聚丁二酸丁二醇酯的多重熔融行为

Multiple Melting Behavior of Poly(butylene succinate)

采用差示扫描量热仪(DSC)与广角X射线衍射仪(WAXD)研究了等温结晶条件下聚丁二酸丁二醇酯(PBS)样品的多重熔融行为,并对不同熔融峰的起源进行了详细讨论.典型的DSC曲线显示,PBS最多可以呈现4个熔融峰.结果表明:在不同等温结晶条件下所获得的PBS样品晶型均未发生变化,始终保持为PBS的α晶,因此,熔融-再结晶模型可以用来解释PBS的多重熔融现象.峰1、峰2和峰4分别来自于次级晶片、一级晶片以及最稳定晶片的熔融,而峰3则对应着由峰2熔融再结晶所形成的晶片,该晶片与峰4所对应的晶片在形成时存在着动力学上的竞争关系.

The multiple melting behavior of poly （butylene succinate） （PBS）was investigated using differential scanning calorimetry （DSC）and wide-angle x-ray diffraction （WAXD）under isothermal crystallization conditions and the origin of multiple endotherms was discussed in detail. The representative DSC curves showed that PBS had up to four endothermic peaks. WAXD revealed that PBS has the same crystal structure as t^-form over a wide range of crystallization temperatures. A melting and recrystallization model was, therefore, proposed to interpret the multiple melting peaks. Peaks 1,2 and 4 were respectively ascribed to the melting of the secondary, primary and the most stable lamellar crystals. Peak 3, which had a competitive relationship with peak 4 in terms of kinetics, was assigned to the melting of crystallites recrystallized from peak 2.