Functionalised graphene effect on the mechanical and thermal properties of recycled PA6/PA6,6 blends

Abstract

Limiting the generation of polymers waste and maximizing their recyclability and recovery have been the main focus of the research and industry in recent years. Recycling of polyamides leads to the loss in mechanical and thermal properties, therefore, in order to reuse recycled nylons, an enhancement in their properties is desired. Enhancing the properties of recycled polyamides by the addition of functionalised graphene nanoparticles (GNPs) was the goal of this study. Recycled PA6/PA6,6 blends and functionalised graphene nanocomposites were prepared using hot-melt extrusion process. Two types of functionalised graphene were used: O2-GNPs and Amine-GNPs. The nanofillers didn’t affect the crystallinity of the recycled nylon, while the presence of functionalised graphene increased the thermal conductivity by enabling better heat transfer routes within the polymer. The microstructure of the materials was characterised confirming the successful dispersion but with a slight variation in GNPs/Polymer bonding depending on the functionalisation type. The strong nylon-to-graphene interfacial hydrogen bonding increased the mechanical properties of the recycled nylon nanocomposites. The functionalised nanoparticles slowed down the segmental motion of the polymer chain and decreased the ductility with increasing GNPs contents up to 10 wt%. The overall behaviour of recycled nylon nanocomposites showed dependency on the type of functionalisation and concentration of GNPs with better improvement in the overall properties using 2 wt% Amine-GNPs. These enhanced properties make functionalised graphene/recycled nylon nanocomposites a promising new class of advanced materials.

Valorization of nylon and viscose-rayon textile yarn wastes for fabricating nanocomposite films

“…The tensile strength increased by 23.82% with the addition of fibers, and lower crystallinity was observed with the addition of NFC/MFC and CNC. Apart from cellulosic fillers, graphene has been previously added to the recycled nylon-6 matrix to enhance the tensile strength of the films at a lower concentration of 2 wt% [28]. In another study impact strength of recycled nylon-6 was improved by 55.5% with the addition of Hytrel (elastomer) [29].…”

Carboxyl graphene reinforced melamine-based polyamide nanocomposites

“…25 Korkees et al studied recycled PA6/ PA6,6 blends-graphene nanocomposites; the results showed that the thermal conductivity of nanocomposites was improved using functionalised graphene. 26 As a result, it appears that combination of solution mixing and melt blending is the only way to achieve better graphene dispersion in polymeric materials with exceptional properties. 9 In this study, the delamination/adsorption method 18,27 is applied in which dimethylacetamide solvent is used to make novel carboxyl graphene/melamine-based polyamide (CGMPA) nanocomposites.…”

“…25 Korkees et al studied recycled PA6/PA6,6 blends-graphene nanocomposites; the results showed that the thermal conductivity of nanocomposites was improved using functionalised graphene. 26 As a result, it appears that combination of solution mixing and melt blending is the only way to achieve better graphene dispersion in polymeric materials with exceptional properties. 9…”

PA6/PA66/talc composite: Effect of reprocessing on the structure and properties

“…10 They can be filled with graphene nanoparticles, glass fiber and talc to improve their properties or simply to reduce cost. [10][11]12 Studies regarding reprocessing of neat PA6, neat PA66, clay, talc and glass fiber filled polyamides have been carried out. Some authors [13][14][15] have investigated the effect of reprocessing on the mechanical properties of PA6 and observed a decrease in strain at break and impact strength and an increase in tensile strength and elastic modulus.…”