Abstract
Plastic waste accumulation requires effective recycling approaches for converting secondary polymer resources into value-added materials. In this work, recycled polypropylene/high-density polyethylene (PP/HDPE) blends obtained from mixed plastic waste were processed by melt compounding and modified with 5 wt.% industrial talc. The study focused on the processability, mechanical properties, morphology, and chemical stability of recycled polyolefin composites. PP/HDPE blends with ratios of 9:1 and 7:3 exhibited stable extrusion behavior and sufficient pellet yield, whereas the 5:5 blend showed poor processability. Talc addition increased the stiffness of the composites, with the elastic modulus reaching 634.16 MPa for PP/HDPE 9:1 + 5 wt.% talc and 563.77 MPa for PP/HDPE 7:3 + 5 wt.% talc. SEM analysis showed that the mechanical behavior was affected by phase heterogeneity, filler dispersion, and local defect formation. FTIR spectra confirmed the preservation of the polyolefin structure and the absence of significant oxidative degradation after processing. The results demonstrate the potential for converting mixed recycled polyolefin waste into functional composite materials suitable for industrial applications and sustainable resource use.