Effect of End-Functionalization of Chain Additives on the Microdynamics of Rubber Nanocomposites

In situ X-ray Photon Correlation Spectroscopy (XPCS) can probe the nonequilibrium microdynamical response to dynamic strain of the filler network in a highly filled nanocomposite. We present the microdynamics seen by XPCS for nanocomposites in which lower molecular weight rubber chains are incorporated as polymeric additives. End-functionalizing the chain additives provides a means of modifying the filler-polymer interface to tailor nanocomposite properties. Adding this chain functionalization changes the anisotropy of the response relative to the case in which the short chain additives are not functionalized. The macroscopic properties as measured with Dynamic Mechanical Analysis are considered in light of the insights into the nonequilibrium microdynamics provided by XPCS.



We thank CenTiRe for funding and Dynasol Group for sample preparation. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.