UNIVERSITI PUTRA MALAYSIA

PREPARATION AND CHARACTERIZATION OF POLY(BUTYLENE ADIPATE-CO-TEREPHTALATE) /OIL PALM EMPTY FRUIT BUNCH

FIBER BIOCOMPOSITES

SAMIRA SIYAMAK

FS 2011 94

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PREPARATION AND CHARACTERIZATION OF POLY(BUTYLENE ADIPATE-CO-TEREPHTALATE) /OIL PALM EMPTY FRUIT BUNCH FIBER

BIOCOMPOSITES

By

SAMIRA SIYAMAK

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

February 2011

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the requirements for the degree of Master of Science

PREPARATION AND CHARACTERIZATION OF POLY(BUTYLENE ADIPATE-CO-TEREPHTALATE)/OIL PALM EMPTY FRUIT BUNCH FIBER

BIOCOMPOSITES

By

SAMIRA SIYAMAK

February 2011

Chair: Nor Azowa Ibrahim, PhD

Faculty: Science

During the last years, the interest in renewable and biodegradable materials has

tremendously increased in the global community. The global market for renewable and

biodegradable materials increases immensely due to societal awareness of the climate

situation and the problems arise from thermoplastics. In this research, the oil palm empty

fruit bunch (EFB) fiber was used as an interesting source of lignocellulosic filler for

preparation of the cost effective and biodegradable composites. The aliphatic aromatic

co-polyester poly(butylene adipate-co-terephthalate) PBAT (EcoflexTM), a fully

biodegradable thermoplastic polymer was used as matrix. The aim of this research is to

fabricate a new class of biocomposite based on PBAT/EFB fiber and to improve the new

biocomposites’ performance by chemical modification using succinic anhydride (SAH)

as coupling agent in presence and absence of dicumyl peroxide (DCP) and benzoyl

peroxide (BPO) as initiator. For the composite preparation, several blends were prepared

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at different contents of filler and matrix using melt blending technique. The specimens

for mechanical tests were prepared based on ASTM standards. The effects of fiber

loading and coupling agent loading on thermal properties of biodegradable polymer

composites were evaluated using thermal gravimetric analysis (TGA) and dynamic

mechanical analysis (DMA). TGA was used to evaluate composite decomposition and

stability whilst DMA was utilized to evaluate parameters such as the glass transition

temperature, Tg, storage modulus, E' and loss modulus, E". Scanning Electron

Microscopy (SEM) was used for morphological studies. The chemical structure of new

biocomposite was also analyzed using Fourier Transform Infrared (FTIR) Spectroscopy

technique. The water absorption test was used for composite moisture absorption

determination and the burial test was used to biodegradation studies.

The PBAT biocomposite reinforced with 40 (wt%) of EFB fiber showed the best

mechanical properties compared to the other PBAT/EFB fiber biocomposites.

Biocomposites treatment with 4 (wt%) of succinic anhydride (SAH) and 1 (wt%) of

DCP improved both tensile and flexural strength as well as tensile and flexural modulus,

whereas the biocomposites’ impact strength improvement was only marginal. The FTIR

analyses proved the mechanical test results by presenting the evidences of successful

esterification using SAH/DCP in biocomposites’ spectra. The SEM micrograph of the

tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using

SAH. The TGA results showed that chemical modification using SAH/DCP improved

the thermal stability of PBAT/EFB biocomposite. The DMA results showed the

improvements of storage modulus as well as loss modulus and Tg of new composite

modified by SAH. The water absorption test results indicated a decrease in moisture

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absorption trend of new biocomposite affected by (SAH) coupling agent compared to

the untreated biocomposite. The biodegradation test observations showed a moderate

increase in biological resistance of the modified biocomposites compare to the

unmodified one.

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

PEMBUATAN DAN KARAKTERISASI POLI(BUTILENA ADIPAT-KOTEREFTALAT)/ MINYAKSAWIT BIOKOMPOSIT IKATAN BUAH SERAT

KOSONG

Oleh

SAMIRA SIYAMAK

Februari 2011

Pengerusi: Nor Azowa Ibrahim, PhD

Fakulti: Sains

Selama tahun terakhir, bunga di bahan terbarukan dan ramah lingkungan telah sangat

meningkat dalam komuniti global. Pasar global untuk bahan terbarukan dan ramah

lingkungan sangat meningkat kerana kesedaran masyarakat tentang situasi iklim dan

masalah-masalah yang timbul dari termoplastik. Dalam kajian ini, kelapa sawit tandan

buah kosong (TKS) serat digunakan sebagai sumber lignoselulosa menarik filler

penyusunan kos komposit berkesan dan biodegradable. The alifatik aromatik co-

poliester (polibutylene adipat-co-terephthalate) PBAT (EcoflexTM), sebuah polimer

termoplastik biodegradable sepenuhnya digunakan sebagai matriks. Tujuan dari

penelitian ini adalah untuk membuat kelas baru biokomposit berdasarkan PBAT / serat

TKS dan untuk meningkatkan prestasi biokomposit baru 'dengan pengubahsuaian kimia

menggunakan esternya suksinat (SAH) sebagai agen kopling dalam keberadaan dan

ketiadaan dicumyl peroksida (DCP) dan benzoil. peroksida (BPO) sebagai

inisiator. Untuk penyusunan komposit, beberapa campuran kandungan yang berbeza

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disiapkan di filler dan matriks menggunakan teknik pencampuran mencair. Spesimen

untuk uji mekanikal disusun berdasarkan standard ASTM. Kesan daripada serat dan

loading loading kopling agen terhadap sifat terma komposit polimer biodegradable

dievaluasi menggunakan analisis gravimetri termo (TGA) dan analisis mekanik dinamik

(DMA). TGA digunakan untuk menilai dekomposisi komposit dan kestabilan sementara

DMA ini digunakan untuk menilai parameter seperti suhu peralihan kaca, T, simpanan

modulus, modulus E' dan rugi, E" Scanning Elektron. Microscopy (SEM) digunakan

untuk kajian morfologi. Thestruktur kimia biokomposit baru ini juga dianalisis

menggunakan Fourier Transform Infrared (FTIR) Spektroskopi teknik. Ujian

penyerapan air digunakan untuk penyerapan kelembapan penentuan komposit dan uji

pengebumian itu digunakan untuk kajian biodegradasi.

The biokomposit PBAT diperkuatkan dengan 40 (% wt) serat TKS menunjukkan sifat

mekanik terbaik berbanding / lain PBAT biokomposit serat TKS. perubatan biokomposit

dengan 4 (% wt) dari esternya suksinat (SAH) dan 1 (% wt) dari DCP ditingkatkan baik

kekuatan tarik dan lentur serta modulus tarik dan lentur, sedangkan kesan peningkatan

kekuatan biokomposit 'hanya marjinal. Analisis FTIR membuktikan keputusan ujian

mekanik dengan menunjukkan bukti-bukti sukses pengesteran menggunakan SAH /

DCP pada spektrum biokomposit. The mikrograf SEM dari paras patah tarik

menunjukkan peningkatan adhesi serat-matriks selepas menggunakan SAH. TGA

Keputusan kajian menunjukkan bahawa pengubahsuaian kimia menggunakan SAH /

DCP meningkatkan kestabilan terma PBAT / biokomposit TKS.Keputusan DMA

menunjukkan perbaikan modulus simpanan serta modulus kehilangan dan Tg komposit

baru diubahsuai oleh SAH. Keputusan uji penyerapan air menunjukkan trend penurunan

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penyerapan kelembapan biokomposit baru dipengaruhi oleh (SAH) coupling agent

dibandingkan dengan biokomposit tidak dirawat. Pemerhatian uji biodegradasi

menunjukkan peningkatan sederhana dalam perlawanan biologi dari biokomposit buat

kali terakhir berbanding dengan yang tidak diubahsuai pertama.

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ACKNOLEDGEMENTS

I would like to take this opportunity o express my utmost gratitude to the chairman of

my supervisory committee Dr. Nor Azowa Ibrahim, for her invaluable guidance and

advices through this research. Sincere thanks are due to Prof. Dato' Dr. Wan Md Zin

Wan Yunus and Assoc. Prof. Dr. Mohamad Zaki Ab Rahman for their kind support and

valuable guidance.

Special thanks also to all the faculty staff members that have helped me throughout this

period. It is a pleasure to acknowledge my brother Ali Siyamak for his kind support and

encouragements. My sincerely appreciation also goes to my parents for their supports,

understanding and sacrifices. Finally, I would like to dedicate this work to my beloved

son, Mehryar, who is my every day’s sun.

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I certify that an Examination Committee has met on 23 February 2011 to conduct the final examination of Samira Siyamak on her Master of Science thesis entitled “Preparation and characterization of Poly(Butylene Adipate-co-Terephthalate)/Oil Palm Empty Fruit Bunch Fiber Biocomposites“, in accordance with Universiti Pertanian Malaysia (higher degree) act 1980 and Universiti Pertanian Malaysia (higher degree) Regulations 1981. The committee recommends that the student be awarded the relevant degree. Members of the examination committee were as follows:

Prof. Madya Dr. Sidik Silong Faculty of Science Universiti Putra Malaysia (Chairman)

Prof. Madya Dr. Mansor Ahmad Faculty of Science Universiti Putra Malaysia (Internal Examiner)

Prof. Madya Dr. Abdul Halim Abdullah Faculty of Science Universiti Putra Malaysia (Internal Examiner)

Prof. Madya Dr. Rusli Daik School of Chemical Science and Technology Faculty of Science and Technology Universiti Kebangsaan Malaysia 43600 UKM-Bangi Selangor (External Examiner)

_________________________________ HASANAH MOHD.GHAZALI, PhD Professor and deputy dean School of graduate studies University Putra Malaysia Date:

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This thesis was submitted to the senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirements for the degree of Master of Science. The members of the supervisory committee were as follows:

Nor Azowa Ibrahim, PhD Senior Lecturer Faculty of Science Universiti Putra Malaysia (Chairman)

Wan Md Zin Wan Yunus, PhD Professor Faculty of Science Universiti Putra Malaysia (Member)

Mohamad Zaki AB Rahman, PhD Associate Professor Faculty of Science Universiti Putra Malaysia (Member)

______________________________

HASANAH MOHD. GHAZALI, PhD Professor and Dean

School of Graduate Studies Universiti Putra Malaysia

Date:

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DECLARATION

I declare that the thesis is my original work except for quotations and citation, which have been duly, acknowledge. I also declare that it has not been previously, and is not currently, submitted for any other degree at universiti Putra Malaysia or at any other institution.

___________________ SAMIRA SIYAMAK

Date: 23 February 2011

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TABLE OF CONTENTS Page ABSTRACT ii ABSTRAK v ACKNOWLEDGEMENTS viii APPROVAL ix DECLARATION xi TABLE OF CONTENTS xii LIST OF TABLES xv LIST OF FIGURES xvii LIST OF SCHEMES xxi LIST OF ABBREVIATIONS xxii CHAPTER 1 INTRODUCTION 1�

1.1 Back Ground of Study 1�1.1.1 Biodegradable Synthetic Thermoplastic Polymer (PBAT) 3�1.1.2 Natural Fiber (Oil Palm Empty Fruit Bunch Fiber) 4�

1.2 Significance of Study 6�1.3 Objectives of Research 8�

2 LITERATURE REVIEW �

2.1 Natural Fibers 9�2.1.1 Natural Fiber: Source and Classification 9�2.1.2 Oil Palm Empty Fruit Bunch Fiber (EFB) 11�2.1.3 Issues Regarding the Use of Natural Fiber in Composites 16�

2.2 Biodegradable Polymers 20�2.2.1 Biodegradable Thermoplastics: Source and Classification 21�2.2.2 Poly Butylene Adipate-co-Terephthalate (PBAT) 23�

2.3 Natural Fiber/Biodegradable Thermoplastic Composites (Green Composites) 28�

2.3.1 Oil Palm EFB Fiber Filled Bio Thermoplastic Composite 31�2.3.2 PBAT/Natural Fiber Reinforced Composite 32�

2.4 Methods to Improve the Properties of Biocomposites 34�2.4.1 Coupling Agents: Classification and Actions 37�2.4.2 Modification of Natural Fiber and Biopolymer 40�

2.5 Mechanical Properties of Green Composite 48�2.6 Thermal Properties of Green Composites 50�2.7 Biodegradation of Green Composites 51�

3 MATERIALS AND METHODOLOGY 53�

3.1 Materials 53�3.2 Methods 55�

3.2.1 Preparation of Oil Palm Empty Fruit Bunch Fiber 56�

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3.2.2 Preparation of New Biodegradable Composites 58�3.3 Fourier Transform Infrared Spectroscopy (FTIR) 63�3.4 Mechanical Properties of Biodegradable Composites 63�

3.4.1 Tensile Test 63�3.4.3 Flexural Test 63�3.4.2 Impact Test 65�

3.5 Thermal Analysis of Biodegradable Composites 65�3.5.1 Thermal Gravimetric Analysis (TGA) 66�3.5.2 Dynamic Mechanical Analysis (DMA) 66�

3.6 Surface Morphology Study 67�3.7 Water Absorption Study 68�3.8 Biodegradation Study 68�

4 RESULTS AND DISCUSSIONS 70�

4.1 Effects of Fiber Loading on Mechanical Properties of PBAT/EFB Composites 70�

4.1.1 Tensile Properties 70�4.1.2 Flexural Properties 73�4.1.3 Impact Properties 76�

4.2 Effects of Fiber Modification on Mechanical Properties of PBAT/EFB Fiber Composites 778�

4.2.1 Effect of Fiber Modification Using SAH and Initiator on Tensile Properties of PBAT/EFB Biocomposites 79�4.2.2 Effect of Fiber Modification Using SAH and Initiator on Flexural Properties of PBAT/EFB Biocomposites 86�4.2.3 Effect of Fiber Modification Using SAH and Initiator on Impact Properties of PBAT/EFB Biocomposites 87�4.2.4 Effects of Matrix Modification Using SAH and Initiator on Tensile Properties of PBAT/EFB Biocomposites 88�4.2.5 Effect of Matrix Modification Using SAH and Initiator on Flexural Properties of PBAT/EFB Biocomposites 95�4.2.6 Effect of Matrix Modification Using SAH and Initiator on Impact Properties of PBAT/EFB Biocomposites 99�

4.3 FTIR Analysis 102�4.4 Thermal Analysis of PBAT/EFB Fiber Biocomposites 113�

4.4.1 Thermal Gravimetric Analysis (TGA) 113�4.4.2 Dynamic Mechanical Analysis (DMA) 126�

4.5 Morphological Study of PBAT/EFB Biocomposites 140� 4.5.1 SEM of PBAT/EFB Biocomposite at 40% Fiber Loading 140� 4.5.2 SEM of PBAT/EFB Biocomposite After Fiber Modification 141� 4.5.3 SEM of PBAT/EFB Biocomposite After Matrix Modification 142�4.6 Water Absorption Study 144� 4.6.1 Effect of Fiber Loading on Water Absorption of PBAT/EFB Fiber Composite 145� 4.6.2 Effect of Chemical Threatment on Water Absorption of PBAT/EFB Fiber Composite 145 4.7 Biodegradation Study 148�

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4.7.1 Effect of Fiber Loading on Biodegradation of PBAT and PBAT/EFB Fiber Composites 150� 4.7.2 Effect of Chemical Treatments on Biodegradation of PBAT and BAT/EFB Fiber Composites 153�

5 CONCLUSIONS AND RECOMMENDATIONS 155�5.1 Conclusions 155�5.2 Recommendations 161�

REFERENCES 163 BIODATA OF STUDENT 181