Fig. 1.

Filtration system characterization: physical and chemical properties. FTIR of the commercial filter (A); DSC of the filter disk (B); TGA and DTGA of the commercial filter (C). Polybutylene terephthalate (PBT) fibers were identified in filter membranes by FTIR spectroscopy (A) by the presence of the terephthalate group, the aromatic group and the stretching of C O of the carbonyl group evident in the FT/IR spectrum, Profiles of TGA curves evidenced membrane stability up to 350 °C both in reactive and inert environment (B), with the main degradation step occurring at around 400 °C. DSC curve showed the glass transition of materials at around 30 °C, and the melting temperature at about 223 °C (C).