(593d) Incorporating Upcycled Laboratory Waste into Membranes

Polystyrene (PS) and polymethyl methacrylate (PMMA) are two plastics widely used in laboratory settings due to their low cost and ease of disposal. Unfortunately, they are often not recycled, with the vast majority of waste ending up in landfills. Furthermore, current recycling processes tend to produce inferior materials due to harsh processing conditions, which presents a unique opportunity to mature the concept of a circular polymer economy by drawing upon techniques and knowledge from the field of membrane science. Advancing upcycling strategies aimed at integrating these waste materials into membrane fabrication processes has the potential to alleviate some aspects of plastic pollution, while also yielding economic and societal benefits. This study probes the structure-property-performance relationship of blending waste PS and/or PMMA with polyethersulfone (PES) to determine how incorporating these waste plastics can preserve or enhance water filtration membrane separation characteristics. Spectrophotometer cuvettes were used as the PMMA material while Petri dishes were primarily used as the PS material. PES and waste plastics were combined with dihydrolevoglucosenone (Cyreneâ„¢) and/or other solvents to produce polymer solutions. Flat-sheet membranes were successfully fabricated using the nonsolvent-induced phase separation (NIPS) method. Waste plastics were evaluated with Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) to gain insight on polymer properties and to determine if any processing additives or co-polymers were present. Contact angle goniometry was used to evaluate the contact angle and surface free energy of the membranes. Scanning electron microscopy (SEM) was used to characterize the cross-sectional and top surface morphologies of fabricated membranes. Pure water permeance and solute rejection of fabricated membranes were quantified with dead-end filtration. Current data suggest PS and PMMA tend to decrease the hydrophilicity and narrow the pore size distribution of the membrane surface.