High AC and DC Electroconductivity of Scalable and Economic Graphite-Diamond Polylactide Nanocomposites.

Jacek Fal,Jolanta Sobczak,Gaweł Żyła,Maochang Liu,Katarzyna Bulanda,Sławomir Boncel,Mariusz Oleksy,Jinwen Shi

doi:10.3390/ma14112835

Abstract

Two types of graphite/diamond (GD) particles with different ash content was applied to prepare new electroconductive polylactide (PLA)-based nanocomposites. Four samples of nanocomposites for each type of GD particles with mass fraction 0.01, 0.05, 0.10, and 0.15 were prepared via an easily scalable method—melt blending. The samples were subjected to the studies of electrical properties via broadband dielectric spectroscopy. The results indicated up to eight orders of magnitude improvement in the electrical conductivity and electrical permittivity of the most loaded nanocomposites, in reference to the neat PLA. Additionally, the influence of ash content on the electrical conductivity of the nanocomposites revealed that technologically less-demanding fillers, i.e., of higher ash content, were the most beneficial in the light of nanofiller dispersibility and the final properties.

Highlights

Referring back to the fracture surfaces of GD nanoparticles (Figure 2a) and PLA nanocomposites (Figures 3 and 4), the comparison of electrical conductivity recorded for both types of GD/PLA nanocomposites indicates that the major impact on electrical conductivity enhancement was constituted by the ash content
Nanocomposites (Figures 3 and 4), the comparison of electrical conductivity recorded for both types of GD/PLA nanocomposites indicates that the major impact on electrical conductivity enhancement was constituted by the ash content
The most electroconductive PLA nanocomposites revealed an eight order of magnitudes enhancement in the electrical conductivity without any nanoparticle modification such as surface functionalization. We believe this is a suitable starting point for the development of highly electroconductive PLA nanocomposites readily applicable in electromagnetic interference (EMI) shielding, sensors, or 3D printing electronics

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The electrical properties of newly composed materials such as polymer nanocomposites are very important in many areas of real-life their application. While from the nanofiller point-of-view, these are the carbon nanomaterials which promise the highest potential in the manufacturing electroconductive composites These nanomaterials were commonly applied since they might offer a significant enhancement in the mechanical and/or thermal performance [13]. There are several dozens of works revealing substantial enhancement of the above properties of PLA nanocomposites, but the most prospective effects were obtained for yet uneconomic carbons such as graphene or carbon nanotubes or their mixtures with graphite [14], making the target materials rather arduously scalable. The GD nanoparticles emerged as fully compatible with the PLA matrix enabling scalable melt processing toward the fully functional materials

Materials and Methods

Results and Discussion

Electrical

Conclusions