Microscopic Chain Motion in Polymer Nanocomposites with Dynamically Asymmetric Interphases
Erkan Senses, Antonio Faraone, Pinar Akcora
Dynamics of the interphase region between matrix and bound polymers on nanoparticles is important to understand the macroscopic properties of nanocomposites. Here, we present neutron scattering investigations on nanocomposites with dynamically asymmetric interphases formed by a high-Tg bound polymer, poly(methyl methacrylate), on nanoparticles and a low-Tg miscible matrix, poly(ethylene oxide). By taking advantage of selective isotope labeling of the chains, we studied the role of interfacial polymer on segmental and collective dynamics of the matrix chains from sub-ns to 100 ns. Our results show that the Rouse relaxation remains unchanged in weakly attractive composite systems while the dynamics significantly slows down in case of strong attraction. More importantly, the chains disentangle with a remarkable increase of the reputation tube size when the bound polymer is vitreous. The glassy and rubbery states of the bound polymer as temperature changes underpin the macroscopic stiffening of the nanocomposites.
, Faraone, A.
and Akcora, P.
Microscopic Chain Motion in Polymer Nanocomposites with Dynamically Asymmetric Interphases, Scientific Reports, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=920513
(Accessed December 6, 2023)