The aim of tiris resealch is io syathesize supra molecular compound in the
form of C-4-furylcalix[4]resorcinarene by using bagasse that abundantly available
as a starting material. The target compound is classified into a group of macro
cyclic nrolecules, such as crown etlier aiid cyciodextrin. These class of conipounds
have several active functional groups which are arranged in a unique molecular
geomeq/, which is shaped like a vase or crown making it possible to be used as a
host moiecuie fbr the cation, anion and neutral molecule. It is weii known that
some heavy metal cation such as Pb2* and Cd2* has its high toxicity that adversely
affect human health. Based on this phenomena, the study has been conducted to
synthesize an adsorbent for toxic metals Pb(ID and Cd(II) in the form of C4-
furylcalix[4]resorcinarene by using 2-furfiraldehyde based on bagasse. Synthesis
of C-4-fiir.vlcalix[4]resorcinarene has been done through several stages as follows:
(1) isolation of penthosan from bagasse by continuous extraction using tolueneethanol
solvent, (2) synthesis of 2-firfuraldehyde from penthosan by involving
process of h1'drolysis and dehydration in the presence of acid catalyst, (3)
purification of 2-furfuraldehyde via solvent extraction techniques and vacuum
distillation, ffid (4) acid catalyzed of condensation and cyclisation of 2-
frrfuraldehyde with resorcinol to produce C-4-furylcaiix[4jresorcinarcne. The
product of 2-furfuraldehyde was obtained in the yield of 11.47% which gave a
positive reaction to aniline acetate reagent, whereas C-4-
firrylcalix[4]resorcinarene was gained as dark brown solids n 73.25% wrth
melting point of 375-377 "C. Based on an analysis using IH-NMR spectrometer,
the compound of C-4-furylcalix[4]resorcinarene tend to exits in the crown
conformation.
The result indicated that C-4-furylca1ix[4]resorcinarene is a good host for
metal ions, where Cd(II) sorption capaerg was higher than that of Pb(II). Effect of
pH on batch experiments for the mentioned ions indicated that the optimum pH
for metal binding were 5 for both of lead(Il) and cadmium(Il). In order to
investigate the mechanism of adsorption, the l't-order, pseudo l't-order, and
pseudo 2nd-order kinetic models were used. The adsorption model of metal ions on
the resorcinarene followed pseudo second order of Ho & McKay expression. The
equiiibriurn adsorplion isoihcnn have becn analyzed by Langmuir aird Freunriiich
equations. Langmuir model had the higher correlation coefficient than that of
Freundlich model.
Keyword: baggase, 2-firfrua1<iehyde, C-4-firrylcalix[4jresorcinarene, crown
conformatio
