Heat capacities of isomeric 2-butoxyethanols from 13 to 300 K: Fusion and glass transition

We measured the heat capacities of 2-butoxyethanol (abbreviated as nBE), 2-isobutoxyethanol (iBE) and 2-t-butoxyethanol (tBE) from 13 to 300 K by adiabatic calorimetry, and glass transition was found for all three: 140 K (nBE), 146 K (iBE) and 150 K (tBE). We were successful in crystallizing nBE and tBE, and determined thermodynamic functions for Fusion for the first time. The temperatures of fusion and their enthalpy changes are 199.53 K, 11.8 kJ mol(-1) for nBE and 223.09 K, 11.4 kJ mol(-1) for tBE. Where possible, we calculated thermodynamic functions. The total entropy in the liquid state at fusion is almost the same, within 1%, between nBE and tBE. However, the values of the liquid heat capacity are about 10% different at the melting point. This indicates that the entropy fluctuation is different while the global average of the entropy remains the same. We measured the density of the liquid and supercooled Liquid states for all three samples, and calculated the amplitude, as well as the amplitude plus wavelength of the entropy fluctuation.