Process for producing microporous thin film from plastic waste stream

Abstract

Polypropylene (PP) and polyethylene (PE) blends derived from plastic waste streams and a method to prepare reusable oil sorbents. A method includes separating plastics of group-A from group-B using a float-sink technique, where group-A comprises various PP and PE materials, and group-B comprises polystyrene, polyethylene terephthalate, and polyvinyl chloride; dissolving the group-A plastics in a solvent; adding a cavity forming agent to the solution; applying the solution onto a solid substrate through spin-coating followed by controlled heating; and extracting the cavity forming agent, obtaining a thin film sorbent with swellable cavities for oil sorption. The film contains 400-800 swellable 3D cavities/cm, each cavity capable of swelling 20-30 times the thickness of the film when contacted with oil. The method improves compatibility of PP-PE blends without using compatibilizers, resulting in high oil uptake capacity due to swellable cavities, and reusability of sorbent with an oil recovery of more than 98%.