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In this work, electrospun nanofibers based on polylactic acid, PLA, reinforced with ZnO nanoparticles have been studied, considering the growing importance of electrospun mats based on biopolymers for their applications in different fields. Specifically, electrospun nanofibers based on PLA have been prepared by adding ZnO nanoparticles at different concentrations, such as 0.5, 1, 3, 5, 10 and 20 wt%, with respect to the polymer matrix. The materials have been characterized in terms of their morphological, mechanical, and thermal properties, finding 3 wt% as the best concentration to produce PLA nanofibers reinforced with ZnO nanoparticles. In addition, hydrolytic degradation in phosphate buffer solution (PBS) was carried out to study the effect of ZnO nanoparticles on the degradation behavior of PLA-based electrospun nanofiber mats, obtaining an acceleration in the degradation of the PLA electrospun mat.

[EN] The aim of this work is to obtain electrospun materials from polylactic acid (PLA) reinforced with nanoparticles of zinc oxide (ZnO) for potential medical and piezoelectric applications. PLA is a biodegradable and biocompatible biopolymer and zinc oxide has a proven antimicrobial effect. Furthermore, both materials have piezoelectric properties. The obtained materials have been characterized to study the reinforcing effect that nanoparticles can have on the PLA polymeric matrix. Firstly, samples of unreinforced and reinforced nanofibres with the content of 0.5, 1, 3, 5, 10, 20% by weight of zinc nanoparticles have been prepared. Fibres with a preferential orientation have also been studied to compare the effect of the configuration on the final properties. A study of the diameter distribution, orientation, and morphology of the nanofibres has been carried out by scanning electron microscopy. Thermal analysis has been carried out by difference scattering calorimetry and thermogravimetric analysis. Crystallinity has been studied by X-ray diffraction and the mechanical properties using a tensile strain-stress experiment. Finally, given the medical interest, a study of in vitro degradation of randomly distributed samples has been done., [ES] El presente trabajo tiene como objetivo la obtención de materiales electrohilados de ácido polilactico (PLA) nanorreforzados con nanopartículas de óxido de cinc (ZnO) para sus potenciales aplicaciones biomédicas o piezoeléctricas. El PLA es un biopolímero, biodegradable y biocompatible y el óxido de cinc tiene un probado efecto antimicrobiano. Además, ambos materiales presentan propiedades piezoeléctricas. Los materiales obtenidos han sido caracterizados a fin de estudiar el efecto reforzante que puedan tener las nanopartículas en la matriz polimérica de PLA. Primero, se han preparado muestras de nanofibras no reforzadas y reforzadas aleatoriamente distribuidas con un contenido del 0,5; 1; 3; 5; 10 y 20% en peso de nanopartículas de cinc. También se han estudiado fibras con una orientación preferencial, para comparar el efecto de la configuración en las propiedades finales del material. Sobre las nanofibras se ha realizado un estudio de la distribución de diámetros, orientación y morfología por microscopía electrónica de barrido. Se ha realizado un análisis térmico por medio de calorimetría diferencia de barrido y análisis termogravimétrico. La cristalinidad se ha estudiado por difracción de rayos X, y las propiedades mecánicas por un ensayo mecánico de tracción simple unidireccional. Por último, dado el interés médico de estos materiales se ha hecho un estudio de la degradación in vitro de las muestras aleatoriamente distribuidas.