Nonwoven blend composites based on poly(3-hydroxybutyrate)-chitosan ultrathin fibers prepared via electrospinning.

With the use of scanning electron microscopy, differential scanning calorimetry, and electron paramagnetic resonance, the structural-dynamic analysis of ultrathin fibrous matrixes based on poly(3-hydroxybutyrate) and blend composites of this polymer with chitosan is performed. It is shown that the addition of a small amount of chitosan causes change in the morphologies of the matrixes and leads to a marked increase in their melting enthalpies. It is found that the studied fibers contain amorphous regions with various morphologies. The dynamics of the spin probe TEMPO in these regions is investigated, and its change under the influence of increased temperature, an aqueous medium, and ozone is examined. The mechanism controlling the effects of chitosan, temperature, and an oxidative aggressive medium on the structuring of fibers is advanced. [ABSTRACT FROM AUTHOR]