Antistatic and antimicrobial packaging of PLA/PHBV blend‐based graphene nanoplatelets nanocomposites

Abstract

Graphene nanoplatelets (GNP) were used as a filler for the preparation of antistatic and antimicrobial packaging based on biodegradable blends of poly(acid lactic)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PLA/PHBV) for the electronic components industry. These packages must have low electrical resistivity and mechanical resistance. The use of biodegradable polymers helps to reduce waste and the addition of GNP can also contribute to antimicrobial activity. In this work, the effect of the addition of GNP on the thermal, mechanical, electrical, electromagnetic properties, and antimicrobial activity of the PLA/PHVB blend was evaluated. PLA/PHBV (80/20) blends with the addition of 1, 3, and 5 wt% of GNP were prepared by melt mixing using extrusion and injection‐mold processes. The samples were characterized by mechanical tests (tensile test, and Shore D hardness), thermal (differential scanning calorimetry and thermogravimetric analysis), impedance spectroscopy, electromagnetic interference shielding efficiency (EMI SE), antimicrobial activity, and field emission gun scanning electron microscopy. In general, the addition of GNP contributes to the increase in elastic modulus and Shore D hardness. The percolation threshold was obtained with the addition of 3 or 5 wt% of GNP in the PLA/PHBV blend with a reduction of 3 orders of magnitude in the electrical resistivity, which can be applied to antistatic packaging. All the nanocomposites exhibited antimicrobial activity, and the addition of 5 wt% GNP inhibited 86% of the growth of Escherichia coli. The PLA/PHBV blend‐based GNP nanocomposite with the addition of 5 wt% of GNP presents the best balance of mechanical properties, with low electrical resistivity, greater total shielding effectiveness of EMI SE, and antimicrobial activity.

Renewable PLA/PHBV Blend-Based Graphene Nanoplatelets and Carbon Nanotube Hybrid Nanocomposites for Electromagnetic and Electric-Related Applications

“…The morphology of the injection molded PLA/PHBV blend and nanocomposites with GNP and MWCNT was examined using FEG-SEM (Figures and ) and correlated with the rheological behavior (Figure ). In Figure A,B, it is clearly observed an immiscible blend morphology. , The PLA matrix (80 wt %) contains spherical-like PHBV domains with different sizes, as highlighted by the dashed lines. Some domains had diameters ranging from 1 to 5 μm, while others were smaller than 0.1 μm.…”

“…The electrical conductivity of the blend was increased to commercially viable levels of reflection loss (−15 dB). In another study, Oyama et al (2023) prepared PLA/PHBV (80/20) blend-based graphene nanoplatelets (GNP) nanocomposites with 3 and 5 wt % GNP by twin-screw extrusion. The results indicated an excellent balance of mechanical and electrical properties at 5 wt % GNP, and additional antimicrobial activity.…”