Thermodynamic investigation of glass transition in binary polyalcohols

Abstract The glass transition phenomena of binary systems consist of polyalcohols such as ethylene glycol, propylene glycol, 1,3-propanediol and glycerol were investigated by differential scanning calorimetry (DSC). For every system, composition dependence of the glass transition temperature, T g ( x ), was reproducible with an empirical form, T g ( x )=[ xT g,1 + C g (1− x ) T g,2 ]/[ x + C g (1− x )]. The composition dependence of T g predicted based on the entropy theory for regular solutions agreed well with the experimental results in all systems. Excess configurational entropy, S c E , as deviation from the regular solution model, were very small compared to the expected entropy. The behavior of the present system as a regular solution is discussed from the viewpoint of structural change on mixing.