Thermal behavior of trehalose dihydrate (T h) and β-anhydrous trehalose (T β) by in-situ laboratory parallel-beam X-ray powder diffraction

Thermal behaviors of trehalose dihydrate (T (h)) and beta-anhydrous trehalose (T (beta)) have been investigated by in-situ laboratory parallel-beam X-ray powder diffraction. Data indicate that both phases show essentially the same volume expansion but expansion of the anhydrous form is markedly anisotropic due to the features of the hydrogen-bond network. Under the present experimental conditions, dehydration starts at 66 A degrees C and within the 75 < T < 114 A degrees C the presence of the T (alpha) anhydrous polymorphic form has been detected.