UNIVERSITI PUTRA MALAYSIA

SYNTHESIS AND CHARACTERIZATION OF NEW CHELATING RESINS CONTAINING THIOUREA AS THE FUNCTIONAL GROUP

MOHO SHABERI BIN MOHD AMIN

FSAS 2002 62

SYNTHESIS AND CHARACTERIZATION OF NEW CHELATING RESINS CONTAINING THIOUREA AS THE FUNCTIONAL GROUP

MOHO SHABERI BIN MOHD AMIN

MASTER OF SCIENCE

UNlVERSITI PUTRA MALAYSIA

2002

SYNTHESIS AND CHARACTERIZATION OF NEW CHELATING RESINS CONTAINING THIOUREA AS THE FUNCTIONAL GROUP

By

MOHD SHABERI BIN MOHD AMIN

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Requirements for tbe Degree of Master of Science

October 2002

Abstract of thesis presented to the Senate of Uruversiti Putra Malaysia in the fulfilment of requirement for the degree of Master of Science

SYNTHESIS AND CHARACTERIZATION OF NEW CHELATING RESINS CONTAINING THIOUREA AS THE FUNCTIONAL GROUP

By

MOHD SHABERI BIN MOHD AMIN

October 2002

Chairman: Sidik bin Silong, Ph.D.

Faculty: Science and Environmental Studies

11

A senes of chelating resins, derived from a macroreticular styrene-

divinylbenzene (2%) copolymer beads grafted with various spacer from propylene

groups (-CfiJ-CfiJ-CH2k (n=1, 2, 4) and containing thiourea as chelating function,

have been synthesized in a four-step reaction sequence. The steps began by the

reaction of diethyl malonate with a spacer (ethylene groups), followed with the

attachment of the arm group to the polymer. The polymer was then hydrolyzed and

converted to its polychloride acid derivatives and followed by the attachment of the

thiourea functional group to produce the new chelating resins.

The reaction of diethyl malonate with the spacer has been monitored by using

nuclear magnetic. resonance analysis. Meanwhile, the presence of all the functional

1II

groups has been deduced by infrared spectroscopy. Due to the insolubility of the

backbone resin, the presence or absence of certain bands expected for particular

functional groups in their infrared spectra was used to monitor the success of the

grafting process. The e, H, Nand S elemental analyses data were used to estimate

the degree of conversion in each and every step of the reactions and the surface

morphology was studied by using scanning electron microscopy.

The complexation behavior of these resins was investigated towards Hg(II),

eu(II) and Pb(II) ions in aqueous solutions by the batch equilibration technique. The

influence of pH on adsorption capacity was also examined. The adsorption values for

metal ions' intake followed the order Hg(n) > eu(n) > Pb(II). Polymers can be

regenerated by washing with the mixture solution of hydrochloric acid and an

aqueous solution of thiourea by using the column method.

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

PENYEDIAAN DAN PENCIRIAN RESIN PENGKELAT BARU YANG MENGANDUNGI KUMPULAN BERFUNGSI TIOUREA

Oleh

MOHD SHABERI BIN MOHD AMIN

Oktober 2002

Pengerusi: Sidik bin Silong, Ph.D.

Fakulti: Sains dan Pengajian Alam Sekitar

IV

Satu siri resin pengkelatan diterbitkan dari manik-manik rangkaian makro ko-

polimer stirena-divinilbenzena (2 %) yang tercangkuk dengan bahagian lengan

mengandungi kumpulan berfungsi tiourea menerusi beberapa peruang propilena (-

CHrCH2-CHZ)n (n = 1, 2, 4), telah disediakan melalui empat langkah tindak balas.

Dimulai dengan tindak balas dietilmalanot dengan peruang (kumpulan etilena) yang

kemudiannya dirangkaikan kepada polimer. Seterusoya polimer terubahsuai itu

dihidrolisis dan ditukarkan menjadi asid poliklorida terbitan, serta diikuti deogan

memasukkan kumpulan berfungsi tiourea bagi mendapatkan resin pengkelat barn.

Tindak balas diantara dietilmalanot dengan peruang telah ditentukan

menggunakan analisis resonan magnetik nuklear. Manakala kehadiran semua

v

kumpulan berfungsi ditentukan melalui spektroskopi infra-merah kerana ketidak

larutan rangka asas resin. Kejayaan setiap langkah tindak balas penyangkukan

ditentukan berdasarkan kepada kehadiran atau ketidakhadiran jalur-jalur serapan

tertentu bagi kumpulan-kumpulan berfungsi berkaitan. Analisis unsur e, H, N dan S

dilakukan bagi menganggarkan kadar pengubahan bagi setiap langkah tindak balas,

manakala morfologi permukaan dikaji menggunakan mikroskopi pengimbasan

elektron.

Pembentukan komplek resin ini terhadap ion-ion Hg(II), eU(Il) dan Pb(ll)

telah dikaji dalam larutan akuas menggunakan teknik keseimbangan pukal. Kesan

pH terhadap kapasiti penjerapan resin juga dikaji. Nilai jerapan resin ini terhadap ion

logam adalah mengikut urutan Hg(II) > eu(II) > Pb(II). Polimer ini boleh dijana

semula selepas dibilas menggunakan campuran Iarutan asid hidroklorida dan larutan

akuas tiourea melalui keadah turus.

VI

ACKNOWLEDGEMENTS

All praise to Allah S. W. T. who has showered me with kindness and affection

during the course of my study that I cannot adequately thank for. His endless grace

and love have provided me with the strength to finish this study.

I would like also to express my deepest and warmest sense of thanks and

appreciation to my honorable project supervisor, Dr. Sidik bin Silong for his

invaluable assistance, constructive criticisms and inspiring guidance. But most of all

for his most understanding and patience which has been a great favour on my behalf,

I am also grateful to other members of the supervisory committee (Assoc. Prof Dr.

Md. lelas bin Haron, Prof Dr. Wan Md. lin bin Wan Yunus and Assoc. Prof. Dr.

Mohd. laki bin Abd. Rahman).

My sincere thanks also go to all lecturers in Department of Chemistry and I

would like to acknowledge the assistance provided by the Department of Chemistry

and staff of this department, especially to Mr. lainal Zahari, Mr. Zainal Kassim, Mr.

Kamal Margona and Mrs. Rosnani for their favourable help_ Thank also go to the

Ministry of Science, Technology and Environment, Government of Malaysia for

financial assistant. This research was funded by an IRPA Grant No: 09-02-04-0057.

vii

Finally, I would like to express my deepest gratitude to my family and friends

for their endless encouragement, patience and sacrifices, which had helped me in

understanding and completing this research project.

VI11

I certify that an Examination Committee met on 28th October 2002 to conduct the final examination of Mohd Shaberi bin Mohd Amin on his Master of Science thesis entitled "Synthesis and Characterization of New Chelating Resins Containing Thiourea as the Functional Group" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The Committee recommends that the candidate be awarded the relevant degree. The members of the Examination Committee are as follows:

MANSOR BIN AHMAD, Ph.D.

Associate Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia (Chairman)

SIDIK BIN SILONG, Ph.D.

Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

MD. JELAS BIN HARON, Ph.D.

Associate Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

WAN MD. ZIN BIN WAN YUNUS, Ph.D.

Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

MOHD. ZAKI BIN ADD. RAHMAN, Ph.D.

Associate Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

_�J ..... SHER MOHAMAD RAMADILI, Ph.D. Professor/ Deputy Dean School of Graduate Studies, Universiti Putra Malaysia Date: ·2 4 S�:: 2002

IX

This thesis submitted to the Senate of Universiti Putra Malaysia has been accepted as partial fulfilment of the requirement for the degree of Master of Science. The members of the Supervisory Committee are as follows:

SIDIK BIN SILONG, Ph.D.

Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Chairman)

MD. JELAS BIN HARON, Ph.D.

Associate Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

WAN MD. ZIN BIN WAN YUNUS, Ph.D. Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

MOHD. ZAKI BIN ABD. RAHMAN, Ph.D.

Associate Professor Faculty of Science and Environmental Studies, Universiti Putra Malaysia. (Member)

AINI IDERIS, Ph.D. ProfessorlDean School of Graduate Studies, Universiti Putra Malaysia

Date: 1:3 FEB 2nm

x

DECLARA TION

I hereby declare that the thesis is based on my original work expect for quotations and citations, which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

MOUD SlfABERI BIN MOHD AM IN

Date: �� / J � / �oo'.t

Xl

TABLE OF CONTENTS

Page

ABSTRACT Il ABSTRAK ACKNOWLEDGEMffiNTS APPROVAL SHEETS DECLARATION

iv VI Vl1l X

TABLE OF CONTENTS LIST OF TABLES

Xl XIV XV XVlll

LIST OF FIGURES LIST OF ABBREVATIONS AND SYMBOLS

CHAPTER

I INTRODUCTION 1.1 Heavy Metal 1 1.2 Toxicity 4

1.2.1 Copper 4 1.2.2 Lead 5 1.2.3 Mercury 8

1.3 Chelating Resin 11 1.4 Objectives 12

n L ITERATURE REVIEW

2.1 Cation Exchangers 13 2.2 Anion Exchangers 16 2.3 Crosslinked Polystyrene Resins 17

2.3.1 Physical Nature of the Crosslinked Polymers 18 2.3.2 Solvent Swellable Resin Beads 18 2.3.3 Rigid Macroporous or Macroreticular Beads 20 2.3.4 Popcorn Polymers 21

2.4 Synthesis of Complexing and Chelating Ion-exchange Resins 21 2.5 Types and Synthesis of Polymeric Matrices 22 2.6 Synthesis of Chelating Resins based from Styrene-divinylbenzene 26 2.7 Thiourea 33

ill EXPERIMENTAL

xii

3.1 Materials 35 3.2 General Approach 36 3.3 Purification of Die thy 1 Malonate 4 1 3.4 Preparation of the Reagents 41 3.5 Synthesis of the Resins 42

3.5.1 Preparation of Alkylmalonic Ester. [Diethy12-(3-hydroxypropyl) malonate ( n = 1), DiethyI2-(6-hydroxyhexyl) malonate ( n = 2) and Diethyl 2-(12-hydroxydodecyl) malonate ( n = 4)] 42

3.5.2 Preparation of Alkylmalonic Ester Grafted Chloromethylated Polystyrene Beads ( PSR-ET) 43

3.5.3 Hydrolysis of Alkylmalonic Ester Grafted Chloromethylated Polystyrene Beads (PSR-OH) 44

3.5.4 Modification of the Polycarboxylic Acid to the New Polymeric Resin (PSR-SH) 44

3.6 Characterization of Reaction Products 45 3.7 Resin Characterization 46

3.7.1 Stability of the Resins 46 3.7.2 Water Regain 46

3.8 Batch Method 47 3.8.1 Resins Capacity for Metal Ions 47 3.8.2 Isotherm Study 48

3.9 Column Method 48 3.9. 1 Extraction and Elution of Metallons 48 3.9.2 Separation of Metal Ions 49 3.9.3 Breakthrough Experiment 49

IV RESULTS AND DISCUSSION

4. 1 Synthesis of the Resin 4.2 Characterization of the Reaction Products

4.2.1 Nuclear Magnetic Resonance 4.2.2 Infrared Spectroscopy 4.2.3 Elemental Analysis 4.2.4 Scanning Electron Microscopy

4.3 Resins Characterization 4.3.1 Stability of the Resins 4.3.2 Water Regain

4.4 Batch Method Study 4.4.1 Sorption of Metal Ion

50 52 52 60 71 74 78 78 78 79 79

4.4.2 Isothenn Study 4.5 Column Method Study

4.5.1 Extraction 4.5.2 Elution of Metal Ions 4.5.3 Separation of Metal Ions 5.3.5 Breakthrough Study

V CONCLUSION AND RECOMM ENDAT ION

5.1 Conclusion 5.2 Recommendation for Future Study

REFERENCES

APPENDICES

Appendix A Appendix B AppendixC

BIODATA OF THE AUTHOR

Xlll

86 88 88 90 95 100

102 104

106

115 123 128

133

XlV

L IST OF TABLES

Table Page

1.1 Substances Present in Industrial Effluents (Lester, 1987) 2

2.1 Cation and Anion Exchangers 17

4.1 IR Characteristic Bands ( em-I) of Resins 70

4.2 Elemental Analysis Data 71

4.3a The capacity of Cu( II) adsorbed at different pH values using resins with different length of spacer 84

4.3b The capacity ofPb( II) adsorbed at different pH values using resins with different length of spacer 8S

4.3c The capacity of Hg(U) adsorbed at different pH values using resins with different length of spacer 8S

4.4 Maximum recovery of metal ions using resins with different length of spacers 95

xv

LIST OF FIGURES

Figure Page

2.1 Condensation Polymers 24

2.2 Addition Polymers 25

2.3 Chemical Structure of Resin Synthesized by Lezzi et at. (1994) 27

2.4 Chemical Structure of Resin Synthesized by Akerkar et at. (1998) 28

2.5 Chemical Structure of Resin Synthesized by Kapil and Rao (1996) 29

2.6 Chemical Structure of Resin Synthesized by Ahuja et at. (1996) 30

2.7 Chemical Structure of Resin Synthesized by Suzuki and Yokoyama (1983 )31

2.8 Chemical Structure of Resin Synthesized of Drago et al. (1980) 32

2.9 Chemical Structure of Resin Synthesized of Kumar et al. (2000) 32

4.1 Synthesis Pathway 51

4.2a IH NMR Spectrum of Die thy I Malonate 53

4.2b IH NMR Spectrum ofDiethyI2-(3-Hydroxypropyl) Malonate 54

4.2c IH NMR Spectrum ofDiethyI2-(6-Hydroxyhexyl) Malonate 57

4.2d IH NMR Spectrum ofDiethyI2-(12-Hydroxydodecyl) Malonate 58

4.3a Chemical Structure ofDiethyI2-(3-Hydroxypropyl) Malonate 55

4.3b Chemical Structure ofDiethyI2-(6-Hydroxyhexyl) Malonate 56

4.3c Chemical Structure ofDiethyI2-(12-Hydroxydodecyl) Malonate 59

4.4a IR Spectrum of Diethyl Malonate Using NaCI Window 61

xvi

4.4b IR Spectrum ofDiethyI2-(3-Hydroxypropyl) Malonate Using NaCI Window 62

4.4c IR Spectrum ofChloromethylated Polystyrene Beads (PSR-CL) in KBr Pellet 65

4.4d IR Spectrum ofDiethyI2-(3-Hydroxypropyl) Malonate Grafted Chloromethylated Polystyrene Beads (PSR-ET) in KBr Pellet 66

4.4e IR Spectrum of Hydrolysis Diethyl 2-(3-Hydroxypropyl) Malonate Grafted Chloromethylated Polystyrene Beads (PSR-OH) in KBr Pellet 67

4.4f IR Spectrum of New Polymeric Resin (PSR-SH) in KBr Pellet 68

4.5 Schematic Diagram of Suggested Beads Structure 73

4.6a Scanning Electron Microscopy Image of Chloromethylated Polystyrene Beads (PSR-CL) 76

4.6b Scanning Electron Microscopy Image ofDiethyI2-(3-Hydroxypropyl) Malonate Grafted Chloromethylated Polystyrene Beads (PSR-ET) 76

4.6c Scanning Electron Microscopy Image of Hydrolysis Diethyl 2-(3-Hydroxypropyl) Malonate Grafted Chloromethylated

Polystyrene Beads (PSR-OH) 77

4.6d Scanning Electron Microscopy Image of New Polymeric Resin 77

4.7a Percentage sorption of Cu(II) ion at various pH using resin with different length of spacers 80

4.7b Percentage sorption ofPb( II) ion at various pH using resin with different length of spacers 81

4.7c Percentage sorption ofHg(ll) ion at various pH using resin with different length of spacers 82

4.8a Equilibrium Isotherm for the Sorption of Cu(n) Ion 87

4.8b Langmuir Isotherm for the Sorption of Cu(n) Ion 88

4.9 Suggested Complex Formation 89

XVIi

4.10a Elution of Cu(II) ion with PSR-SH ( n=l) 92

4.10b Elution ofPb(II) ion with PSR-SH ( n=l) 93

4.10c Elution of Hg( II) ion with PSR-SH ( n=l) 94

4.1 1a Separation of Cu(II) - Hg(II) by resin n = 1 97

4. 11b Separation ofPb(II) - Hg( II) by resin n = 1 98

4. 1 1c Separation of Cu(II) - Pb(II) by resin n = 1 99

4.12 Breakthrough Curves 100

xviii

LIST OF SYMBOLS AND ABBREVIATIONS

ppm Part per million

DVB Divinylbenzene

PSR Polystyrene resin

v Stretching vibration

8 Bending vibration

Os Scissor vibration

op Rocking vibration

Ot Twisting vibration

Ow Wagging vibration

Co Initial concentration

C Equilibrium concentrations

WR Weight of dry resin

Q Capacity

V-- Polymeric chain

1 .1 Heavy Metal

CHAPTER I

INTRODUCTION

The problem of heavy metal contamination in waterbodies is widespread

and becoming more acute, threatening an ever increasing portion of global

population. Such an environmental pollution is mainly due to rapid

industrialization together with the increase in modem method of agriculture

especially in the developing countries.

Water pollution is mainly caused by untreated released of effluent by

industries such as plating, electroplating, leather, textile and battery manufacturer.

(Some of the sources where heavy metals could be found are listed in Table 1.1).

Among the most common heavy metals found in industrial wastewater are ell, Ni,

Zn, Cr, Hg and Pb. Accumulation of these metal ions in trace quantity in human

body cause physiological and neurological disorder. However, at a higher

concentration they are very toxic and cause severe health problem, which may

cause death. Therefore, heavy metal ion concentration in wastewater must be

controlled and reduce to a low level.

2

Chemical precipitation, ion exchange, reverse osmosis, solvent extraction

and ultrafiltration could achieve removal of metal ions from wastewater.

Table 1.1: Substances Present in Industrial Effiuents (Lester, 1987).

Substances Usage in Industries

Arsenic Semi-conductors & photoconductors, agrochemical such as insecticides.

Aluminum Construction of building and transport, aluminum foils.

Cadmium Electroplating & coating industry pigment for paint.

Chromium Machinery-construction industry alloys in transport & heater elements.

Copper Electronics, plating, brass & other alloys, fertilizer, rayon manufacture.

Lead Battery manufacture, anti-knock additions for gasoline, piping.

Mercury Instrumentation for measurement and control, amalgam in dentistry.

Nickel Alloys, electroplating, pigments, catalysts, electrical contacts & batteries.

Silver Photographic products plated silverware, jewelry & battery manufacture.

Zinc Brass & bronze alloys for galvanizatio� cosmetics & pharmaceuticals.

Shkinev et al. (1989) reported a new method for determination of trace

heavy metal in water by atomic absorption spectrometry after preconcentration by

liquid-phase polymer-based retention The method has been applied to the

determination of NL Cu, Zn, Hg and Cd in drinking and river water with

poly(ethyleneimine) and its thiourea derivative as complexing polymer. The

metals were determined in aqueous concentrate after a 250-fold preconcentration

by 2% polymer solution at pH 7.

3

laporozhets et al. (1999) obtained the modified sorbents with dithizone

and zinc thizonate adsorbed on the silica surface. Adsorption of heavy metal ions

from aqueous solutions onto loaded silica was studied. Color scales for Ag(I),

Hg(II) and Pb(U) visual test detection were developed. The modified silica gels

were established to be applicable to the quantitative determination of these metal

ions in buttermilk, natural, mineral and wastewater.

A method for the determination of Cu, In, Fe, Ni and Cd by flame atomic

absorption spectrophotometry (F-AAS) after preconcentrating on a column

containing Escherichia coli immobilized on sepiolite has been developed by Bag

et al. (2000). Optimum pH values, amount of adsorbent, elution solution and flow

rate have been obtained for the elements studied. The effect of interfering ions on

the recovery of the analytes has also been investigated. Recoveries ofCu, Zn, Fe,

Ni and Cd by E. coli immobilized on sepiolite were 99.1 ± 0.6, 98.2 ± 0.6, 98.1 ±

0.5, 97.2 ± 0.8 and 98.2 ± 0.4 % (at 95 % confidence level), respectively. The

adsorption capacity of E. coli immobilized on sepiolite was found to be 0.148,

0.064,0.098,0.134 and 0.088 mmol/g for Cu, In, Fe, Ni and Cd, respectively.

Tiravanti et al. (1997) investigated the conservative technologies to utilize

natural and synthetic reactive polymers for selective metal removal, recovery and

reuse. Examples refer to the treatment of industrial wastes containing silver,

cadmium, mercury, chromium, iron and aluminum by different innovative

processes. A precipitation process was described, namely Metals Extration by

Xanthate Insolubilization and Chemical Oxidation (MEXICO), using agricultural

4

raw materials to prepare starch or cellulose xanthates as precipitating agents for

metals.

1.2 Toxicity

1.2.1 Copper

Copper is an essential element used in process of blood formation and iron

utilization, with a human daily requirement of 0.03 mglkg for adults. The main

intake is normally through the diet and water consumption. Copper occurs in

aqueous solution in oxidation states of (I) and (II), but former is unstable above

equilibrium concentration of 10-2 M and in aerated natural waters it is generally

oxidized to Cu(II).

Copper is absorbed through the intestinal tract (40 to 70 %) and absorption

varies with intake. Its half-life in human is 80 days and total body burden is 75 to

150 mg. Once absorbed, copper is transported in the blood and stored normally in

muscle, liver and brain tissue. In cases of acute toxicity, copper is found in the

brain, liver, stomach, hair roots and urine. Symptoms of acute toxicity are gastric

ulcers, hemolysis, jaundice, hepatic necrosis and renal damage. Chronic toxicity

in man is found infrequently but has been reported to cause "pink disease" in

infant ingesting copper-contaminated water at concentrations of 0.8 mg/I.

Elevated levels of copper are associated with disorders such as biliary atresia and

cirrhosis in children, Hoadkin's disease, leukemia and atherosclerosis.

5

Microamount of copper takes part in oxidization inside the human body

and is relative to some illnesses of the body, so it is important to determine

microamount of copper. Ma et al. (1999) synthesized a new sensitive reagent

based on the new long-chain saturated fatty hydrocarbon substituting group

compound, N-undecyl-N -(sodium p-aminobenzenesulfonate)-thiourea (UPT).

According to the studies on its analytical performance, it is found that this reagent

can be used to identify Cu2+ and determine microamounts of copper (E300A nm =

2.39 X 105 I morl em-I) in aqueous solution. These new methods are simple and

convenient and can provide satisfactory results on samples.

Ferreira et al. (2000) proposed a procedure for the separation and

preconcentration of trace amounts of copper in natural water samples. It is based

on the adsorption of copper(ll) ions onto a column of Amberlite XAD-2 resin

loaded with calmagite reagent. This way amounts of copper within the range

from 0.0125 to 25.0 J,lg, in a sample volume of 25 to 250 ml, and pH from 3.7 to

10.0 was concentrated as camagite complex in a column of 0.50 g of Amberlite

XAD-2 resin. Detection and determination limits of the proposed procedure for

250 ml sample volume were 0.15 and O. 50 J,lg r\ respectively.

1.2.2 Lead

Lead (Pb) is one of the oldest metals known to man and, since medieval

times, has been used in piping, building materials, soldering, paints, ammunition

and castings. More recently, lead has been used mainly in storage batteries (35