Thermodynamics of polymerization of heterocyclic compounds I—The heat capacity, entropy and enthalpy of trioxan

Abstract

An adiabatic, vacuum calorimeter has been used to measure the heat capacity of trioxan from 80°K to 310°K. An approximate extrapolation procedure has been used to estimate heat capacities below 80°K. Entropy and enthalpy values have been derived and are listed at ten degree intervals. Published vapour pressure data have been used to calculate the entropy of trioxan gas at one atmosphere pressure and 298.16°K. The value obtained 68·09±0·82 cal deg −1 mole −1 compares with that of 68·99±0·01 cal deg −1 mole −1 obtained by statistical methods. The entropy of polymerization of trioxan to crystalline polyoxymethylene, ΔS 0 gc′, has been calculated as −37·2 cal deg −1 mole −1.