Synthesis, characterization, and metal-ion uptake studies of chelating resins derived from formaldehyde-condensed azodyes of aniline and 4,4 '-diaminodiphenylmethane coupled with phenol/resorcinol
S. Samal et al., Synthesis, characterization, and metal-ion uptake studies of chelating resins derived from formaldehyde-condensed azodyes of aniline and 4,4 '-diaminodiphenylmethane coupled with phenol/resorcinol, J APPL POLY, 77(14), 2000, pp. 3128-3141
The diazonium salts of aniline and 4,4'-diaminodiphenylmethane coupled with
phenol and resorcinol were condensed with formaldehyde in alkaline media t
o yield polymeric resins. These polymers were found to readily react with m
etal ions like Cu2+ and UO22+, forming polychelates. The azodyes, resins, a
nd polychelates were characterized by several instrumental techniques such
as elemental analysis, FTIR, H-1-NMR, GPC, XRD, TG-DTG, and DSC studies. Th
e chelating capacity of the resins toward Cu2+ and UO22+ ions was studied b
y spectrophotometry. The extent of metal loading of the resins was studied
by varying the time of contact, metal-ion concentration, and pH of the reac
tion medium. The alkali and alkaline earth metal ions had little effect on
the metal-ion uptake behavior of the resins. The resin derived from the azo
dye of 4,4'-diaminodiphenylmethane was found to be more efficient in removi
ng the metal ions from solution than were the resins from aniline. The opti
mum conditions for effective separation of Cu2+ from UO22+ were determined.
(C) 2000 John Wiley & Sons, Inc.