Polypropylene composites reinforced with hybrid inorganic fillers: Morphological, mechanical, and rheological properties

Mineral fillers like talc and mica are commonly used in the plastic industry because of their tendency to alter the properties of thermoplastic materials. Polypropylene (PP)-talc (PTC), PP-mica (PMC), and PP-talc/mica hybrid composites (PHC) were prepared. Results indicated that filler particle size, type, and content greatly influence the mechanical and rheological properties of the composites. Shear viscosity decreased with the increase in shear rate. At 40 degrees C, an increase of approximately 120% in storage modulus (E) was observed in PMC composites. C parameter increased, whereas reinforcing efficiency (r) decreased with the increase in filler loading. Percent elongation of each type of composites decreased with the increase in filler loading. Tensile modulus of PTC composite increased significantly by 103% (571 MPa) at 20% loading of talc, whereas for PHC and PMC composites, increase of 93% (543 MPa) and 81% (511 MPa) was observed. Flexural modulus also increased considerably by 88% (2413 MPa), 80% (2313 MPa), and 62% (2084 MPa) of PTC, PHC, and PMC composites at 20% filler loading.