Polymer – nanocomposites at rest and under deformation: structure of the nanofillers, conformation of the chains, and related mechanical reinforcement.*

We review work from Laboratory Léon Brillouin and associated groups, on the structure of polymer-nanoparticles composites, under deformation, in relation with mechanical properties improvement of plastics.
First, the nanoparticles: depending on preparation, but also on composition (non grafted or grafted particles), and on the matrix chains molecular weight, they can show individually dispersion, fractal aggregation, compact aggregation (1), or initially anisotropic aggregates. These conditions can be created by physicochemical ways, like solution casting, or combined with an external field, or by industrial protocols like in tyre industry…We will review how to obtain the different cases, and their response to deformation(2). For this we will use first different chemical synthesis, including chain grafting on the particles; second, physical characterization: Small Angle Scattering, mostly from X Rays(SAXS), complemented by Electronic Transmission Microscopy to help us for interpretation of the scattering.
Second, the polymer chains: we will observe them in the matrix (non-crystalline), as well as the grafted ones, combining now X Rays with neutron radiation(SANS), in nanocomposites at rest, and under deformation(3). This leads to striking comparison with measured stress-strain curves.
We will compare and harmonise with results of other groups(4), for a more global view.
(1) C Chevigny, F. Dalmas, E. Di Cola, D. Gigmes, D. Bertin, F. Boué , J. Jestin, Macromolecules 2011, 44 (1)
(2) N. Jouault, F. Dalmas, F. Boué, J. Jestin, Polymer, Polymer 2014, 55, 2523-2534.
(3) N. Jouault, C. Chevigny, F. Dalmas, S. Said, E. Di-Cola, R. Schweins, J. Jestin, F. Boué Physical Review E. 2010 (82) 3
(4) D. Zhao, V. G-Pinto, Andrew M. Jimenez, L. Zhao, J. Jestin, S. K. Kumar, B. Kuei, E. D. Gomez, A.S. Prasa, L .S. Schadler,M. M. Khani, C. Benicewicz, ACS Cent. Sci. 2017 (37) 751.