聚乳酸的静电纺丝行为及其纤维结构研究

Electrospinning of Polylactide and Structures of Its Electrospun Fibers

用静电纺丝法制备了纤维平均直径为350-1900nm的聚乳酸纤维，用扫描电镜研究了纤维的形貌，并用实验设计方法研究了纺丝工艺参数（溶液浓度、电场电压）对纤维平均直径的影响，同时用差示扫描量热分析和X射线衍射研究了静电纺丝所得纤维的结构。研究结果表明：溶液浓度对纤维的平均直径有较大的影响，溶液浓度较低时易形成珠状结构的纤维，纤维的平均直径随着聚合物浓度的增大而增大，并随电场电压的增大而减小。与浇铸膜相比，静电纺丝所制得的纤维有较低的结晶度，并且结晶结构不够完善。由静电纺丝制备的聚乳酸纳米纤维膜在组织工程和药物缓释等领域有潜在的应用前景。

Ultrafine fibers are spun from poly（L-lactide） （PLLA） solution using a homemade electrospinning set-up. Fibers with diameter ranging from 350 nm to 1900 nm are obtained. Morphology of fibers and distribution of fiber diameter are investigated varying concentration and applied voltage by scanning electric microscopy（SEM）. Average fiber diameter and distribution are determined from about 100 measurements of the random fibers with an image analyzer （SemAfore 5. 0, JEOL）. A factorical experiment is designed to investigate and identify the significance of two process parameters （ concentration and applied voltage） on average fiber diameter. It is concluded that the concentration of polymer solution plays an important role in the diameter of fibers. Lower concentration tends to facilitate the formation of bead-on-string structures. Fiber diameter tends to increase with polymer concentration and decrease with applied voltage. Compared with cast film, electrospun fibers has a lower crystallinity and the crystal structure is less perfect. Electrospun PLLA nanofibers have potential usage in tissue engineering, drug delivery, et al.