| In this research, temperature Modulated Differential Scanning Calorimetry (MDSC) is used to measure the heat capacities of unary and binary solid solutions of Organic "Plastic Crystal" Thermal Energy Storage (TES) Materials. The first part of the results includes heat capacities of three pure organic "plastic crystal" compounds; neopentylglycol [NPG:(CH3)2-C-(CH 2OH)2), 2-amino-2-methyl-1,3-propanediol [AMPL:(NH2 )(CH3)-C-(CH2OH)2], and tris(hydoxymethyl)-aminomethane [TRIS:(NH2)-C-(CH2OH)3] in their low temperature ordered alpha-phase, high temperature orientationally disordered gamma-phase as well as liquid phase. The second part of the results presents the solution heat capacities of NPG-TRIS binary system and the calculated excess heat capacities of the high temperature "plastic" and liquid phases. A discussion on the compositional as well as temperature dependency of excess heat capacities in liquid and high temperature solid "Plastic" Phase is presented. The knowledge of excess heat capacities is shown to be of significance for the thermodynamic modeling and phase diagram calculations of these organic "Plastic Crystal" binary systems. |
