Investigation into the effects of fillers in polymer processing

• Main Authors: Jiayi Zhu, Chamil Abeykoon, Nazmul Karim
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2021-09-01
• Series: International Journal of Lightweight Materials and Manufacture
• Subjects: Nano-composites; Silica nanoparticle; Graphene; Nano-fillers; Energy consumption; Twin screw extrusion
• Online Access: http://www.sciencedirect.com/science/article/pii/S2588840421000160

The addition of fillers has become a common method of improving the performance of composites. Therefore, many types of fillers are commercially available while several other types are being investigated. The understanding of the effect of additives on the processing and product quality is crucial for manufacturing products economically and with the desired qualities. This study focuses on investigating the possible effects of graphene and fumed silica nanoparticle fillers on polymer processing and product properties. Three polymeric materials were processed with these two fillers via a Mini-Lab twin screw extruder to obtain a better dispersion, and then the properties of samples produced were explored with a number of different testing techniques (e.g., tensile testing, SEM, DSC and rheometer). The Young's modulus of amorphous materials was strongly affected by the filler content, while crystalline materials were not that sensitive to the filler content/level. The Young's modulus of polystyrene-based polymer nanocomposites (PNCs) with 8 wt% fillers at 200 °C and 50 rpm was found to be of approximately 1786 MPa. Also, as clearly recognized by the SEM images and one glass transition temperature (Tg) value rather than two Tg values, it can be ensured that the particles are finely dispersed within PNCs regardless the filler type/content. And then, the rheological results further confirmed that the properties of PNCs are affected by the filler content and set conditions, while the Tg of PNCs was mainly dependent on the matrix and have slightly influenced by the degree of filler dispersion. Moreover, the energy demand was also explored during all the experimental trials for possible comparison and indicated that the energy consumption increased with the filler content but the magnitude of increase was different with different polymer type.