Authors : Gurnule W.B. and Khobragade J.V.
Page Nos : 252-260
Description :
Pthallic acid
–
melamine
-
formaldehyde copolymer resin was synthesized through the
condensation of pthallic acid and melamine with formaldehyde in the presence of hydrochloric acid as a
catalyst and with various molar ratios of the reacting monomers. The
resulting copolymer was
characterized with UV
-
visible, FTIR,
1
H
-
NMR and C
13
NMR spectral data, employed to determine the
reactivity of monomers. The average molecular weight of this resin was determined with conductometric
titration in a non
-
aqueous medium
. The chelating ion
-
exchange properties were also studied with the
batch equilibrium method. The chelating ion
-
exchange properties of this copolymer was studied for seven
Cu
2+
, Ni
2+,
Cd
2+
,Co
2+
, Hg
2+
, Zn
2+
, Pb
2+
and Fe
3+
metal ions. The study was carried ou
t over a wide pH range
and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe
3+
ions than for
Cu
2+
, Ni
2+,
Cd
2+
, Zn
2+
, Hg
2+
and Pb
2+
.
The difference in the selectivity of order of metal ions may be due to
the particle size
, high porosity nature, large surface area, nature of the material and metal ions.
The
surface morphology of the copolymer resin was examined by scanning electron microscopy and it
establishes the transition state between crystalline and amorphous phase.
