Investigating the significance of waste tire rubber on processability, compatibility, and rheological properties of magnetorheological elastomers

Transforming waste into valuable resources is a key goal in the global pursuit of sustainability. This study investigates the integration of waste tire rubber (WTR) as part of the matrix in magnetorheological elastomers (MREs), on its impact on processability, compatibility, and rheological properties. MREs unique properties enable active control of the rheological parameters under magnetic fields, with developed applications in vibration damping, isolators, peristaltic pumps, and soft robotics. While previous research mainly explores the effects of magnetic particles on MRE performance, the influence of WTR loading on the MRE matrix remains underexplored. Therefore, this work addresses this gap by systematically evaluating WTR loading (0–30 phr) in MREs, with a focus on optimizing WTR levels to improve their sustainability without compromising performance. Our findings showed that low WTR concentrations (5–10 phr) enhanced scorch time and processability, but higher concentrations reduced processability. The molecular compatibility between the WTR and NR blends of MRE is confirmed by Fourier Transform Infrared (FTIR) spectroscopy analysis. Meanwhile, Scanning Electron Microscopy (SEM) showed interfacial compatibility at lower loadings. Additionally, rheological analysis demonstrated a linear viscoelastic (LVE) region from ~ 0.01% to 1.42% (WMRE10 sample) and the highest MR effect of 7.60% (WMRE5 sample). This research presents a substantial advancement in the development of smart materials by providing insights into optimizing WTR loading for MRE performance and promoting sustainability through waste reduction and resource recovery.