非等温结晶对PLLA的热行为和形貌的影响(英文)  

Influence of Non-isothermal Melt Crystallization on the Thermal Behavior and Morphology of Poly-L-lactide

作　　者：周智华[1] 阮建明[1] 周忠诚[1] 邹俭鹏[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室

出　　处：《物理化学学报》2007年第5期647-650,共4页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(50174059)资助项目

摘　　要：将聚L-乳酸(PLLA)熔化非等温熔融结晶,采用DSC、POM、SEM等技术研究了降温速率对PLLA的热行为和形貌的影响.PLLA在低降温速率(2℃·min^(-1))下的结晶在118℃伴随有结晶机制的转变.玻璃化温度和结晶度随着降温速率的降低而增大.随着降温速率的降低,球晶尺寸增大,当降温速率为10℃·min^(-1)时,PLLA为无定型材料.采用模压成型的方法并控制降温速率制备了具有球晶结构的条状PLLA生物材料,与高降温速率下制备的PLLA相比,低降温速率下获得的具有球晶结构的PLLA材料的断面更光滑和致密,但脆性增强.The influence of non-isothermal melt crystallization on thermal behavior and morphology of poly-Llactide （PLLA） was investigated by differential scanning calorimetry （DSC）, polarizing micrograph （POM）, and scanning electron microscopy （SEM）. Crystallization performed at lower cooling rate （2 ℃·min^-1） was accompanied by a change of the kinetics around 118 ℃. The glass transition temperature of PLLA decreased with the increase of cooling rate. The crystallinity at the end of crystallization and the size of PLLA spherulites increased with decreasing cooling rate, and PLLA became almost amorphous cooled at a rapid rate of 10 ℃·min^-1. PLLA biodegradable material with spherulites structure was obtained by using compression mould and controlling the cooling rates, and spherulites developed rapidly at lower cooling rates. The fracture surfaces of PLLA at low cooling rates were more compacter and smoother, but more brittle, than those at high cooling rates.

关 键 词：聚-L-乳酸 非等温结晶 热行为 形貌 

分 类 号：O631.3[理学—高分子化学]