High-performance engineering thermoplastics offer lightweight and excellent mechanical performance in a wide temperature range. Their composites with carbon nanotubes are expected to enhance mechanical performance, while providing thermal and electrical conductivity. These are interesting attributes that may endow additional functionalities to the nanocomposites. The present work investigates the optimal conditions to prepare polyether ether ketone (PEEK)/multi-walled carbon nanotube (MWCNT) nanocomposites, minimizing the MWCNT agglomerate size while maximizing the nanocomposite electrical conductivity. The aim is to achieve PEEK/MWCNT nanocomposites that are suitable for melt-spinning of electrically conductive multifilament’s. Nanocomposites were prepared with compositions ranging from 0.5 to 7 wt.% MWCNT, showing an electrical percolation threshold between 1 and 2 wt.% MWCNT (10⁷–10² S/cm) and a rheological percolation in the same range (1 to 2 wt.% MWCNT), confirming the formation of an MWCNT network in the nanocomposite. Considering the large drop in electrical conductivity typically observed during melt-spinning and the drawing of filaments, the composition PEEK/5 wt.% MWCNT was selected for further investigation. The effect of the melt extrusion parameters, namely screw speed, temperature, and throughput, was studied by evaluating the morphology of MWCNT agglomerates, the nanocomposite rheology, and electrical properties. It was observed that the combination of the higher values of screw speed and temperature profile leads to the smaller number of MWCNT agglomerates with smaller size, albeit at a slightly lower electrical conductivity. Generally, all processing conditions tested yielded nanocomposites with electrical conductivity in the range of 0.50–0.85 S/cm. The nanocomposite processed at higher temperature and screw speed presented the lowest value of elastic modulus, perhaps owing to higher matrix degradation and lower connectivity between the agglomerates. From all the process parameters studied, the screw speed was identified to have the higher impact on nanocomposite properties.

Technical clothing with light-responsive features for outdoor sports practiced in environments with low visibility is extremely important for athletes’ safety. Lack of signaling by users and visibility for drivers is one of accidents causes, namely run overs, which can leave serious consequences. The products available on the market lack efficiency and their design is not appealing which makes the development of these new materials a compelling need. Therefore, fluorescent and phosphorescent functional finishings with ability to provide illuminant signalization without compromising the design and/or color of clothing as well as comfort and ergonomics, were developed and applied in the textile structure by knife over roll coating technology. The greatest challenge is to integrate the high visibility materials without compromising the design of the garment and accomplish the European Standard of Protective clothing: Enhanced visibility equipment for medium risk situations and test methods and requirements—EN 17353 (that supersedes EN1150:1999 and allows more freedom in the design of the apparel) published in 2020. Phosphorescent materials were evaluated by luminance decay according to DIN 67510, before and after fastness to wash tests. Results obtained regarding high visibility functional finishings and the integration of the materials developed in the final sports collection will be presented.