聚乳酸/聚环氧乙烷纳米纤维膜的结构与性能表征

采用静电纺丝方法制备了聚乳酸(PLLA)/聚环氧乙烷(PEO)纳米纤维膜，利用扫描电子显微镜(SEM)、差示扫描量热(DSC)、X-射线衍射(XRD)和拉伸测试，对PLLA/PEO纳米纤维膜的形貌、结构、结晶行为和力学性能进行了表征，探究了PEO的质量分数对PLLA/PEO纳米纤维膜的结构、结晶行为和力学性能的影响。结果表明，PEO的加入，降低了PLLA/PEO纳米纤维膜的平均直径和直径分布宽度，提高了纤维的结晶速度、结晶度及断裂伸长率；PEO分子可提高聚乳酸分子链的运动能力和降低纤维的取向度，从而降低因取向引起的中间相含量，提高结晶相含量，进而改善聚乳酸纤维的结晶性能和韧性。

Characterization of the structure and properties of poly (L-lactide)/poly (ethylene oxide) nanofiber membranes

Poly(L-lactide)/poly(ethylene oxide) (PLLA/PEO) nanofiber membranes have been fabricated by an electrospinning technique. The morphology, structure, crystallization behavior and mechanical properties of the PLLA/PEO nanofiber membranes were characterized by field emission scanning electron microscopy (SEM), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and tensile tests. The effects of varying the PEO content on the structure, crystallization behavior and mechanical properties of the PLLA/PEO nanofiber membranes were also investigated. The results showed that the addition of PEO decreased the average diameter and diameter distribution of the PLLA/PEO nanofiber membranes, lowered the glass transition temperature, increased the crystallization rate and crystallinity, and increased the elongation at break. The results suggest that PEO can act as a plasticizer to improve the mobility of PLLA polymer chains and lower the degree of orientation of the nanofibers, and hence lower the content of the mesophase and increase the content of the crystalline phase. Thus the addition of PEO successfully modified the crystallization behavior and toughness of the PLLA nanofibers.