Ceiling Temperature Calculator

Understanding Ceiling Temperature

The ceiling temperature (Tc) is the critical thermal point at which a polymer is equally likely to polymerize and depolymerize. This fundamental concept in polymer chemistry helps determine the conditions under which polymerization reactions can successfully occur.

Formula

$$T_c = \frac{\Delta H_\text{polymerization}}{\Delta S_\text{polymerization}}$$

Where:

• Tc = Ceiling temperature (K)
• ΔH = Change in enthalpy (J/mol)
• ΔS = Change in entropy (J/(mol·K))

Example Calculation

For a polymerization reaction with:

• ΔH = 40 kJ/mol
• ΔS = 25 J/(mol·K)

First, convert ΔH to J/mol:

• ΔH = 40 kJ/mol × 1000 = 40{,}000 J/mol

Then calculate:

• Tc = 40{,}000 J/mol ÷ 25 J/(mol·K) = 1{,}600 K

This means the ceiling temperature for this polymer is 1{,}600 K. Above this temperature, the polymer will depolymerize rather than continue to polymerize.