Effect of incorporation of graphene oxide and graphene nanoplatelets on mechanical and gas permeability properties of poly(lactic acid) films

Abstract

Nanocomposite thin films of poly(lactic acid) (PLA) were produced incorporating small amounts (0.2 to 1 wt%) of graphene oxide (GO) and graphene nanoplatelets (GNP). The films were prepared by solvent‐casting. Mechanical properties were evaluated for plasticized (by residual solvent) and unplasticized films. Plasticized nanocomposite films presented yield strength and Young's modulus about 100% higher than those of pristine PLA. For unplasticized films improvements in tensile strength and Young's modulus were about 15 and 85%, respectively. For both film types, a maximum in mechanical performance was identified for about 0.4 wt% loadings of the two filler materials tested. Permeabilities towards oxygen and nitrogen decreased, respectively, three‐ and fourfold in films loaded with both GO or GNP. The glass transition temperature showed maximum increases, in relation to unloaded PLA films, of 5 °C for 0.4 wt% GO and 7 °C for 0.4 wt% GNP, coinciding with the observed maxima in mechanical properties. Copyright © 2012 Society of Chemical Industry

Effects of Graphene Nanoplatelets and Reduced Graphene Oxide on Poly(lactic acid) and Plasticized Poly(lactic acid): A Comparative Study

“…In principle, it would be expected that the incorporation of rGO would lead to a stronger reinforcement effect than the incorporation of Graphene Nanoplatelets (xGnP), considering that the rGO exist in an exfoliated individual graphene sheets which had an even higher aspect ratio than xGnP. There are many studies on graphene composites based on a range of polymers available in literature, e.g., polycarbonate [16], Nylon [17], poly(methyl methacrylate) [18], poly(vinylidene fluoride), epoxy [19], poly(vinyl alcohol) [20], polystyrene [21], poly(ethylene disulfide) [22], poly(propylene) [23], poly(lactic acid) [24,25], etc. An investigation on the mechanical aspects of epoxy/xGnP by Chanrasekaran et al [19] showed that effective mechanical reinforcement was achieved for 0.5 wt% with 17% increase in glassy storage modulus.…”

High‐Performance Multifunctional Graphene‐PLGA Fibers: Toward Biomimetic and Conducting 3D Scaffolds

“…Table 1 compares the mechanical properties of the PLGA composite fibers with PLGA-based nanocarbon composites in previously published reports (in the form of either films or fibers). The ultimate strength, reported here, was much higher than those reported for PLGA composite with solvent exfoliated graphene [73] , graphene oxide [41][42][43][44][45][46] , graphene nanoplatelet [41,74] , carbon nanotubes [75] and carbon nanofibers [76] . Our average modulus was also considerably higher than all of them.…”

“…Thin coating --10 ohm/sq [87] Graphene oxide PLGAReinforcement Mechanical properties Films 2-4 50-60 Not reported [41] Graphene oxide PLGAReinforcement Mechanical properties Films 3.385 60 Not reported [42] Graphene oxide PLGAReinforcement Mechanical properties Films 0.96 10.9 Not reported [43] Graphene oxide PLGAReinforcement Thermomechanical Properties Films 0.31 3.4 Not reported [44] Graphene oxide PLGAReinforcement Thermomechanical, surface chemical properties Electrospun Fibers 0.075 3.4 Not reported [45] Graphene oxide PLGABiocompatibility Surface properties Films Not reported Not reported Not reported [46] Graphene …”

“…Oxidative exfoliation of graphite results in a processable, but, non-conducting form of graphene, the so-called graphene oxide (GO) [23] . GO-based composites are favorable when the target is to improve the mechanical performance, although the inherent conductivity of graphene can be partially restored [35,[41][42][43][44][45][46][47] . Solvent exfoliation of graphite uses a solvent for the exfoliation process to give graphene in the liquid phase (monolayer and few layers) without any additional oxidation step or defect formation [48] .…”

“…The main challenge is to induce electrical conductivity and improve the mechanical performance of the whole structure simultaneously, while preserving the inherent chemistry, biocompatibility and cytocompatibility of the original PLGA [46,49] . Moreover, the ability to construct 3D…”