## 5 Future, Perspectives, and Research Gaps  
Research conducted under the LIDER 14/0270/2023 project focuses on the modification of plastic composites with additives aimed at enhancing the mechanical strength of the composite and imparting special properties such as luminescence, flame retardancy, and antistatic behavior [115]. For instance, typical PET (polyethylene terephthalate) recycling processes are mainly used for producing new bottles--issues arise with contaminated feedstock, which cannot be utilized in applications involving food contact. Therefore, it is crucial to explore applications where the presence of contaminants such as adhesives, labels, or residual chemicals does not pose limitations in the material's reprocessing. One such area is structural components in civil and municipal engineering, where food-contact certification is irrelevant. This approach enables the effective use of contaminated PET in sectors that do not require high purity of materials.  
The potential use of modified and reinforced polymers as base materials for load-bearing chains exemplifies how the construction industry can adopt advanced materials  
Figure 9: Highly stressed regions in the chain during operation.  
to meet contemporary demands. Recycling materials--especially those requiring minimal processing--offers an opportunity to repurpose waste into durable, high-performance components. This strategy aligns with sustainable development principles and allows for the production of materials with unique properties. Numerous industrial sectors may benefit from substituting currently used materials with high-quality recyclates.  
Recent findings from our previous studies [72,73] have demonstrated the clear benefits of reinforcing recycled polyethylene terephthalate (rPET) with glass fibers (GFs), highlighting this approach as a promising pathway to improve the mechanical performance of recycled polymers. The incorporation of GFs into the rPET matrix significantly enhances tensile and flexural strength, stiffness, and thermal stability, with tensile strength increasing by up to 255% in composites containing 50% GF (rPET50 GF) compared to neat rPET. Moreover, the resulting composites exhibit reduced deformability and increased rigidity, making them suitable for structural and load-bearing applications. These improvements not only extend the usability of rPET into advanced engineering domains, such as automotive components, but also contribute to circular economy goals by enabling high-performance reuse of post-consumer plastics. However, the influence of GF on melt viscosity and the processing behavior of rPET/GF composites suggests that injection molding parameters must be carefully optimized for each formulation.  
As part of the ongoing project, further research activities are currently being carried out. The results of these studies will be presented at international scientific conferences and published in peer-reviewed journals. Two patent applications (No. P.452128/No. P.452131) have been submitted as part of the research, covering a proprietary method for producing a composite formulation for chain link manufacturing. Based on this applications, the LIDER project envisions the production of a composite chain link with electrical insulation properties. Furthermore, the developed formulation will also be used to fabricate a bonded anchor designed for securing the chain to rock or concrete substrates.