Carbon fiber reinforced polymer (CFRP) composites have very high specific properties, which is why they are used in the aerospace, wind power, and sports sectors. However, the high consumption of CFRP compounds leads to a high volume of waste, and it is necessary to formulate mechanical recycling strategies for these materials at the end of their useful life. The recycling differences between cutting-end mills and high-energy ball milling (HEBM) were evaluated. HEBM recycling allowed us to obtain small recycled particles, but separating their components, carbon fiber, epoxy resin, and CFRP particles, was impossible. In the case of mill recycling, these were obtained directly from cutting a CFRP composite laminate. The recycled materials resulted in a combination of long fibers and micrometric particles—a sieving step allowed for more homogeneous residues. Although long, individual carbon fibers can pass through the sieve. Ultrasonication did not significantly affect HEBM recyclates because of the high energy they are subjected to during the grinding process, but it was influential on end mill recyclates. The ultrasonication amplitude notably impacted the separation of the epoxy resin from the carbon fiber. The end mill and HEBM waste production process promote the presence of trapped air and electrostatics, which allows recyclates to float in water and be hydrophobic.

Polyurethane (PU) is one of the most commonly used plastics, typically synthesized from diisocyanates and polyols derived from non‐renewable or unsustainable sources. This study proposes a synthesis route for polyurethanes that originates from bio‐based polyols. The polyols were obtained through the metathesis depolymerization of butadiene rubber using fatty alcohol and Hoveyda‐Grubbs second‐generation catalyst (HG2), resulting in hydroxyl‐terminated polybutadiene (HTPB). FT‐IR and GPC analyses confirmed the successful synthesis of polyols, indicating molecular weights between 535 and 2200 g/mol. Three polyurethanes (PU1, PU2, and PU3) were synthesized using these bio‐based polyols, while a fourth polyurethane (PU0) was produced with polyethylene glycol as a standard polyol for comparative property analysis. FT‐IR analysis identified the characteristic signals and functional groups of the polyurethanes. TGA and DSC evaluated the thermal properties of the polyurethanes, revealing decomposition temperatures (T _max ) between 300 and 450°C. PU materials were practically amorphous, as shown by XRD. SEM micrographs illustrated the varying morphologies of the polyurethanes, providing deeper insights into their properties. This synthesis process is vital for recycling rubber waste, transforming it into hydroxy‐terminated compounds, HTPB, or polyols using vegetable oils and renewable resources. When integrated into PU synthesis, these compounds promote the development of sustainable materials and significantly contribute to environmental conservation and the sustainable production of adhesives, paints, and coatings, among other valuable products.

Nowadays, additive manufacturing technologies (AM) suffer from insufficient or lacking methodologies/techniques for quality control. This fact represents a key technological barrier preventing broader industrial adoption of AM, particularly in high-value applications where component failure cannot be accepted. This article presents a real-time melt pool segmentation and monitoring technique applicable to the direct laser metal deposition (LMD) process. An infrared camera with an InSb detector (resolution of 640 × 480, spectral range between 3 and 5 μm) was used. An algorithm, called gravitational superpixels, is presented. This algorithm can group pixels and generate superpixels based on a block generation technique that compares color similarity and temperature in infrared images. Besides, a color similarity correction is applied to reduce uncertainty in segmentation, as well as for eliminating the image background. The task of extracting edges is based on the law of universal gravitation. A quantitative and qualitative algorithm performance analysis, which uses standard metrics, is presented. The analysis demonstrates better versatility than reduction/feature extraction or image segmentation approaches by high-/low-pass filtering. The experimental validation was carried out, extracting and measuring the molten pool geometry and its thermal signature. Then, measures were compared against ground truth and against results obtained by other similar methods. The proposed gravitational superpixel method has higher precision and performance. Our proposal has a significant potential for monitoring industrial AM processes since it requires minimal modifications of commercially available industrial machines.