Comparative study of virgin and recycled polyethylene terephthalate and polypropylene intermingled thermoplastic composites

Abstract In this study, a comparative analysis of the use of recycled PET (R‐PET) in synthetic and natural fiber blended composites was made. PET, R‐PET, and PP yarns were folded with reinforcing fibers by commingling technique and then fabrics were prepared using weaving technology. Hot compression molding technology was used for composite fabrication. Tensile and impact characterization revealed the significant influence of reinforcing and TP fibers on mechanical properties. R‐PET matrix glass fiber reinforced composites exhibited 41.77% higher tensile strength than virgin PET and 20.41% higher than PP. In terms of tensile strength for linen reinforced samples, R‐PET shows an impressive 181% improvement over virgin PET and 154% over PP. According to the drop weight test results, glass fiber reinforced R‐PET matrix sample exhibited a peak load value 53% higher than that of the virgin PET matrix, although it was 9.47% lower than the PP matrix. In linen fiber reinforced samples, R‐PET demonstrated a 57.73% improvement over virgin PET but lower by 9.47% compared to the PP matrix. During this time, DSC, TGA, FTIR, and flammability tests were also performed on the composite samples. The results showed that R‐PET has easy processability as a matrix material and provides better wetting of the reinforcing fibers. For this reason, it has been shown that R‐PET matrix samples provide better mechanical properties than both PET and PP matrix samples. It has also been determined that R‐PET is a more suitable matrix material compared with natural fiber reinforced composites. Highlights Commingled yarns were used for preparing composites. R‐PET yarns were used as matrix in preparing glass and linen reinforced composites. R‐PET was compared with virgin PET and PP yarns. R‐PET showed great potential in easy preparation of TP composites. Composites made with R‐PET showed improved thermal and mechanical properties.