Effect of the Addition of Iron(III) Tetraphenylporphyrin Complex on the Structure of Poly(3-hydroxybutyrate) Fibers Prepared by Electrospinning

Ultrathin fibers of poly(3-hydroxybutyrate) biopolymer, containing 1–5 wt % iron(III) tetraphenylporphyrin complex, were prepared by electrospinning. The intermolecular interaction of fiber components was studied by UV spectroscopy. Paramagnetic reaction sites in the mixtures were revealed by magnetic resonance. The structure of crystalline and amorphous domains of the fibers was studied by differential scanning calorimetry, X-ray diffraction analysis, spin-probe ESR, and scanning electron microscopy. Introduction of the complex into poly (3-hydroxybutyrate) fibers leads to an increase in the crystallite size and to a considerable increase in the degree of crystallinity; the molecular mobility in the amorphous domains of the polymers decreases. Thermal annealing at 140°C leads to a sharp increase in the crystallinity and to a decrease in the molecular mobility in amorphous domains of poly(3-hydroxybutyrate). Ozonolysis of the fibers at a short treatment time (up to 5 h) causes sharp deceleration of the molecular mobility; at longer ozonation of the fibers, the mobility increases. The fibrous materials obtained exhibit bactericidal properties and can be used for developing antibacterial and antitumor therapeutic systems.