Structural, Thermal, Morphological, Adsorption and Catalytic Properties of Poly(BPDAH-co-ODA/PPDA)-Ag/V2O5 Nanocomposites

Thermally stable polyimides (PIs) were prepared by condensation technique at 160 ºC for 5 hours in N-methylpyrrolidone (NMP) medium under N2 atmosphere both in the presence and absence of metal (Ag) and metaloxide (MO) (V2O5) nanoparticles (NPs). The synthesized polymers are characterized by Fourier Transform Infra Red (FT-IR) spectroscopy, 1H Nuclear Magnetic Resonance (1H NMR) spectroscopy, Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray (FE-SEM and EDX). The FT-IR spectrum showed a peak at 1786 cm-1 corresponding to the C=O stretching of dianhydride. The aromatic proton signals appeared between 6.7 and 7.5 ppm in the 1H-NMR spectrum of the resultant PIs. The oxydianiline (ODA) based PI with Ag NP loaded system exhibited the highest Tg value. The apparent rate constant values for the adsorption and catalytic reduction of p-nitrophenol (PNP), Cr6+ and rhodamine 6G (R6G) dye were determined with the help of UV-visible spectrophotometer. Among the catalysts, the system loaded with V2O5 NP has higher kapp values. The experimental results are critically analyzed and compared with the previously available literature values. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis and spectral characterizations of poly(congored) grafted silk fibre — A kinetic approach

172-179Silk fibre has been grafted with poly(congored) (PCR) dye in an aqueous medium under different experimental conditions like temperature, weight of silk fibre and concentration of CR dye in the absence of mordant’s and fixing agents. The grafting kinetics of PCR onto silk fibre is quantitatively followed by spectroscopy (UV-visible and fluorescence spectra) method. The thermodynamic parameters, number of binding sites, binding constant, and nature of quenching system are determined from the kinetic data. The chemical grafting of PCR onto silk fibre is confirmed by FTIR, UV-visible and fluorescence spectra. The conductivity measurements, cyclic voltammetry measurement and FE-SEM analysis also supports the chemical grafting of PCR onto silk fibre