Heat Capacity of Poly(vinylmethylether) in the Presence and Absence of Water

Heat capacity, $C_{p}$, of poly(vinylmethylether), PVME, without and with water has been measured from 5-375 K, using adiabatic and differential scanning calorimetry. The PVME has a glass transition at 248 K. At lower temperatures, $C_{p}$ of the solid is linked to group and skeletal vibrations. The skeletal vibrations are described by a Tarasov equation with three characteristic temperatures. The experimental $C_{p}$ agrees to better than $\pm $3{\%}. The $C_{p}$ of the liquid is 72.36 + 0.136~$T$ [J/(K mol)] and compares well with results estimated from constituent groups of other polymers using the ATHAS Data Bank. The calculated solid and liquid $C_{p}$ was used as baseline for the analysis of amorphous PVME with different thermal history, to follow the crystallization, melting, mixing, and demixing within the PVME-water system. Also, knowing $C_{p}$ of the solid and liquid, the enthalpy, entropy, and Gibbs function of glassy and liquid PVME was calculated..