Steady state measurements in stress plateau region of entangled polymer solutions: Controlled-rate and controlled-stress modes

Autor:	Sham Ravindranath, Shi-Qing Wang
Rok vydání:	2008
Předmět:	chemistry.chemical_classification Materials science Mechanical Engineering Mechanics Polymer Strain rate Nonlinear flow Condensed Matter Physics Viscoelasticity Physics::Fluid Dynamics Creep Shear (geology) Rheology chemistry Mechanics of Materials General Materials Science Shear flow
Zdroj:	Journal of Rheology. 52:957-980
ISSN:	1520-8516 0148-6055
DOI:	10.1122/1.2936869
Popis:	Despite decades of efforts, reliable measurements of nonlinear flow behavior of well-entangled polymers in continuous shear have been challenging to obtain. The present work attempts to accomplish three important tasks: (A) overcome this challenge by adopting a strategy of decoupling rheological measurements from the outer meniscus region in a cone-partitioned plate (C/PP) setup; (B) determine whether well-entangled solutions indeed undergo a flow transformation under creep that can be taken to phenomenologically define an entanglement-disentanglement transition (EDT); (C) provide the velocity profiles of such solutions undergoing either controlled-stress or controlled-rate shear by carrying out in situ particle-tracking velocimetric (PTV) measurements. Upon removing any influence of edge fracture and sample loss, we are able to reach steady state during continual shear and elucidate more reliably the nonlinear flow behavior of well entangled polymer solutions with little ambiguity. Three well-entangled s...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1ffdcaaeaf5df3b7dd40e43ba3cf212c https://doi.org/10.1122/1.2936869 Zobrazit plný text záznamu