التفاصيل البيبلوغرافية
| العنوان: |
Dielectric relaxation and elasticity during polymerization. |
| المؤلفون: |
Venkateshan, K., Johari, G. P. |
| المصدر: |
Journal of Chemical Physics; 7/7/2006, Vol. 125 Issue 1, p014907, 7p, 5 Graphs |
| مصطلحات موضوعية: |
MOLECULAR spectroscopy, MOLECULAR dynamics, POLYMERIZATION, DIELECTRIC relaxation, BROWNIAN motion, MOLECULAR structure |
| مستخلص: |
A molecular kinetics-elasticity relation has been investigated by using real time dielectric spectroscopy of a diepoxide-triamine liquid mixture polymerizing at 298 K. As the liquid polymerized, the dielectric relaxation time τ increased linearly with the exponential of the known value of the instantaneous shear modulus G∞, in agreement with the elastic model for viscous flow but without the effect of temperature. Thus the structure-dependent effect on the Brownian motions are separated from the temperature-dependent effect. In this time-dependent process, increase in G∞ may be compensated by an increase in T, thereby keeping G∞ and τ constant. In the potential energy landscape paradigm, a polymerizing liquid’s state point, like a normal liquid’s on cooling, continuously shifts to deeper and lower energy minima of higher curvature, but the shift occurs irreversibly to other parts of the total energy landscape, thus adding a reaction coordinate to the landscape. A minimum in the energy landscape corresponding to a structure formed by polymerization may be identical to a minimum in another landscape corresponding to another structure. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
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