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

Abstract

Thin films of polyglycolic acid (PGA), a biodegradable and biocompatible polymer, were prepared by electrospinning and were studied according to their molecular weights. TiO2 nanoparticles were also used as additives at concentrations of 2–8 wt%. The films were morphologically characterized and exhibited a homogeneous distribution of TiO2 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 TiO2 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, TiO2 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, TiO2 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.