Melt processing and characterisation of polyamide 6/graphene nanoplatelet composites

Abstract

Composites of Linear Low Density Polyethylene (LLDPE) and Graphene Nanoplatelets (GNPs) were processed using a twin screw extruder under different extrusion conditions. The effects of screw speed, feeder speed and GNP content on the electrical, thermal and mechanical properties of composites were investigated. The inclusion of GNPs in the matrix improved the thermal stability and conductivity by 2.7% and 43%, respectively. The electrical conductivity improved from 10 -11 to 10 -5 S/m at 150 rpm due to the high thermal stability of the GNPs and the formation of phonon and charge carrier networks in the polymer matrix. Higher extruder speeds result in a better distribution of the GNPs in the matrix and a significant increase in thermal stability and thermal conductivity. However, this effect is not significant for the electrical conductivity and tensile strength. The addition of GNPs increased the viscosity of the polymer, which will lead to higher processing power requirements. Increasing the extruder speed led to a reduction in viscosity, which is due to thermal degradation and/or chain scission. Thus, while high speeds result in better dispersions, the speed needs to be optimized to prevent detrimental impacts on the properties.

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

“…While little changes occur in cold crystallization and melting temperature. Similar results were reported by other research [37]. FTIR was measured to reveal the effect of ultrasound vibration on the chemical bond of PP/GNPs nanocomposites, as shown in Fig.…”

Super tough graphene oxide reinforced polyetheretherketone for potential hard tissue repair applications

“…At higher concentration the fillers tend to agglomerate and act as inclusions that facilitate the voids nucleation around them during plastic deformation. Under such condition, the fillers actually serve as stress concentration sites that facilitate the crack initiation and propagation, compromising the overall composite structural integrity and reduced the energy dissipation ability of the composites [41]. Since the G band of GO is at 1595cm -1 and that of the benzene ring is at 1600 cm -1 [35,47,48], it is hard to distinguish between the two.…”

Effect of two types of graphene nanoplatelets on the physico–mechanical properties of linear low–density polyethylene composites

“…16 Under melt mixing, the constituent materials experience high levels of mechanical shear, which plays an important role in the materials produced. 17 Linear low-density polyethylene (LLDPE) is routinely processed via melt mixing and has significant commercial importance due to its good balance of mechanical properties and processability compared to other types of polyethylene (PE). 18 Addition of fillers can enhance the physical and mechanical properties of PE for various applications, such as electromagnetic reflective materials and high voltage cables.…”

“…The improvements are linked mostly to the change in crystallinity, tensile strength, thermal conductivity, electrical properties and thermal stability. [17][18][19] In this paper, we investigate the effect of adding two grades of GNPs in contents ranging from 1 to 10 wt% in an LLDPE matrix. We report the detailed characterization of the physical and mechanical properties of the resulting LLDPE nanocomposites, and the effect of the GNP size and morphology on these properties.…”