Thermodynamic functions of linear high polymersPart I—polyoxymethylene

An adiabatic, vacuum calorimeter has been used to determine the heat capacity of two samples of polyoxymethylene (prepared by different routes) in the temperature range 20° to 300°K. Entropy and enthalpy values have been derived for the two polymers and are listed at ten degree intervals. The entropy of polymerization, ΔS0gc has been calculated as −41.8±0.2 cal. deg.−1 per CH2O unit whereas that obtained from equilibrium pressure measurements of gaseous formaldehyde over solid polyoxymethylene is −30.7 cal. deg.−1 per CH2O unit. Possible reasons for this discrepancy are examined and suggestions are made for further work to resolve it.