Professor, Joseph Fourier University of Grenoble
Visiting Professor, Flinders University of South Australia
Friday, November 19, Noon to 1 PM, Room 106, Rogers Bldg
"Linear and nonlinear thermo-viscoelasticity of bio-degradable polymers: applications to poly(lactic) acids (PLA)"
Summary:
The vast majority of existing polymer materials - including the widely used polystyrene and poly(vinyl chloride) - are, on one hand, made from noxious or toxic monomers, and, on the other hand, are based on nonrenewable fossil resources, which will eventually be extinguished. Hence there is an increasing interest in using new, environmental friendly, synthetic macromolecules based on renewable resources. In this talk, the thermo-viscoelastic behavior of high L-content poly(lactic) acids (PLA) is investigated. Measurements of dynamic, steady, and transient shear viscosities are presented. Extensional data on PLA are presented for the first time and show a strong strain hardening behavior. The Cox-Merz relationship is obeyed over a particularly wide range (roughly 3 decades of shear rate). The transient shear results are satisfactorily predicted using a truncated form of the K-BKZ constitutive equation and a set of Maxwell modes derived from the dynamic spectra. However, it is shown that, in order to capture the observed extensional hardening, this constitutive law must be adequately modified.
Biographical notes:
Education:
2003: Habilitation, Joseph Fourier University of Grenoble.
1996: PhD, Joseph Fourier University of Grenoble: research work done in polymer
rheology; recipient of the 1996 French Society of Rheology annual award for
the PhD work.
1992: MS degree in mechanics.
1991: BS degree in fluid mechanics, National Polytechnic Institute of Grenoble
(INPG), France.
1988: BS degree in thermo-mechanical engineering, University of Galati, Romania
(a five year engineering program).
Academic experience:
Currently: Associate Professor of Engineering and Applied Mathematics, National Institute of Applied Sciences (INSA) of Lyon, France.
2004: Visiting Professor, Flinders University of South Australia.
2001: Visitor, Texas A&M University.
1998-2001: Research Assistant Professor, Colorado School of Mines.