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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Dairy and Functional Foods Research » Research » Publications at this Location » Publication #351809

Research Project: In Vitro Human Intestinal Microbial Ecosystem: Effects of Diet

Location: Dairy and Functional Foods Research

Title: Processable conductive and mechanically reinforced polylactide/graphene bionanocomposites through interfacial compatibilizer

item CAI, CHENYANG - Nanjing Forestry University
item Liu, Linshu
item FU, YU - Nanjing Forestry University

Submitted to: Polymer Composites
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2018
Publication Date: 11/22/2017
Citation: Cai, C., Liu, L.S., Fu, Y. 2017. Processable conductive and mechanically reinforced polylactide/graphene bionanocomposites through interfacial compatibilizer. Polymer Composites.

Interpretive Summary: The shells of many types of electrical and electronic appliances are made from metal or thermo-conductive plastics from petroleum sources. These materials possess the appropriate mechanical properties demanded by the application and emit heat that is generated during operation. However, these materials are not biodegradable or compostable at their end of useful life, and thus raise deep environmental concerns. In this study, we present new materials made from poly(lactic acid (PLA), derived from corn starch, and nanosized graphite. The PLA contributes its strong mechanical properties to the shell, while the nanosized graphite allows heat to pass easily from one side to the other. To improve the adherence of PLA to nanosized graphite, a small portion of the PLA was chemically modified (ma-PLA) to bridge the graphite with the PLA resulting in further improvement of the mechanical properties. The PLA can be degraded by microorganisms in the soil to lactic acid, which is non-toxic and environmentally benign. Graphite is a naturally occurring inorganic material and is abundant in the earth. This research may present a solution to the environmental pollution that has plagued the electrical and electronic industries for years.

Technical Abstract: Novel processable conductive bionanocomposites containing different loadings of graphite nanoplatelets (GNPs) were developed and examined in the experiments. At the same GNPs loadings, the bionanocomposites with interfacial compatibilizer, maleated PLA (ma-PLA), exhibited higher mechanical and thermomechanical properties compared to neat PLA and those without ma-PLA. The strong interaction from incorporated interfacial compatibilizer with GNPs was evidenced on the fractured surface. With the micromechanical models, the mechanical properties of the bionanocomposites were evaluated. Also, their thermal and rheological properties were tested and analyzed. An approximately twofold decrease in complex viscosity was achieved for the bionanocomposites with interfacial compatibilizer. For electrical conductivity, at 5–7 wt% GNPs loadings the electrical conduction path was constructed inside the PLA matrix through the formation of the effective three-dimensional conductive networks. It was interestingly noted that above the percolation threshold the increasing GNPs loading did not contribute to the higher but lower AC conductivity. The corresponding mechanisms in AC conductivity were elucidated and discussed.