Study of thermomechanical, structural and antibacterial properties of poly(lactic acid) reinforced with graphene oxide nanoparticles via melt mixing

Abstract

Addition of graphene oxide (GO) to poly(l‐lactic acid) (PLLA) offers an alternative approach for 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. Using 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 values suggest that the incorporation of 0.4 wt% GO accelerated the crystallization of PLLA. The lowest crystallization half‐time for PLLA was observed at 115 °C, while at 110 °C GO caused its highest decrease, accompanied by the highest increase in melting enthalpy (ΔHm), as compared to that of PLLA, after completion of isothermal crystallization. Their ΔHm values increased with Tic, whereas multiple melting peaks transited to a single one with increasing Tic. GO improved the PLLA thermal stability, tensile strength and Young's modulus. Incorporation of 0.8 wt% GO endowed PLLA with another potential application as a biomaterial since the derived 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. © 2020 Society of Chemical Industry

Bamboo Charcoal/Poly(L-lactide) Fiber Webs Prepared Using Laser-Heated Melt Electrospinning

“…Recently, the development of ultrafine PLLA fibers blended with particles acquired from natural and biodegradable resources, including bamboo charcoal (BC), has become an interesting topic of research for improving the properties of ultrafine PLLA fibers. For protective applications [ 27 ], outdoor protective products with UV-shielding properties have attracted considerable attention because of the limitation of PLLA caused by its high transparency [ 22 , 28 ]. Powder-like BC carbonized from bamboo is a renewable, non-toxic, and antibacterial material with highly conductive, deodorizing, and UV-shielding properties [ 29 , 30 ].…”

Atomic layer deposition of ZnO on PLA/TiO2 bionanocomposites: Evaluation of surface chemistry and physical properties toward food packaging applications

“…The inhibitory effect across the entire contact area (6 mm) of the uncoated films could be attributed to a number of reasons. First, it could be related to the photoreaction mechanism on the PLA surface, a mechanism generated upon exposure to an intense UV environment using a UV source, 73 however it is possible even upon prior mild exposure to UV irradiation via natural light, 74,75 which is the case of our experiments, resulting in the production of reactive oxygen species (ROS) that can damage the bacterial cell walls. In addition, the inhibitory effect could be also related to the photocatalytic activity of TiO 2 when exposed to ultraviolet light, generating various ROS, such as O 2 − , • OH, HO 2 • , and so on, in the presence of water and oxygen species, that cause oxidative stress to the bacteria 76 .…”

Silane functionalization of WS2 nanotubes for interaction with poly(lactic acid)

“…Poly(lactic acid) (PLA) is a biodegradable thermoplastic of interest in biomedical and biopolymer materials research, with applications as diverse as tissue engineering, cardiovascular implants, dental niches, drug carriers, orthopaedic engineering, cancer therapy, skin and tendon healing, and in medical tools and equipment. 28–37 However, PLA, depending on the d - and l -isomer content can have poor properties including a high degree of brittleness and low gas barrier properties. 38 Consequently, given the excellent combination of WS 2 NT mechanical and biocompatible properties, reinforcement of PLA for Bioresorbable Vascular Scaffolds (BVS) 39,40 and bone tissue engineering 41,42 are of great interest.…”

“…Poly(lactic acid) (PLA) is a biodegradable thermoplastic of interest in biomedical and biopolymer materials research, with applications as diverse as tissue engineering, cardiovascular implants, dental niches, drug carriers, orthopaedic engineering, cancer therapy, skin and tendon healing, and in medical tools and equipment. [28][29][30][31][32][33][34][35][36][37] However, PLA, depending on the D-and L-isomer content can have poor properties including a high degree of brittleness and low gas barrier properties. 38 Consequently, given the excellent combination of WS 2 NT mechanical and biocompatible properties, reinforcement of PLA for Bioresorbable Vascular Scaffolds (BVS) 39,40 and bone tissue engineering 41,42 are of great interest.…”