g-factor

{
  "id": "MLC-T-CHM-004869",
  "term": "g-factor",
  "field": "Chemistry",
  "definitions": [
    "A dimensionless ratio that compares the coil size of a branched molecule, measured by its mean-square radius of gyration, with the same quantity for a linear molecule of equal molar mass. A value below 1 shows that branching is present, and the lower the value, the more compact the macromolecule. Linear chains have a value of exactly 1 by definition.",
    "A dimensionless branching parameter formed by dividing the intrinsic viscosity of a branched polymer by that of a linear polymer with the same molar mass, measured in the same solvent at one temperature. A value below 1 signals long-chain branching, because branched coils are more compact and raise viscosity less. It is distinct from the g-factor, which compares mean-square radii of gyration instead of viscosities."
  ],
  "synonyms": [
    "contraction factor",
    "geometric contraction factor",
    "radius of gyration contraction factor",
    "hydrodynamic contraction factor",
    "viscosity contraction factor"
  ],
  "subject": "Polymer",
  "see_also": [
    "g′-factor",
    "mean-square radius of gyration",
    "g-factor"
  ],
  "references": [
    "PAC, 2015, 87, 71. 'Definitions of terms relating to individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers (IUPAC Recommendations 2014)' on page 81 (https://doi.org/10.1515/pac-2013-0201)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/g-factor/"
}