Ceiling temperature

{
  "id": "MLC-T-CHM-001771",
  "term": "Ceiling temperature",
  "field": "Chemistry",
  "definition": "The temperature at which polymerization and depolymerization of a monomer balance, so the free-energy change of polymerization is zero and no high-molar-mass polymer forms above it. It equals the enthalpy change divided by the entropy change of polymerization, both negative, and it rises with the monomer concentration. Poly(alpha-methylstyrene) has a bulk ceiling temperature of roughly 60 degrees Celsius, so its polymerization is run at low temperature.",
  "subject": "Polymer",
  "see_also": [
    "floor temperature"
  ],
  "references": [
    "PAC, 2008, 80, 2163. 'Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization (IUPAC Recommendations 2008)' on page 2167 (https://doi.org/10.1351/pac200880102163)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/ceiling-temperature/"
}