Solid state amorphization and glass transition of tri-O-methyl-β-cyclodextrin
Solid state amorphization and glass transition of tri-O-methyl-β-cyclodextrin
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三-O-甲基-β-环糊精的固态非晶化和玻璃化转变
DOI：
10.1007/bf01913474
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
H. Suga
中科院分区：
文献类型：
--
作者：
I. Tsukushi;O. Yamamuro;H. Suga
通过在室温下用振动磨研磨结晶样品，形成三-O-甲基-β-环糊精的无定形固体。通过X射线粉末衍射技术和差示扫描量热法（DSC）检查非晶化过程。对于研磨25分钟的样品来说，布拉格峰消失并且结晶热变得恒定，表明非晶化明显完成。通过DSC发现研磨的无定形固体的玻璃化转变。通过研磨，玻璃化转变温度 Tg 从 58°C 升至 79°C。研磨样品的饱和Tg与液体淬火玻璃的饱和Tg相同。在 X 射线衍射图谱中未发现研磨的和液体淬火的无定形固体之间存在显着差异。然而，两种无定形固体的红外光谱显示 1194 cm−1 处的谱带存在明显差异，归因于位于分子外围的 CH3 基团的摇摆。
Amorphous solid of tri-O-methyl-β-cyclodextrin was formed by grinding the crystalline sample with a vibrating mill at room temperature. The amorphising process was examined by X-ray powder diffraction technique and differential scanning calorimetry (DSC). The Bragg peaks disappeared and the enthalpy of crystallization became constant for the sample ground for 25 min, indicating the apparent completion of the amorphization. A glass transition of the ground amorphous solid was found by DSC. The glass transition temperature Tgmoved from 58°C to 79°C with grinding. The saturated Tgof the ground sample was the same as that of the liquid-quenched glass. No significant difference between the ground and liquid-quenched amorphous solids was found in the X-ray diffraction patterns. Infrared spectra of both amorphous solids, however, showed a definite difference for the band at 1194 cm−1assigned to the rocking of the CH3groups which are located at the molecular periphery.