Long time stress relaxation of amorphous networks under uniaxial tension: The Dynamic Constrained Junction Model

Konyalı, Haluk and Menceloğlu, Yusuf Z. and Erman, Burak (2008) Long time stress relaxation of amorphous networks under uniaxial tension: The Dynamic Constrained Junction Model. Polymer, 49 (4). pp. 1056-1065. ISSN 0032-3861

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Abstract

Poly-isoprene networks with different degrees of cross-linking and filler amount are studied under uniaxial stress relaxation. Time decay of stress obeys a stretched exponential form with a stretching parameter of 0.4 that is same for all independent variables, i.e., extensions, crosslink density and filler amount. Relaxation time τ increases with increasing strain, and decreases with both cross-link and filler content. Dependence of τ on filler content is less sensitive than on cross-link density. The isochronous Mooney-Rivlin plots show that the phenomenological constant 2C1 is time independent, and all time dependence results from that of 2C2 , which is associated with relaxation of intermolecular interactions at and above the length-scales of network chain dimensions. The relatively low value of the stretching parameter is interpreted in terms of a molecular model where entanglements contribute to relaxation at a wide spectrum of time scales.
Item Type: Article
Uncontrolled Keywords: Entanglements, junction fluctuations, viscoelasticity.
Subjects: T Technology > TP Chemical technology > TP1080 Polymers and polymer manufacture
Divisions: Faculty of Engineering and Natural Sciences > Academic programs > Materials Science & Eng.
Depositing User: Yusuf Z. Menceloğlu
Date Deposited: 30 Oct 2008 16:49
Last Modified: 26 Apr 2022 08:21
URI: https://research.sabanciuniv.edu/id/eprint/9629

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