Facile Preparation of Open-Cell PP/TPS Blend Foams Using Water as a Blowing Agent

Extrusion foaming using water as a blowing agent offers a green process of preparing polymer foams. Due to the low water solubility of hydrophobic polymers such as polypropylene ( PP), it is difficult to produce low-density foams of such pure polymers. In this study, starch was utilized as an effective water carrier and open-cell PP/ thermoplastic starch (TPS) blend foams with apparent density as low as 19.5 kg center dot m-3 and open-cell content of 95.6% were successfully prepared. A possible expansion mechanism is also proposed to better understand the observed foaming behavior. The PP/ TPS blend foams with low density and high open- cell content are found to be a promising candidate absorbent material for oil spill cleanup application.