Tuning the mechanical and electrical conductivity properties of graphene‐based thermoplastic starch/poly(lactic acid) hybrids

Abstract

Environmentally friendly approaches were followed to develop thermoplastic starch (TPS)/poly(lactic acid) (PLA) extruded hybrids at 70:30 and 30:70 compositions, with the incorporation of reduced graphene oxide at 1.0, 3.0, and 5.0 mass% contents. Glucose was chosen as reagent to reduce graphene oxide (GO) to the rGO sample. Theoretical models predicted that the final location of rGO was at the interface of the components. The adhesion between the polymeric phases in the hybrids, observed by scanning electron microscopy, and the improved compatibilization suggested by mechanical and dynamic mechanical analyses indicated that a large fraction of rGO platelets were at the interface. X‐ray diffraction showed that rGO acted as a nucleating agent for PLA and revealed a better dispersion of rGO lamellae within TPS. Consequently, the phase composition of the TPS/PLA/rGO hybrids played an important role on the properties of the hybrids. For the neat TPS/PLA blend at 70:30 composition, ɛmax = (4.7 ± 0.6)% and the electrical conductivity was found around 10−13 S/cm. The incorporation of rGO led to more flexible and to higher conductivity materials, with ɛmax = (15.1 ± 0.7)% and σ = 1.1 × 10−5 S/cm for the hybrid with rGO at 5.0 mass% content. POLYM. COMPOS., 40:E1131–E1142, 2019. © 2018 Society of Plastics Engineers

Preparation and Properties of Poly(lactic Acid)/Thermoplastic Starch/Reduced Graphene Oxide Composites

“…This result denoted the restoration of a large part of the conjugated graphitic structure in the rGO‐g product, by the reduction of GO with glucose. The same GO and rGO‐g samples were recently characterized by other techniques, which confirmed the effectiveness of the glucose‐induced reduction …”

“…The same GO and rGO-g samples were recently characterized by other techniques, which confirmed the effectiveness of the glucose-induced reduction. [16] rGO-g was dispersed in ATBC plasticizer and incorporated to the TPS/PLA blend by melt extrusion. The structure and crystallinity of the compression-molded composites were investigated by XRD ( Figure 2).…”

Extrusion of Polymer Nanocomposites with Graphene and Graphene Derivative Nanofillers: An Overview of Recent Developments

“…Therefore, the recent interest in the development of biodegradable materials has attracted increasing attention towards PLA nanocomposites [100]. Table 4 summarizes the very last PLA-graphenic composites prepared by means of melt blending [101][102][103][104][105][106][107][108][109][110][111] and other biodegradable and biocompatible polymers [112][113][114][115][116][117].…”

Influence of graphene nanoscrolls on the crystallization behavior and nano‐mechanical properties of polylactic acid

“…Therefore, understanding the crystallinity of PLA allows for the estimation and modification of its properties . Recent studies indicated improvements in electrical conductivity and flexural strength of crystallized PLA on graphene . Similarly, crystallized PLA possess shape memory attributes with higher storage modulus, which is owing to an ordered lamellar structure of crystallized PLA .…”

“…20 Recent studies indicated improvements in electrical conductivity and flexural strength of crystallized PLA on graphene. 21 Similarly, crystallized PLA possess shape memory attributes with higher storage modulus, which is owing to an ordered lamellar structure of crystallized PLA. 22 PLA is biocompatible, however, the sharp nano-walls of graphene could kill bacterial cells, providing antibacterial attributes to PLA-graphene nanohybrid.…”