue 11
Displaying 1-5 of 5 articles from this issue
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Dynamic Viscoelasticity of Phenolic-Epoxy Resin SystemsSadao HIRATA, Akira KISHIMOTO1969 Volume 42 Issue 11 Pages 489-493
Published: November 30, 1969
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe dynamic viscoelasticities of unsupported phenolic-epoxy resin films were studied by using the forced vibration technique of longitudinal deformation.
Epikote # 1009 and a resole-type phenolic resin were mixed at the solids weight ratio of 1/1, precondensed, applied on tin plates by a roller coater and baked at 180°and 210°C for 10 min., which were then kept immersed in mercury to obtain film of about 4.8×52.5×0.0455 mm. The angular frequencies employed ranged from 31.4 to 596 sec-1, and the temperatures from 82° to 178°C.
The dynamic Young's moduli, E′ (ω), of all the samples increased with increase in angular frequency, and the maxima of loss tangent, tan δ, appeared at the frequencies and temperatures which corresponded to the inflection points of the E′ (ω) curves. These viscoelastic properties resembled those of thermoplastic materials in the glass transition region.
According to the phenomenological theory of linear viscoelasticity, the curves for the dynamic Young's modulus plotted against the angular frequency and those for the loss tangent plotted against the angular frequency can be shifted along the logarithm of frequency axis to form a composite curve of E′ (ω) and that of tan δ. The shift factors, aT, obtained from the dynamic Young's modulus and the loss tangent agreed with one another for both the systems, which suggested that the time-temperature superposition law was applicable to the phenolic-epoxy systems studied.
The activation energy, ΔH, of the shift factor increased as the temperature was lowered, reaching a maximum at a temperature near the glass transition and then decreasing with further decrease in temperature. The glass transition temperatures, at which each activation energy showed a maximum, were 110°C for the system cured at 180°C, and 123°C for the system cured at 210°C. The glass transition temperature increased with the increase in curing temperature, reflecting the increase in crosslinking density.View full abstractDownload PDF (608K) -
Yasuyuki KUGE, Toshihiko NAKAMICHI, Tsutomu FUJI, Kenji UEKI1969 Volume 42 Issue 11 Pages 494-500
Published: November 30, 1969
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe stress-strain properties of pigmented vehicles were studied by using an Instron tensile testing instrument. VAGH, nitrocellulose/DBP and an oil-modified alkyd resin solutions were pigmented with r-Fe2O3 and rutile titania at the pigment weight concentrations of 10 to 70%. The enamels were sprayed on tin plates, dried at room temperature for 14 days and then at 60°C for 10 hrs. The enamel films 10×100 mm were isolated by dissolving the tin plates in mercury.
With the increase in PVC, the Young's modulus of the film increased, while the elongation to break decreased. The tensile and the strength to break depended on the mechanical properties of the resin, and the plots of the mechanical proper-ties against PVC generally gave maxima, beyond which the Nielsen's theory on the relation between the mechanical properties and the PVC of paint films was fouud to be applicable, that is, the theory was applicable only to the rigid systems. The interaction between the vehicles and γ-Fe2O3 pigment was larger than that between the vehicles and rutile titania.View full abstractDownload PDF (722K) -
Junji SONO1969 Volume 42 Issue 11 Pages 501-505
Published: November 30, 1969
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESS -
Takeo MITSUI1969 Volume 42 Issue 11 Pages 506-515
Published: November 30, 1969
Released on J-STAGE: November 20, 2012
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Decomposition of Polymers and Heat Resistant ResinsHiroshi KAKIUCHI1969 Volume 42 Issue 11 Pages 520-528
Published: November 30, 1969
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (820K)
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