Synthesis of polyamides contains pyridine and xanthene pendant group: study of optical, thermal, antibacterial activity and hexavalent chromium ion adsorption

Abstract

Two series of new polyamides were synthesized based on xanthene and pyridine from new diamines and common dicarboxylic acids. The pyridine and xanthene rings were formed during the monomer process synthesis. The diamines and polyamides structure were completely explained using FT-IR, 1H-NMR and 13C-NMR. Xanthene presence as bulky pendent groups, improved the polyamides solubility and also induced good antibacterial activity. All of the polyamides were amorphous in nature with weight average molar mass (Mw) up to 50,200 g mol−1 and inherent viscosities (0.59–0.78 dL/g). Polyamides showed fluorescence emission upon irradiation with quantum yields in the range 8–21%, with respect to the presence of xanthene and pyridine groups in their structure. The polyamides indicated the glass transition temperatures (Tg) about 195–268 °C and 10% weight loss temperatures (T10%) in the range of 338–402 °C in N2. In addition, by the synthetic diamines asymmetrical structure, changes that made to the polymers properties were investigated. In the following, the study of chromium adsorption property of hexavalent of prepared polymers was conducted by polyacrylonitrile membrane modification with one of the synthesized polyamides by the use of electrospinning method in different hexavalent chromium concentrations.