Magnetic, thermal stability and dynamic mechanical properties of beta isotactic polypropylene/natural rubber blends reinforced by NiZn ferrite nanoparticles

The dispersion of magnetic nanoparticles in matrix is crucial to ensure optimum performance of the composite. The difficulty level of achieving good dispersion is further increase when a multi-phases of matrix is present. A pre-coating technique of magnetic nanoparticles with polypropylene using ball-mill prior to melt-blending process was employed to prepare a multi-phases thermoplastic natural rubber composite. The effect of filler loading (2 wt%-10 wt%) on morphology, structure, magnetic properties, thermal stability and dynamic mechanical properties of the composites were investigated. It was found that the NiZn ferrite nanoparticles act as nucleating agent to form beta isostatic polypropylene thermoplastic composites. The composites' magnetic properties are directly dependent on the filler concentration. The dispersion of magnetic fillers in polymer matrix plays role in affecting the magnetic properties and thermal stability. The preference of filler to locate at amorphous phase has distorted the chain orientation of natural rubber and polypropylene. Hence, the polymorphism and crystallinity of the matrix varied as the filler loading increased, affecting the dynamic mechanical properties. It was found that 8 wt% NiZn nanocomposite exhibits highest E' and tanδ, indicating the dynamic mechanical properties of NiZn nanocomposite are affected by β-phase degree.