Effect of the graphite nanoplatelet size on the mechanical, thermal, and electrical properties of polypropylene/exfoliated graphite nanocomposites

Abstract

Polypropylene (PP)/exfoliated graphite nanoplatelet (xGnP) nanocomposites with various intrinsic aspect ratios of graphite nanoplatelets (GnPs; large and small in diameter) were prepared by a melt-mixing procedure. Transmission electron microscopy showed that all types of xGnP were well-dispersed in the polymer matrix. The effects of the dimensions and loading of the xGnPs on the morphology, mechanical reinforcement, and electrical properties of PP/xGnP were studied. A differential scanning calorimetry study of the PP/xGnP morphology indicated that all types of xGnP additives were heterogeneous nucleation sites for PP crystallization. Tensile testing, DMA, and thermogravimetric analysis of PP/xGnPs with different types of GnP additives showed enhancements in their mechanical properties, heat resistance, and thermal stability compared to plain PP. We also found a significant increase in the conductivity of PP/xGnP. The PP/xGnP with a large diameter of GnPs demonstrated the lowest percolation threshold, equal to 4 vol % of the xGnP loading. The mechanical properties were estimated by means of micromechanical modeling.

A novel route for tethering graphene with iron oxide and its magnetic field alignment in polymer nanocomposites

“…Moreover, due to the treatment using the ultrasonic homogenizer, the GNPs were broken into platelets of smaller sizes, resulting in a lower electrical conductivity when they are used as nanofillers for polymers [55]. …”

Facile preparation of polyamide 6/exfoliated graphite nanoplate composites via ultrasound‐assisted processing

“…Exfoliated graphite nanoplates (xGNPs) are a thin form of graphite with thicknesses ranging from 1 nm to ∼100 nm. The good mechanical, electrical, and thermal conductivities and the low cost make xGNPs an economically viable alternative of graphene for the development of functional and structural nanocomposites . Over the last few years, polymer/xGNP nanocomposites have been developed to prepare high‐performance composites .…”

Tracking the progression of dispersion of graphite nanoplates in a polypropylene matrix by melt mixing

“…This work aims at monitoring the progression of dispersion of as‐received and functionalized GnP in a polypropylene (PP) matrix, using a prototype small‐scale continuous mixer. Indeed, although not studied here, the incorporation of graphene into PP may convey interesting properties to the composite . Functionalized graphite nanoplates (F‐GnP) were obtained by covalent functionalization of the GnP with PP grafted with maleic anhydride (PP‐g‐MA).…”