CHEMICAL, PHYSICAL, STRUCTURAL AND MORPHOLOGICAL CHARACTERIZATION OF RECYCLED MATERIALS TO PROMOTE THE CIRCULAR ECONOMY IN ITALIAN MANUFACTURING (CPSMR)

The increasing incorporation of recycled plastics into industrial value chains represents a central pillar of circular economy strategies, yet their quality and reliability remain limited by intrinsic material heterogeneity and insufficient characterisation methodologies. Unlike virgin polymers, inorganic fillers, degradation products, and trace contaminants accumulated over successive life cycles. Conventional quality indicators based on mechanical or physical properties are therefore inadequate to fully describe their structural and chemical state, particularly in the context of End-of-Waste classification and regulatory compliance. This work develops and validates multi-technique analytical framework for the comprehensive characterisation of recycled polymer materials. Fourier Transform Infrared (FTIR) spectroscopy was applied for polymer identification and detection of polymer mixtures; X-ray Powder Diffraction (XRPD) was used to identify mineral filler phases; Scanning Electron Microscopy coupled with Energy-Dispersive X-ray spectrometry (SEM-EDX) provided microstructural and compositional mapping of fillers and contaminants; and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) enabled quantitative determination of bulk and trace elements, including regulated heavy metals. These methods were selected through experimental screening and inter-laboratory validation to ensure robustness when applied to heterogeneous, additive-rich recyclates. These results reveal that industrial recycled plastics frequently contain mixed polymer systems, heterogeneous filler distributions, and cumulative trace-metal contamination. Calcite, talc, rutile, and glass fibres were identified as dominant fillers, while Fe, Cu, Zn, Cr, Ni, Pb, and Sb were detected as recurring contaminants. These features strongly influence microstructural integrity, ageing behaviour, and material performance. The integrated analytical framework developed here provides a scientifically grounded basis for assessing recycled plastic quality and supports the development of reliable End-of-Waste and circular economy strategies. Keyword: Recycled plastics, polymer mixture, Mineral fillers, trace metals, FTIR, XRPD, SEM-EDX, ICP-MS, Circular economy, End-of-Waste, Material characterisation