Preparation and characterization of electrospun mats made of PET/chitosan hybrid nanofibers.

In this work we report the preparation and characterization of nanofibrous mats electrospun from mixed solutions of poly(ethylene terephthalate) (PET) and chitosan, with potential applications in such areas as filtration, tissue scaffolds and protective clothing. Polymer compatibility in solution was rather low due to the dissimilarity in the chemical structure of both polymers. We have defined a suitable solvent to both the synthetic, typically hydrophobic polyester, and the biopolymer, and adequate concentrations and molecular weights in order to obtained miscibility of both polymers in solution and suitable electrospinning conditions. The effect of polymer ratio and chitosan molecular weight in the electrospun mat morphology, composition, mechanical and surface properties was evaluated by SEM, ATR-FTIR spectroscopy, and uniaxial tensile tests. The presence of chitosan increased the diameter and the size distribution of the fibers. The effect on the mechanical properties of the nanofibrous mats showed a complex nature dependent on chitosan molecular weight and concentration. Phase separation during solvent evaporation and fiber formation, taking place at varied extent depending on molecular mobility of one of the components, is suggested to explain the formation of hybrid continuous or core-sheath fibers.