Effect of processing method on the properties of multifunctional exfoliated graphite nanoplatelets/polyamide 12 composites

Thermoplastic Carbon/Polyamide 12 Composites Containing Functionalized Graphene, Expanded Graphite, and Carbon Nanofillers

“…Several groups achieved remarkable reinforcement of polymer matrices including PA 12 by incorporating GnPs and FGs . However, with exception of a recent study presented by Kalaitzidou and coworkers, compression molding and fiber spinning has been applied, albeit melt extrusion and injection molding are prominent in commercial PA 12 processing. Therefore, one aim of this study was placed upon the investigation of carbon (nano)filler influence on Young's modulus, tensile strength, and elongation at break of injection‐molded PA 12.…”

“…The obtained results correspond to the individual aspect ratios, the quantity of stacked carbon nanosheets and the state of filler dispersion, as presented before. In view of layer‐morphological fillers, the incorporation of TRGO‐ and MLG 350‐percentage affords superior matrix reinforcement (+89%) with respect to GnP/PA 12, which exhibits substantially lower tensile modulus improvement in the range of +30 at 5 wt% GnP content . In opposite, the addition of EG 60, containing micron‐sized graphite stacks, yields rather poor reinforcement, owing to the absence of graphene distribution during melt processing and decreased carbon/matrix interfaces.…”

“…CB, CNT, and FGs as well as CB/CNT hybrids are well known as polymer additives to improve the electrical conductivity of PA 12 . Yet, the formation of percolating network‐like structures is rather sensitive to many parameters such as processing conditions, sample geometry, and experimental setup, which frequently prevents a direct comparison of the obtained results.…”

“…Yet, CB offers inferior aspect ratio and CNT can cause severe dispersion problems that require special dispersion techniques or tedious CNT functionalization necessitating expensive additional processing steps. During recent years, graphene nanoplatelets (GnP), consisting of stacks of more than 10 graphene layers, and FG have been employed in PA 12 melt compounding . Various applications based on injection‐molding, selective laser sintering, or film and fiber formation describe GnP‐based PA 12 nanocomposites with increased crystallinity, improved stiffness, tensile strength as well as electrically conductive behavior.…”

“…During recent years, graphene nanoplatelets (GnP), consisting of stacks of more than 10 graphene layers, and FG have been employed in PA 12 melt compounding. [52][53][54][55][56][57] Various applications based on injection-molding, selective laser sintering, or film and fiber formation describe GnP-based PA 12 nanocomposites with increased crystallinity, improved stiffness, tensile strength as well as electrically conductive behavior. Song and coworkers [52,57] reported increased tensile strength (þ35%), enhanced K Ic -toughness (þ72%) and reduced oxygen-permeability (-32%) for compression-molded FG/PA 12 nanocomposites at low carbon content of 0.6 wt%, yet neither affecting polymer stiffness nor electrical conductivity.…”