The ternary system amylose-amylopectin-formic acid as precursor for electrospun fibers with tunable mechanical properties

Abstract

Electrospun starch fibers are promising materials, with potential utility in many fields, including food packaging and tissue engineering. In the present work, we used formylated derivatives of starch constituents, amylose and amylopectin. Various blends of amylose and amylopectin were used to characterize the behavior of starch in formic acid. This approach allowed us to focus on the effect of the polysaccharides ratio on phase behavior, rheological properties and spinnability of solutions and eliminate the effect of molecular characteristics of the polymers. All the tested solutions including pure amylopectin solution proved electrospinnable. All the fibers were largely amorphous and exhibited much higher elongation at break when compared to cast films of the same composition. Amylose-rich fibers demonstrated higher strength, stiffness and ductility, while amylopectin-rich fibers were weak and brittle. This difference in mechanical properties marks possible fields of application of these two types of materials. Fibers with high amylose content may have potential application in food packaging or tissue engineering while fibers with high amylopectin concentration are in favor for control drug release.