THERMAL-PROPERTIES AND STABILITY OF GLASSY TRI-O-METHYL-BETA-CYCLODEXTRIN

Glassy tri-O-methyl-beta-cyclodextrin (TMCD) was prepared by cooling t he melt and the glassy state mas confirmed by measuring the glass tran sition temperature (T-g) and the anomalous endothermic peak (heat capa city maximum) on a differential scanning calorimetry (DSC) curve, Glas sy TMCD showed a glass transition at 356 K and an anomalous endothermi c peak. The value of the ratio of T-g and the melting temperature (T-m ) of TMCD was 0.83. The influence of the heating rate of the glass pre pared at the cooling rate of -1.25 K/min on the glass transition was e xamined, and the apparent activation energy of glass transition was ca lculated to be 223.4 kJ/mol, The rate and quantity of relaxation of gl ass was determined by the area under the anomalous endothermic peak of the DSC curves of glasses prepared at various cooling rates, that of glassy TMCD was found to be extremely large. Enthalpy relaxation durin g the isothermal aging of glassy TMCD occurred most remarkably at 341 K, Devitrification of glassy TMCD did not occur for more than 1.5 year s at 25 degrees C. Pulverized glassy TMCD remained as glass for 1 year . Glassy TMCD was very stable and TMCD mas found to be a good glass-fo rmer.