In this letter, both the viscoelastic and electrical properties of poly(methyl methacrylate)/carbon black (PMMA/CB) nanocomposites with different CB concentrations prior to and after annealing were investigated. The linear steady-state recoverable compliance of pure PMMA is independent of annealing as it reflects only polymer-polymer interactions. While the conductivity of PMMA/CB nanocomposites increases gradually with annealing, and the viscoelastic properties show different regions of response depending on the CB concentration. At CB contents below the percolation threshold the recoverable compliances increase after annealing, whereas the reverse trend is found at CB contents above the percolation threshold. This behavior is related to the interplay between network formation and particle particle interactions. (C) 2017 Elsevier Ltd. All rights reserved.