Time-temperature-concentration superposition principle is disclosed to linear dynamic rheology of carbon black (CB) filled high-density polyethylene (HDPE) with a wide range of CB volume fraction. The time-concentration superposition (TCS) principle is also validated in CB filled ethylene-tetrafluoroethylene (ETFE) alternating copolymer at 260 degrees C. The frequency-dependent viscoelastic functions can be superposed onto universal master curves with the reference of the unfilled HDPE and ETFE. The filler network and strain amplification concepts are used for accounting for the TCS principle. (C) 2009 The Society of Rheology. [DOI: 10.1122/1.3216923]