Effects of ultrasound vibration on the structure and properties of polypropylene/graphene nanoplatelets composites

Abstract

An ultrasound-assisted extrusion system was added to melt extrusion process to prepare polypropylene (PP) nanocomposites reinforced with graphene nanoplatelets (GNPs). The relationships among the ultrasound vibration, exfoliation, and dispersion morphology of GNPs in PP matrix, the crystallinity, and the macroscopic properties of nanocomposites were investigated. The properties measurement results showed that the present of ultrasound vibrations increased the conductive properties, decreased the apparent viscosity and crystallinity of PP/ GNPs nanocomposites. FESEM results revealed that the ultrasound vibration increased the exfoliation and dispersion of GNPs in PP matrix. This morphology was benefit for forming electrical and thermal network, therefore the electrical conductivity and thermal conductivity of PP/ GNP nanocomposites were increased. But the powerful vibration that provided by 300 W ultrasound power would reduce the diameter of GNPs, then reduce its conductive properties. FTIR and TGA results showed that ultrasound vibration had less effect on the chemical bond and the degradation of PP/GNPs nanocomposites. POLYM. ENG.

Structural, thermal, rheological and mechanical properties of polypropylene/graphene nanoplatelets composites: Effect of particle size and melt mixing conditions

“…In addition to the characteristic peaks of the α PP crystalline phase, a peak at 2 θ = 26.5° is observed, characteristic of graphene stack reflection (002), and corresponding to an interlayer distance of 0.34 nm . For an equivalent volume fraction, the less intense graphene peak in PP/KNG‐G5 composites indicates a small number of graphene ordered stacks, as observed by He et al with ultrasound treatment during extrusion. Moreover, no graphene peak shift is observed after melt mixing.…”

“…Nevertheless, even though solvent dispersion appears more efficient than melt mixing , the latter is the only technique that can be used at an industrial scale without environmental issues. Recently, authors proposed cryogenic impact milling or ultrasound‐assisted extrusion to enhance the exfoliation of PP/GNP composites.…”

Effect of oxygen functional groups of reduced graphene oxide on the mechanical and thermal properties of polypropylene nanocomposites

“…To have good heat transport properties in the rGO/PP nanocomposites, the phonon scattering or acoustic impedance mismatch at the interface between rGO and polymer matrix should be reduced . The rGO with higher C/O ratio has a better dispersion and thermal contact with non‐polar PP matrix, which will effectively reduce the phonon scattering as well as the interface thermal resistance in the system, thus increasing the thermal conductivity . Besides, the rGO/PP nanocomposites based on rGO with higher C/O ratio have higher degree of crystallinity, leading to more regularly arranged PP molecular chains.…”

Nanocomposite and biodegradable polymers applied to technical textiles

“…Another study by He et al [46] shows the effect on the application of different powers of ultrasonic vibration, with 300 W being the one that manages to reduce the diameter of graphene nanoplates and improves dispersion. This in turn decreases the crystallinity of the nanocomposites, as well as the apparent viscosity of polypropylene (PP) at higher particle content.…”