Synthesis, characterization, and heavy metal ion adsorption studies of polyamides, polythioamides having pendent chlorobenzylidine rings

Abstract

Aromatic polyamides and polythioamides with pendent chlorobenzylidine rings were synthesized through direct polycondenzation of 2-(p-chlorobenzalimino) terephthalic acid with the diamines 4,4 0 -oxidianiline (1a), 4,4 0 -methylenediamide (1b), 4,4 0 -diaminodiphenyl sulfone (1c), and thioamines 4,4 0 -(bisthiourea) diphenyl ether (3a), 4,4 0 -(bisthiourea) diphenyl methane (3b), 4,4 0 -(bisthiourea) diphenyl sulfone (3c), respectively, in DMF using P(OPh) 3 /pyridine. The polymers were precipitated using water as nonsolvent. FTIR and 1 H-NMR spectroscopic analysis was used to characterize the monomers and polymers. Representative polyamides and polythioamides were used for the removal of heavy metal ions such as Pb(II), Cd(II), Cu(II), and Cr(III) from aqueous solutions. The effects of pH, contact time, and initial concentration on the uptake of metal ions have been investigated. The adsorption capacities under competitive conditions were in the order Pb (II) > Cu (II) > Cr (III) > Cd (II). The adsorbed ions were eluted by treatment with 2N HCl, and the activities of the polymers are retained after fourth regeneration.

Adsorption of Cu(II), Ni(II) and Pb(II) ions onto polyamine-polyurea polymer modified with pyromellitic dianhydride: kinetic, isotherm and thermodynamic studies

“…These results show that a modification of PPP with PMDA improved the adsorption capacity of the polymer. The comparisons of the maximum adsorption capacity of metal ions using various polymer adsorbents are listed in Table 2 [3,22,27,29,30,[39][40][41].…”

“…The superiorities of chelating polymers to adsorb heavy metals are their ease of use and the fact that they can be repeatedly used, along their high adsorption capacity and selectivity [13,17]. In the literature, there are numerous reports where chelating polymers have been used to remove and recover heavy metal ions from wastewater [18][19][20][21][22]. Adsorption of some metal ions using polyamine-polyurea resin has been reported in the literature [23].…”

Synthesis, Characterization and Metal Ion Adsorption Studies on Novel Aromatic Poly(Azomethine Amide)s Containing Thiourea Groups

“…Recently, Schiff based polymers of chitosen and thiourea based polymers were developed for the removal of Cu 2+ and other metal ions [22][23][24]. Our group is currently concentrating on the synthesis of novel polymers bearing hetero atoms in the polymer back bone for the efficient removal of heavy metal ions [25][26][27][28]. In this study new ladder type poly(azomethine amide)s having phenyl thiourea groups were synthesized, characterized and their potential application as adsorbents for the removal of Cu 2+ and Cd 2+ from aqueous solutions were explored.…”

Poly-L-Histidine Attached Poly(glycidyl methacrylate) Cryogels for Heavy Metal Removal

“…A thorough review of the literature reveals that membrane filtration, ion exchange systems, chemical precipitation, electroplating, adsorption process, photo catalysis and electrochemistry are used for removal of heavy metal ions from aqueous solutions (6)(7)(8)(9)(10). Recently, Kumar et al prepared organic-inorganic hybrid adsorbent based on EDTA and silica (11).…”