Conventional polymer fibers are manufactured by mechanical extrusion and a secondary post-drawing step that stretches the fiber to several times its original length to induce molecular alignment and impart strength. Unfortunately, nanofiber materials are not compatible with conventional post-drawing processes because of their small size and delicate mechanical properties. As a result, electrospun nanofibers are mechanically weaker than their conventional microfiber counterparts, contrary to the theoretical expectation of increased strength with decreasing fiber diameter. We have developed new methods to post-draw thousands of individual electrospun nanofibers within a continuous manufacturing/processing system (<b>Fig. 1</b>). This will allow an unprecedented ability to systematically examine the mechanisms associated with nanofiber post-drawing. Polymer nanofiber macromolecular arrangement, crystallinity, crystalline alignment and mechanical strength are assessed with FTIR, DSC, X-ray, and mechanical analysis (<b>Fig. 2</b>). The effect of drawing conditions on these properties are analyzed and mechanisms are proposed.

Effect of post-drawing on the macromolecular and functional properties of polymer nanofibers

251st National Meeting (2016)

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