Evaluation of physicochemical properties and catalytic activity of poly(PMDAH-co-ODA/PPDA) nanocomposites towards the removal of toxic pollutants

Chemosphere. 2021 May;271:129890. doi: 10.1016/j.chemosphere.2021.129890. Epub 2021 Feb 9.

Abstract

Synthesis of Polyimides (PIs) between pyromellitic dianhydride (PMDAH) and oxydianiline (ODA) or p-phenylenediamine (PPDA) in the presence and absence of V2O5 and Ag nanoparticles (NPs) were carried out under N2 atmosphere at 160 °C for 5 h with vigorous stirring in N-methylpyrrolidone (NMP) solvent. The prepared PI and its nanocomposites were analyzed by FT-IR spectroscopy, 1H NMR spectroscopy, FE-SEM, SEM, DSC and TGA like analytical instruments. The FE-SEM showed various surface morphologies for different PI nanocomposites. The particle size of the prepared nanoparticles was calculated as less than 60 nm for Ag and 15 nm for V2O5 nanoparticles by HR-TEM. The PI nanocomposites embedded with Ag nanoparticles (P2 and P5) showed a higher thermal stability than the pristine PIs (P1 and P4) and PI/V2O5 nanocomposites (P3 and P6). Further, the possible application of metal (Ag) and metal oxide (V2O5) NPs embedded PI nanocomposites was assessed on the catalytic reduction of highly toxic Cr(VI), Rhodamine 6G (R6G) dye and p-nitrophenol (NiP) pollutants with the help of a reducing agent (NaBH4). The apparent rate constant (kapp) values were calculated to assess the catalytic efficiency of the prepared PI and its nanocomposites. The PI/Ag nanocomposite (P2) system showed an efficient catalytic reduction than the other systems.

Keywords: Catalysis; Cr(VI); Polyimides; R6G dye; k(app).

MeSH terms

  • Benzoates
  • Catalysis
  • Environmental Pollutants*
  • Metal Nanoparticles*
  • Nanocomposites*
  • Silver
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Benzoates
  • Environmental Pollutants
  • pyromellitic dianhydride
  • Silver