Eco-Friendly Polythiophene(keto-amine)s Based on Cyclopentanone Moiety for Environmental Remediation

Abstract

Eco-friendly polythiophene(keto-amine)s 4 a–e containing thiophene-arylidene-thiophene tri-blocks moieties in polymers backbones have been synthesized and characterized for environmental remediation. The synthetic method has been carried out by the interaction of the monomer 2 with different aromatic, cyclic and aliphatic diamines. The polymerization had occurred using polycondensation process in dry benzene as solvent. A new monomer namely, 2,5-bis[4-choloro-acetyl(thiophen-2-ylmethylene)]cyclopentanone 2 was firstly synthesized using the normal condition of Friedel–Crafts reaction by the reaction of 2,5-bis(thiophen-2-ylmethylene)cyclopentanone 1 with chloroacetyl chloride in the presence of aluminum chloride anhydrous. The structure of the new monomer as well as polymers was confirmed by elemental and spectral analyses. Furthermore, solubility, viscometry, SEM and thermal characteristics for the new polymers were tested. All the polymers were freely soluble in formic acid as good example for polar protic solvents. PDTmax and FDT for all the polymers were detected and were in the range 434–467 and 487–533 °C respectively. On the other hand, the analytical competition of the newly synthesized PTKA polymers 4 a and 4 c was also evaluated for a selective extraction of metal ions prior to their determination by inductively coupled plasma-optical emission spectrometry mainly for environmental remediation. The selectivity of PTKA 4a and PTKA 4c towards different metal ions, including Cd(II), Co(II), Cu(II), Cr(III), Fe(III), Ni(II) and Zn(II), was studied. Results of the selectivity study demonstrated that 4 a and 4 c polymers was the most selective towards Cr(III) and Co(II). Adsorption capacity of 4a for Cr(III) was improved by 38.37% in comparison to that of 4 c for Co(II) after only 1 h contact time. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on homogeneous adsorbent surfaces of both PTKA 4 a and PTKA 4 c.