Study of thermomechanical, structural and antibacterial properties of poly(lactic acid) reinforced with graphene oxide nanoparticles via melt mixing
» Autor: Ioanna?Georgia Athanasoulia,
Petroula A. Tarantili,
» Referencia: doi:10.1002/pi.6054
» Fecha Publicación: 31/05/2020
» Más información
Addition of Graphene oxide (GO) to poly(L?lactic acid) (PLLA) offers an alternative approach to tuning its crystallinity, improving its mechanical properties and transfusing an antibacterial behavior. GO/PLLA nanocomposites were prepared by melt extrusion, thus avoiding the potentially toxic, for biomedical applications, residue of organic solvents. Fourier?transform infrared spectroscopy verified the formation of intermolecular hydrogen bonds. By the differential scanning calorimetry experiments concerning the isothermal crystallization of PLLA and PLLA containing 0.4 wt% GO, a two?dimensional disc?like geometry of crystal growth was determined, whereas at 125 and 130 ?C the nanocomposite developed three?dimensional spherulitic growth. Higher crystallization rate constant (k) values suggest that the incorporation of 0.4wt% GO accelerated the crystallization of PLLA. The lowest crystallization halftime for PLLA was observed at 115?C while, at 110?C, GO caused its highest decrease, accompanied by the highest increase in melting enthalpy (??m), as compared to PLLA's, after completion of isothermal crystallization. Their ??m values increased with Tic, whereas multiple melting peaks transited to a single one, with increasing Tic. GO improved PLLA's thermal stability, tensile strength and Young's modulus. Incorporation of 0.8 wt% GO endowed PLLA with another potential application as biomaterial since the deriving composite presented good thermomechanical properties and effective prohibition of Escherichia coli bacteria attachment and proliferation. This effect was more prominent under simulated sunlight exposure than in the dark. The preparation method did not compromise the intrinsic properties of GO.This article is protected by copyright. All rights reserved.