Efectos del tratamiento térmico y del método de colección sobre la estructura cristalina de las nanofibras electrohiladas de ácido poli (láctico)

Abstract

Previous studies indicate that poly (lactic acid) (PLA) nanofibers obtained by electrospinning report a low mechanical strength. Therefore, it is intended to show the changes in the mechanical properties of Young’s modulus and tensile strength of PLA nanofibers due to the type of collection and thermal treatment. For this, PLA nanofibers were prepared by electrospinning collected randomly, and orderly with thermal treatment was carried out at 80 ºC for 8 hours to increase the cross-linking and the crystalline phase of the scaffolding. The nanofibers were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), low angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and stress evaluation. The results showed oriented nanofibers with a clearly defined semicrystalline structure and a smaller average fiber diameter and a notorious increase of tensile strength concerning those collected randomly. Additionally, the thermal treatment influenced the average diameter and the porosity of the scaffolding but did not generate a significant change in the mechanical properties. Therefore, it is concluded that the rotary collection process generates a higher molecular order, increase in the mechanical properties under study, while annealing extends the crystallinity of the nanofibers but does not affect these properties.