Speaker
Description
Understanding and predicting the viscoelastic response of polymer melts or concentrated solutions from the knowledge of molecular architecture represents a very active field of research with important challenges. Our first objective is to develop a general coarse-grained model for predicting the viscoelastic properties of linear and branched polymers. Based on the tube theory proposed by de Gennes [1] and by Doi and Edwards [2], as well as on the ability to synthesize well-defined polymers of complex architectures, we have studied more and more complex chain architectures towards randomly branched polymers [3]. This model can now be extended to many other applications [4]. In particular, we investigate the inverse problem of predicting molecular weight distribution from the relaxation moduli, based on a parametric approach, which allows us to face the ill-posedness of this problem. Taking advantage of the high sensitivity of rheology for branched architectures, we also use this approach for the detection of long chain branching. Our present objective is to extend this approach to describe the rheology of macromolecular self-assemblies (such as telechelic polymers) exhibiting reversible structural changes during deformation and thermorheological complexity.
References
[1] M. Doi and S. F. Edwards, The Theory of Polymer Dynamics; Oxford University Press: New York (1986).
[2] P. G. de Gennes, Reptation of a polymer chain in the presence of fixed obstacles, J. Chem. Phys., 55, 572-579 (1971).
[3] E. van Ruymbeke, C. Bailly, R. Keunings, D. Vlassopoulos, A general methodology to predict the linear rheology of branched polymers, Macromol., 39: 6248-6259 (2006).
[4] E. van Ruymbeke, H. Lee, T. Chang, A. Nikopoulou, N. Hadjichristidis, F. Snijkers, D. Vlassopoulos, Molecular rheology of branched polymers: decoding and exploring the role of architectural dispersity through a synergy of anionic synthesis, interaction chromatography, rheometry and modeling, Soft Matter, 10: 27, 4762-4777 (2014).
