Results 271 to 280 of about 192,349 (314)

Time-Temperature Superposition

2016
This chapter consists of three sections: the fundamentals, the geometric interpretation, and the algorithms of time-temperature superposition. The first section deals with the phenomenology, mathematical formulas, models for horizontal shift factor, and molecular explanation of time-temperature superposition.
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Time-temperature superposition for block copolymers

1971
The proposition is made that simple time-temperature superposition should not be valid for block copolymers exhibiting multiple mechanical transitions; and an explanation of the time temperature behavior, which is more consistent with the behavior of the individual phases, is presented in terms of an equivalent mechanical model.
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Time-temperature superposition for partially crystalline polymers (polytetrafluoroethylene)

Polymer Mechanics, 1976
Time-temperature superposition in the\(\mathop \varepsilon \limits^.\) = const regime can be applied to partially crystalline fluoroplastics with different specific volumes. There is a correlation between the variation of the specific volume and the relaxation processes in fluoroplastics.
Yu. F. Dunichev, A. N. Grinman, A. Ya. Gol'dman   +2 more
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Time ? Temperature superposition for thermorheologically complex materials

Polymer Mechanics, 1975
The shift factoraT for thermorheologically complex bodies is a function not only of temperature T but also of the deformation time t. A method is given for determining the vertical shift factor on the basis of macro-tests within the experimental time window.
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Application of principle of time-temperature superposition in studying asphalts

Chemistry and Technology of Fuels and Oils, 1976
1. A method has been developed for application of the WLF principle of time-temperature superposition to describe the viscoelastic characteristics of asphalts. 2. In the example of determining the temperature dependence of undisturbed structure of asphalts, good agreement has been demonstrated between experimental results and values ...
A. A. Akhmetova, B. G. Pechenyi, E. P. Zhelezko   +2 more
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Stress relaxation and time/temperature superposition of polypropylene fibres

Polymer, 1995
The viscoelastic properties of polypropylene fibres are investigated in a single-step stress relaxation test for small strains at temperatures between −50 and + 30 °C, thus well encompassing the glass transition temperature. For the analysis of the curves a formal two-component (TC) model is applied, which comprises an elastic and a viscoelastic ...
K.V. Schulz, F.-J. Wortmann
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Time-temperature superposition in the enthalpy relaxation study of polystyrene

Polymer Engineering & Science, 2016
Enthalpy recovery measurement was used to study the physical aging behavior of a polystyrene. The aging experiments at temperatures (TA) near Tg were conducted with aging times (tA) ranging from several minutes to several days. The recovered enthalpy, ΔH(tA, TA), increased with tA, and then a plateau value of ΔHplate appeared in the long time aging ...
Shiho Kashiwabara, Yutaro Okuya, Yutaka Tanaka   +2 more
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Time-Temperature Superposition in Heterophase Block Copolymers

1973
The viscoelastic behavior of a styrene-butadiene-styrene block copolymer cast from several different solvents was studied in order to examine the validity of the time-temperature superposition principle in heterophase polymers. It is found that stress-relaxation isotherms over a wide temperature range can be easily superposed into smooth master curves.
A. Kaya, M. C. Shen, G. Choi
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Time-temperature superposition in the α region of an epoxy resin

Journal of Macromolecular Science, Part B, 1970
Abstract The relative merits of time-temperature superposition procedures (those of Leaderman, Tobolsky, Ferry, Kě, McCrum, and Morris) have been assessed for the glass-rubber (a) relaxation of an epoxy resin. Measurements of creep compliance in shear were made at temperatures between 24° and 190°C.
G. A. Pogany, N. G. McCrum
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Time-Temperature Superposition in Two-Phase Polyblends

1974
The temperature dependence of the mechanical properties of a 50/50 blend of PVAC and lightly crosslinked PMMA has been examined using the data of Kawai et al. The shift distances, log aT, were generated by bringing the experimental data into coincidence on master curves calculated from a Takayanagi model whose parameters were varied in different ...
D. Kaplan, N. W. Tschoegl
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