Preparation of Polypropylene Foams with Micro/Nanocellular Morphology using a Sorbitol-based Nucleating Agen

The effect of a sorbitol-based nucleating agent on expanded polypropylene (EPP) bead foaming and extrusion foaming was investigated. The main purpose of this study was to study and develop a fundamental processing baseline for the production of nanocellular foams.;During the EPP bead foaming experiments using different concentrations of a sorbitol-based nucleating agent, NX8000, foams having a sub-micron sized cells (10 12 cells/cm3) was obtained at optimized processing conditions. The mechanism of bubble nucleation utilizing small sized crystals induced by the addition of NX8000 was found to be significantly affecting the foaming behaviour of PP.;The effect of NX8000 was not apparent in extrusion foaming process. High shearing force disturbed the network structure of NX8000. Further development of extrusion system that can preserve the nanocellular template during the process is required.