Innovative hybrid nanocomposites of recycled polyethylene terephthalate/polyamide 11 reinforced with sepiolite and graphene nanoplatelets

This research delves into the novel development of hybrid nanocomposites using recycled polyethylene terephthalate (rPET)/polyamide (PA11) with sepiolite, enhanced by the integration of Graphene Nanoplatelets (GNP). Five different formulations were produced using co-rotating twin-screw extrusion and injection moulding techniques. The optimal blend, which includes equal amounts of sepiolite and graphene nanoplatelets (phr, 1 part per hundred resin each), exhibited a tensile strength of 54.5 MPa, representing an increase in tensile strength by 46.5% and an increase in percent strain by 59% as the GNP content increased from 0.2 to 1 phr, replacing sepiolite. Young’s modulus of hybrid nanocomposites varied between 1020 and 1285 MPa, indicating a significant enhancement. Flexural strength in the best-performing hybrid nanocomposite containing 1 phr of sepiolite and 1 phr of GNP (HNC-G1.0) increased by 61.65% to 76.46 MPa from 47.3 MPa (HNC-G0.0). In contrast, its flexural modulus reached 2668 MPa from HNC-G0.0 (1730 MPa), demonstrating substantial improvements. The impact strength also showed a notable 83% rise from HNC-G0.0 (252.97 J/m) to 463.18 J/m (HNC-G1.0). Despite these mechanical enhancements, Thermo Gravimetric Analysis (TGA) demonstrated the thermal stability of the nanocomposites. At the same time, Differential Scanning Calorimetry (DSC) confirmed that the melting temperature remained stable, ensuring consistent processing conditions. This innovative research paves the way for advanced applications of rPET, particularly in the automotive industry. It marks a significant advancement in polymer science, promoting sustainable solutions and high-performance hybrid nanocomposites.