Hydrolytic Degradation and Morphological Characterization of Electrospun Poly(glycolic acid) [PGA] Thin Films of Different Molecular Weights Containing TiO2 Nanoparticles

Thin films of polyglycolic acid (PGA), a biodegradable and biocompatible polymer, were prepared by electrospinning and were studied according to their molecular weights. TiO 2 nanoparticles were also used as additives at concentrations of 2–8 wt%. The films were morphologically characterized and exhibited a homogeneous distribution of TiO 2 with only slight differences depending on the molecular weight. In particular, fibers with low-molecular-weight PGA were thinner and had an average diameter of 77 nm. Furthermore, they showed a higher resolution of the TiO 2 crystal planes regardless of the crystal habit involved. During the melting of the PGA fibers, one single and prominent melting endotherm was observed, which was independent of molecular weight, TiO 2 content, and crystal phase involved. This was in contrast to quiescent PGA crystallization and melting, during which the typical double melting behavior was present. After thermal measurements, TiO 2 did not show characteristics of a nucleating agent for the PGA fibers. However, it acted as a degradation retardant for low-molecular-weight PGA. Because of its hygroscopicity, anatase, a material with the ability to absorb water, was a more efficient hydrolytic degrader than rutile.