Shift factor

{
  "id": "MLC-T-CHM-010821",
  "term": "Shift factor",
  "field": "Chemistry",
  "definition": "A parameter used in time-temperature superposition to relate the viscoelastic response of a polymer at one temperature to its response at a different reference temperature. It quantifies the extent to which the relaxation times of a polymer are shifted along the logarithmic time or frequency axis due to a change in temperature. The Williams-Landel-Ferry (WLF) equation is commonly used to describe the temperature dependence of this factor for amorphous polymers above their glass transition temperature.",
  "subject": "Polymer",
  "see_also": [
    "Williams-Landel-Ferry equation"
  ],
  "references": [
    "PAC, 2013, 85, 1017. 'Glossary of terms relating to thermal and thermomechanical properties of polymers (IUPAC Recommendations 2013)' on page 1038 (https://doi.org/10.1351/PAC-REC-12-03-02)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/shift-factor/"
}