A novel approach for dissolving crystalline LDPE using non-toxic solvents for membranes preparation

Membrane preparation via phase inversion requires the use of solvents that presents in most cases a significant risk to health. Hence, the substitution of toxic solvents by others greener or more sustainable choices becomes a need. In this work, more sustainable solvents such as butyl acetate and liquid paraffin were used to prepare recycled low-density polyethylene (LDPE) flat membranes via thermally induced phase separation method. A comparison using xylene as a solvent, ethanol as a non-solvent and alumina as a pore-former was also carried out to evaluate the differences of both produced membranes. The crystalline properties of the polymer were studied via Fourier transform infrared spectroscopy with the aim of revealing differences in functional groups between the various membranes. The characterization of these membranes in terms of thickness, contact angle, pore size, porosity and SEM analyses showed that the addition of alumina had an important role in improving essentially the porosity and the contact angle. As expected, the results of LDPE-alumina membranes revealed good porosity with a hydrophobic moiety.