Studies on radiation grafting of hydrophilic monomer onto chitin for ion exchange application were examined . Over the past several years , chitin has been receiving increased attention for its application such as ion exchange . They are utilized scarcely because of problems associated with poor solubility, hidrophilicity and low reactivity. Graft copolymerization induced by irradiation is one of the methods for chitin modification in order to improve its properties such as hydrophilicity and reactivity. The aim of this research is to increasing the ability of chitin as ion exchange for heavy metal adsorbent.

1. IRRADIATION GRAFTING OF HYDROPHYLIC MONOMER
ONTO CHITIN FOR ION EXCHANGE APPLICATION
Gatot Trimulyadi Rekso
Center for Research and Development of Isotopes and Radiation Technology
Jl . Lebakbulus raya No 49, Jakarta 12240, INDONESIA
Fax 62 21 7691607, E-Mail : Gatot2811@yahoo.com
Abstract: Studies on radiation grafting of hydrophilic monomer onto chitin for ion exchange application were
examined . Over the past several years , chitin has been receiving increased attention for its application such as
ion exchange . They are utilized scarcely because of problems associated with poor solubility, hidrophilicity and
low reactivity. Graft copolymerization induced by irradiation is one of the methods for chitin modification in
order to improve its properties such as hydrophilicity and reactivity. The aim of this research is to increasing the
ability of chitin as ion exchange for heavy metal adsorbent. The hydrophilic monomers used were acrylic acid
and acryl amide. In the present experiment , the pre-radiation per oxidized method was employed . The
irradiation of sample was carried out in Co-60 gamma irradiation source at room temperature . The monomers
solutions acrylic acid or acryl amide than introduce into irradiated chitin and the graft polymerization was
carried out in nitrogen atmosphere. The presentation of grafting has been determined as a variation of monomer
concentration and temperature as a function of time of reaction. The grafted chitin obtained was washed and
dried in vacuum and the percentage of grafting was measured by gravimetric method . Measuring the capasity of
adsorption of grafted chitin to Cr, Cu and Hg metal ion was determined by using AAS and CV AAS. The result
shows that using acryl amide give percentage of grafting higher compare with acrylic acid. The presence of
monomer grafted onto chitin is demonstrated by FTIR spectrum with the appearing of carbonyl functional group.
Chitin grafted with acrylic acid give a higher rate of adsorption of metal ion Cr, Cu and Hg compare grafted with
acryl amide. The high rate of adsorption is for metal ion Hg it was found 294.3 mg/g for chit-g-Aac and 257.3
mg/g for Chit-g-Aam.
Keywords : Chitin, irradiation, grafting, ion exchange
INTRODUCTION. The adsorption behavior of chitin and its concerns
In order to solve the environmental problem due with various degree of deacetylization. This high
to industrial development, many factor have been adsorption capacity was ascribable primarily to its
studied . Generally, both solid and liquid industrial remarkable hydrophilicity in cooperation with the
waste can make seriously environmental problems. relatively high amino group content. It is indicate
that the importance of hydrophlicity and suggest
The liquid waste with the heavy metal content in the
that , in order to develop adsorbents of high capacity ,
large scale of production can be hazardous to
it is make indicate the importance of hydrophilicity
environmental conditions. Separation method of
essential to make chitin derivatives highly
heavy metal using ion exchange adsorbent to adsorb
hydrophylic and yet insoluble in water. Chitosan is
metal ion should be cheap, simple and industrial
natural polysaccharide and has the same skeleton
useful in waste treatment. The natural chelating
structure as cellulose, by a radiation modification
marine polymer chitin, poly(N-acetyl-D-
such as graft-co polymerization of hydrophilic
glucosamine) and its deacetylated derivative
monomer expected to improve its hidrophilicity.and
chitosan is useful for removing heavy metal ion
performance for application as an ion exchange
waste from discharge water . Chitin , the most
adsorbent. In the field of Radiation Process, free
abundant naturally is undoubtedly one of the most
radical formation is the key role of the modification
promising and attracting resources present in
technique. Graft modified of chitosan with
quantity. Among some interesting properties of
hydrophilic functional monomers was suitable
chitin , chelating ability arising from its characteristic
method to develop its as ion exchange adsorbent.
structure is especially noteworthy. Many researchers
have explored the feasibility of this approach. In this present study, the purpose of the
Kurita.K et.,all, conducted experiments with a experiments is to study graft-copolyimerization
number of heavy metals. reactions as well as to study the chemical and the
1

2. physical properties of grafted chitin. Hydrophilic
monomers such as acrylic acid, and acryl amide will
be employed for these experiments. The functional
group of graft –copolymers is expected to be useful
in the attaching test of metal ions.
of graft yield was calculated from the difference in
weight ;
II. EXPERIMENTAL.
Graft yield = ( Wg - Wo ) / Wo x 100 %
Material and Experiment: Chitin extracted from Where Wo and Wg are the weight before and after
prawn shell (Penaeus Monodon), it was got from grafting.
Muara Karang , North Jakarta. The were initially
washed by water and then dried at 800 C overnight
and conditioned at room temperature for 24 hr. Measuring off adsorption of metal ions by chitin
Acrylic acid monomer, and white crystalline powder and its modified : The experiment was done with
of acryl amide , obtained from E Merck , and other chitosan with degree of the deacetylization of 78,5 %
chemicals of reagent grade were used without and modified chitin were Chitin-g-Aac and Chitin-g-
purification. Aam with degree of grafting 32,4 % and 45,6 % and
modified chitosan were chitosan-g-Aac and Chitosan
Radiation Source : Gamma radiation source of
–g-Aam were got from deacetylated modified chitin.
Co-60, IRKA batch irradiator , with irradiation dose
Measuring the rate of adsorption about 100 mg of
rate about 9,0 kGy/hr was employed in these
powder material (chitin,chitosan and it’s
experiments. This radiation source is located at Pasar
modifications) equilibrated with 100 ml 0f solutions (
Jumat, Center for Research and Development of
HgSO4 , CuSO4.5 H2O, K2Cr2O7) 0,1 M, at pH 4,0
Isotopes and Radiation Technology, Jakarta,
and stirred for 60 min. The metal ion uptake
Indonesia.
concentrated after equilibrating were determined by
Grafting reaction: In the present experiment, the pre using AAS and for Hg(II) using CV-AAS.
irradiation graft co polymerization method was
employed. In this method a sample of chitin powder
of about 500 mg , was put into a glass tube, then III. RESULTS AND DISCUSSION
irradiated in air atmosphere at room temperature. A
monomer acryl amide solution was deairated by Evidence of grafting : The increase in weight of the
bubbling with nitrogen gas, then introduced into the extracted grafted sample, as compare with that the
pre irradiated sample and the graft polymerization original chitin and their FTIR spectra , was used as
was carried out in a nitrogen atmosphere at certain evidence of grafting. The FTIR spectra of chitin and
tempera-ture. The grafted chitin obtained was grafted chitin are shown in Fig 1. It can be seen that
washed toughly with aquadest and soaked overnight a band around at 1660 cm –1 arises from carbonyl
in aquadest, then subjected to sox let extraction with absorption of chitin and anew band appear at 3400
methanol for 8 hours to extract homopolymer. The cm-1 which correspond to the hydroxyl absorption of
grafted chitin then was dried in vacuum until they grafted chitin with acrylic acid and at 3500 cm -1 is
reached a constant weight at 500 C. The percentage asymmetric stretching of NH2 for grafted chitin with
acrylamide.
2

3. chitin powder and the solubility of the monomer ,
acryl amide monomer is good soluble in water-
methanol solvent .
By using acrylic acid or acryl amide concentration
above 30 % , high percentage of grafting was
obtained. However . the increase in percentage of
grafting is followed by increase of
homopolymerization, which is difficult to separate.
The result shows that the different on percentage
of grafting for reaction period of 3 hr and 4 hr is not
significant. It can be concluded that the optimum
monomer concentration is 30 % with 3 hr reaction
period.
100
Acrylic acid 10 %
Acrylic acid 20 %
) % g n t f ar g f o e g at n e c e P
80
Fig 1. The FTIR spectra of the original chitin
(
Acrylic acid 30 %
i
60 Acrylic acid 40 %
40
20
0
0 1 2 3 4 5 6
Reaction time (hr)
Fig 3. Effect of acrylic concentration on percentage of
grafting
160
10 % Acrylamide
140
Degree of grafting (% )
20 % Acrylamide
120
30 % Acrylamide
100
40 % Acrylamide
Fig 2. The FTIR spectra of chitin grafted with acrylic acid 80
monomer
60
Effect of monomer concentration and reaction time. 40
The effect of acrylic acid and acryl amide monomer
20
concentration on the percentage of grafting with
reaction period of 1 hr, 2 hr, 3 hr and 4 hr are 0
presented on Figure 2 and 3 . It can be seen that the
0 60 120 180 240 300
percentage of grafting is independent of the monomer
concentration. Grafting with acryl amide monomer Reaction time (min)
give higher yield percentage of grafting compare with
acrylic acid monomer. This may results in Fig 4. Effect of acrylamide concentration on percentage of
enhancement of the monomer diffusion into the grafting
3

4. From the figure 5 and 6, it is oblivious that the
degree of grafting is largely by the reaction
Grafting temperature . The reaction temperature temperature . The higher temperature the higher of
play a great role on the grafting process because this degree of grafting obtained. The reason is that the
influence on the diffusion of monomer into the increase in temperature improves the monomer
matrix polymer of chitin and also on the lifetime of diffusibility as well as the mobility of the monomer.
the peroxide radical in the preirradiated chitin. Figure It is recommended that the optimum reaction for this
5 and 6 shows the degree of grafting time curves for grafting system is 70 0 C more than that the increasing
the grafting of aqueous of 30 % acrylic acid of degree of grafting is not so much, there is a
monomer and 30 % of acrylamide at various nearly constant value.
temperature reaction
100
Temp 50 C The ion exchange adsorption of metals ions by
grafted chitin and its derivatives. The adsorption
P e rc e n ta g e o f g ra ftin g (% )
80 Temp 60 C
behavior of the resulting grafted chitin with acrylic
Temp 70 C
acid and acryl amide was examined in comparison
60 with the original chitin and chitosan. The results are
Temp 80 C illustrated in Table 1 .
40
Tabel 1. The capacity of adsorption of some
20 metal ions ( mg/gr) by chitin, chitosan and
grafted chitin/ chitosan
0
0 1 2 3 4 5 6
The capacity of adsorption
Time of reaction (hr) ( mg / g)
Fig 5. Effec of time reaction on percentage of grafting of Materials
acrylic acid at various temperature reaction Hg(II) Cr(VI) Cu(II)
200 Chitin 92,6 30,6 24,4
React. Temp 50 C
Chitosan 174,5 48,4 44,2
Degree of grafting (%)
160 React. Temp 60 C
Chitin-g-Aac 294,3 109,5 180,1
React. Temp 70 C
120
React. Temp 80 C
Chitin-g-Aam 257.3 94,8 154.6
80
Chitosan-g-Aac 488,9 318,5 362,8
Chitosan-g-AAm 464,2 325,8 398,2
40
0
0 60 120 180 240 300
These results clearly show that chitin modified as
Reaction time (min) chitin grafted acryl amide have higher capacity of
Fig 6. Effec of time reaction on percentage of grafting of adsorption for ion metal such Hg, Cr, and Cu. The
acrylamide at various temperature reaction highest one is for metal ion Hg both grafting with
acrylic acid or acryl amide. The chitin modified have
an excellent adsorption capacity due to the
advantageous location of -OH and –NH2 group in
4

5. the molecule of chitosan to form complex formation
and functional group of monomer act as ion
exchanger for ions metal.
IV. CONCLUSION
 Using acryl amide give percentage of
grafting higher compare with acrylic acid.
 The presence of monomer grafted onto
chitin is demonstrated by FTIR spectrum
with the appearing of carbonyl functional
group.
 The optimal condition of monomer acrylic
acid or acryl amide concentration was 30 %,
temperature 700 C and reaction period of 3
hours.
 Chitin grafted with acrylic acid give a higher
capacity of adsorption of metal ion Cr, Cu
and Hg compare grafted with acryl amide.
 The high rate of adsorption is for metal ion
Hg it was found 488,9 mg/g for chitosan-g-
Aac and 464,2 mg/g for Chitosan-g-Aam.
References
[1]. Goosen, M.F.A., Application of Chitin and
Chitosan, Technomic Publishing Company, Inc,
Lancaster, Pennsylvania, USA. 1997,.
[2] Chapiro, A., Radiation Chemistry of Polymeric
System. Willey Inter-science, New York, 1962.
[3] Kurita, K; Koyama,Y ; and Taniguchi, A.
Journal of Applied Polymer Science. 1986 , 31,
1169 – 1173
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