This study aims to examine how different amounts of red mud (RM) (0, 10, 20, 30, and 40 wt.%) affect the dynamic mechanical and thermal characteristics of polypropylene (PP)/red mud (RM) polymer composites. Fourier Transform Infrared Spectroscopy (FTIR) was used to confirm the presence of PP and RM in the samples. The distribution of RM in the PP matrix was analysed using Scanning Electron Microscopy (SEM). X-ray Diffraction (XRD) results showed that crystallinity of polypropylene increased from 80.04% for pure PP to 94.94% for the composite containing 40 wt% red mud. Thermogravimetric Analysis (TGA) was employed to analyse the thermal stability of the polypropylene (PP)/red mud (RM) polymer composites. Specifically, it was used to assess the thermal stability of the composites, with results indicating excellent stability for the 40 wt.% RM composites. Differential Scanning Calorimetry (DSC) was used to compare the melting temperatures (Tm) of the composites. There is a slight increase in Tm, from 169.08 °C for pure polypropylene to 171.45 °C for the composite with 40 wt% red mud. Furthermore, Dynamic Mechanical Analysis (DMA) results revealed a 58% reduction from the storage modulus of the pure polypropylene (6.28 × 10⁸ Pa) to the storage modulus of the composite containing 40 wt% red mud (2.60 × 10⁸ Pa).
The research highlights that red mud (RM) waste is a low-cost, sustainable filler material in a polypropylene matrix. It enhances thermal stability and structural performance for various engineering applications.