Use of recycled polystyrene to manufacture filtration membranes: an experimental investigation

This study has the aim to investigate the possibility to use recycled polystyrene (PS) as feedstock for the preparation of membranes. Considering that recycling is becoming a consolidated reality, it is fundamental to explore other possibilities and see if a recycled material can substitute a conventional product. Moreover, it is relevant to understand which are the advantages and limitations of this new approach, to define the possible applications on actual processes. In particular, the goal is to produce a reliable membrane, with a narrow pore size distribution, that should be suitable for filtration applications, considering that membranes made of recycled polymers are a developing field and that polystyrene is not commonly used for membrane production, due to its hydrophobicity and due to its fragility when casted. Using the E.T.E. technology (Emulsified Thermoplastic Engineering) it is possible to obtain recycled PS from food packaging, which was then used for the membrane production by phase inversion, along with NaCl and several types of PEG as porogens. The samples are then tested to evaluate their properties in terms of permeability, porosity and rejection, to understand the suitability of this material and to possibly define an application.