Effect of interfacial modification on functional properties of polyethylene and polypropylene—Fibrous silica nanocomposites

This paper reports the results of polyethylene (PE) and polypropylene (PP) composites containing 5 and 10 wt.% dendritic fibrous nanosilica (DFNS) synthesized by a hydrothermal process. The objective of this investigation is to provide a better understanding of the relationship between the structure, composition, matrix-nanofiller interfaces, and the properties of these nanocomposites. These materials have been prepared by twin-screw extrusion and injection molding. Their structural, thermal, mechanical, rheological, and electrical properties were evaluated, both alone and when combined with an organic compatibilizing agent. Findings have shown that the unique morphology of fibrous silica nanoparticles was preserved and not altered by melt processing, indicating the high thermal and mechanical stability of these fibrous materials. The nanocomposites containing DFNS alone exhibited higher mechanical performances compared to those containing the surface modifier, with no observable effect on their thermal properties. Findings also showed that the interactions between the nanoparticles and polymer may influence the functional properties of the final nanocomposites, and that they are dependent on both the nature of the host polymer along with the presence of the surface modifier agent. Highlights: Well-defined DFNS were successfully prepared. PE and PP based nanocomposites were successfully designed by twin-screw extrusion. Good interfacial interactions were obtained with PP. Functional properties of the nanocomposites were influenced by the interfacial adhesion.