This paper presents the reuse process of post-consumer printed foils made of glycol-modified poly(ethylene terephthalate) (PETG). Fourier-transform infrared spectroscopy and a scanning electron microscope confirmed that these foils consist of PETG and PS layers. Firstly, foil pieces were immersed in the organic solution to remove all prints and after washing and drying they were extruded into regranulate rPETG pellets. Three types of PETG/rPETG blends were fabricated with the addition of 10, 20 and 30 wt% of virgin PETG. Microscopic analysis of the blends confirmed their homogeneity, as was also shown by the fact that there was only one glass transition peak in the heating curve given by differential scanning calorimetry. Moreover, in the presence of fresh PETG the degradation temperatures of rPETG improved significantly, and the viscosity of all blends was reduced as a result of shortened macromolecule chains in rPETG. Mechanical analysis of the materials showed that all blends have comparable tensile strength and a Young’s modulus that is higher than rPETG but lower than virgin PETG. Elongation at break decreases together with the content of rPETG.

Carbon fibre-reinforced polymers (CFRPs) are commonly used in aviation, automotive and renewable energy markets, which are constantly growing. Increasing the production of composite parts leads to increased waste production and a future increase in end-of-life components. To improve the recyclability of CFRPs, new materials that fit in with the idea of a circular economy should be used as a composite matrix. One such material is a commercially available thermoplastic liquid resin, Elium® (Arkema, France). In this work, the authors investigated how the mechanical recycling process affects the properties of thermoplastic-based carbon fibre composites. CFRPs with neat Elium® resin and resin modified with 0.02 wt.% single-walled carbon nanotubes or 0.02 wt.% multi-walled carbon nanotubes were manufactured using the resin infusion process. Afterwards, prepared laminates were mechanically ground, and a new set of composites was manufactured by thermopressing. The microstructure, mechanical, thermal and electrical properties were investigated for both sets of composites. The results showed that mechanical grinding and thermopressing processes lead to a significant increase in the electrical conductivity of composites. Additionally, a sharp decrease in all mechanical properties was observed.

The first report of using limonene derivative of a spherosilicate as a modifier of polylactide used for 3D printing and injection moulding is presented. The paper presents the use of limonene-functionalized spherosilicate derivative as a functional additive. The study compared the material characteristics of polylactide modified with SS-Limonene (0.25–5.0% w/w) processed with traditional injection moulding and 3D printing (FFF, FDM). A significant improvement in the processing properties concerning rheology, inter-layer adhesion, and mechanical properties was achieved, which translated into the quality of the print and reduction of waste production. Moreover, the paper describes the elementary stages of thermal transformations of the obtained hybrid systems.

The aim of this research was to improve the electrical and mechanical properties of carbon-fibre-reinforced polymers (CFRP) based on thermoplastic acrylic resin ELIUM^®, by introducing single-walled carbon nanotubes (SWCNTs) into their structure. The laminates were fabricated using the infusion technique of infiltrating the carbon fabric with the mixture of acrylic resin and SWCNTs. The addition of SWCNTs improved the electrical conductivity through the thickness of the laminate by several times compared to the laminate without modification. No defects or voids were observed in the structure of the fabricated nanocomposites. The introduction of SWCNTs into the CFRP structure increased the Young’s modulus, interlaminar shear strength and impact resistance. DMA analysis showed almost no change in the glass transition temperature of the fabricated SWCNT/CFRP nanocomposites compared to the reference laminate.