Esponja de poli(dimetilsiloxano) funcionalizada com grupo amino para adsorção de metais em meio aquoso

Abstract

Polymeric sponges can be applied in the most diverse areas, mainly due to its ease of handling and removal from the medium in which it was used. In this work, sponges were prepared from a polydimethylsiloxane polymer matrix (PDMS), a chemically inert and hydrophobic polymer. The surface of this matrix was modified by amino-functional silane groups, through catalyzed polycondensation reactions, for the obtained polymer network contained functional groups on its surface and lower hydrophobicity. In addition, the cavities were generated using a template, which was removed efficiently at the end of the preparation. To obtain a stable sponge, some of the synthesis parameters were varied: PDMS molar mass, order of reagent insertion, ratio of surface amino groups, solvent and catalyst. The prepared materials were characterized by Infrared Spectroscopy, Thermogravimetric Analysis, Differential Scanning Calorimeter, Scanning Electron Microscopy and swelling tests. The developed sponges presented high thermal stability, flexibility, high degree of swelling in polar and nonpolar solvent. The sponge prepared with 65 cSt PDMS, on the proportion of 1:0,25 PDMS:APTMS m/m and used dibutyltin dilaurate as catalyst (sponge TPACL 65 1:0,25) presented the best results in terms of properties and application. The sponges can remove metallic ions from aqueous solutions, saturating the surface in 72 hours. Removal capacity of Cu (II), via the adsorption process, was about 2.00 mmol (127 mg) per gram of material. Therefore, this work presents promising results for environmental remediation, when it comes to the removal of copper in water.