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 adia batic 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 k J 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 p oint. This indicates that the entropy fluctuation is different while the gl obal average of the entropy remains the same. We measured the density of th e liquid and supercooled Liquid states for all three samples, and calculate d the amplitude, as well as the amplitude plus wavelength of the entropy fl uctuation.