UNIVERSITI PUTRA MALAYSIA

BIOCOMPOSITES FROM BIODEGRADABLES POLYMER AND MODIFIED OIL PALM EMPTY FRUIT BUNCH FIBER

SITI NUR AFIFI BINTI AHMAD

FS 2009 15

BIOCOMPOSITES FROM BIODEGRADABLES POLYMER AND MODIFIED OIL PALM EMPTY FRUIT BUNCH FIBER

By

SITI NUR AFIFI BINTI AHMAD

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

March 2009

BIOCOMPOSITES FROM BIODEGRADABLE POLYMER AND MODIFIED OIL PALM EMPTY

FRUIT BUNCH FIBER

SITI NUR AFIFI BINTI AHMAD

MASTER OF SCIENCE UNIVERSITI PUTRA MALSYIA

2009

BIOCOMPOSITES FROM BIODEGRADABLE POLYMER OF POLYCAPROLACTONE AND OIL PALM EMPTY FRUIT BUNCH FIBER

By

SITI NUR AFIFI BINTI AHMAD

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

May 2009

Abstract of the thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirement for the degree of Master of Science

BIOCOMPOSITES FROM BIODEGRADABLES POLYMER AND MODIFIED

OIL PALM EMPTY FRUIT BUNCH FIBER

By

SITI NUR AFIFI BINTI AHMAD

March 2009

Chairman : Nor Azowa Binti Ibrahim, PhD

Faculty : Science

Natural fiber reinforced composites using thermoplastic such as polypropylene and

polyethylene as a matrix produced partially biodegradable composites. In order to

produce totally biodegradable composites or green composites, poly(ε-caprolactone)

was used as the matrix. However the hydrophilic nature of oil palm empty fruit bunch

fiber (natural fiber) affects negatively its adhesion to hydrophobic polymer matrix, thus

to improve the compatibility of both components a cross-linker, poly(N-

vinylpyrrolidone) and electron beam radiation have been proposed. The composites of

OPEFB:PCL were prepared by melt blending technique using Haake Internal Mixer.

The effect on the amount PVP and doses of electron beam irradiation on mechanical

properties of OPEFB:PCL were studied.

The properties of OPEFB:PCL composites were improved by addition of 1% by weight

of PVP and irradiated with 10 kGy of electron beam. The FTIR spectra indicate a slight

interaction between OPEFB with PCL after adding PVP and irradiation in agreement

ii

with the significant improvement of mechanical properties. The tensile strength of

OPEFB:PCL without PVP and treatment is 10.3 MPa whereas after addition of PVP and

treatment the tensile strength increased to 16.7 MPa indicating good stress transfer from

OPEFB to PCL matrix. Addition of PVP and treatment with electron beam also increase

the flexural strength and modulus to 24.32 and 8.69 % respectively. The impact strength

is also slightly increased with PVP and irradiation which is about 2.28 %.

From XRD patterns, it can be inferred that the amorphous phase of the composites is

slightly increased after adding PVP whereas no significant change was observed after

irradiation. Thermal properties of the composites were studied by thermogravimetric

analysis (TGA) and differential scanning calorimetry (DSC). From the results, there is

also no significant improvement observed for thermal stability of the composites. The

surface morphology of the facture surface obtained from tensile test shows no fiber pull

out indicating interaction between the OPEFB and PCL after addition of PVP and

irradiation.

The environmental degradation behavior on the physical properties of OPEFB:PCL

composites has been studied with special reference to the influence of ageing conditions

like treatment with water and soil degradation. From water uptake analysis, it can be

inferred that the composites become more water resistant after the irradiation. The soil

burial test was carried out in 3 months, indicates that irradiation and fiber loading tend

to promote degradation of the composites.

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

BIOKOMPOSIT DARIPADA POLIMER YANG TERBIODEGRADASI DAN

TANDAN KOSONG BUAH KELAPA SAWIT (OPEFB) YANG TELAH DIUBAHSUAI

Oleh

SITI NUR AFIFI BINTI AHMAD

Mac 2009

Pengerusi : Nor Azowa Binti Ibrahim, PhD

Fakulti : Sains

Komposit yang diperkuatkan dengan fiber semulajadi menggunakan termoplastik seperti

polipropilena (PP) dan polietelina (PE) sebagai matriks menghasilkan komposit yang

separa terbiodegradasi. Bagi menghasilkan komposit yang terbiodegradasi sepenuhnya,

polikaprolakton (PCL) telah digunakan sebagai matriks. Walau bagaimanapun sifat

hidrofilik fiber tandan kosong buah kelapa sawit (fiber semulajadi) memberi kesan

negatif terhadap perlekatan dengan matriks polimer yang hidrofobia, oleh yang

demikian, untuk meningkatkan kesesuaian kedua-dua komponen penaut silang, poli(N-

vinilpirolidon) (PVP) dan radiasi alur elektron digunakan. Komposit OPEFB:PCL

disediakan dengan teknik pengadunan lebur menggunakan alat pencampur dalaman

‘Thermo Haake’. Kesan kuantiti PVP dan dos alur elektron yang digunakan terhadap

ciri-ciri mekanikal OPEFB:PCL telah dikaji.

iv

Ciri-ciri komposit ditingkatkan dengan penambahan PVP sebanyak 1% dan radiasi alur

elektron dengan dos sebanyak 10 kGy. Spektra FTIR menunjukkan sedikit interaksi di

antara fiber dan PCL selepas penambahan PVP dan radiasi sejajar dengan peningkatan

yang ketara pada ciri-ciri mekanikalnya. Kekuatan tensil OPEFB:PCL tanpa PVP dan

rawatan adalah 10.3 MPa manakala selepas penambahan PVP dan rawatan kekuatan

tensil meningkat kepada 16.7 MPa yang menunjukkan pemindahan ketegangan yang

baik daripada OPEFB kepada matriks PCL. Penambahan PVP dan rawatan dengan alur

elektron juga menaikkan kekuatan dan modulus flektural masing-masing daripada 16.8

kepada 22.2 MPa dan 1072 kepada 1174 MPa. Kekuatan kesan hentaman juga

meningkat sedikit dengan penambahan PVP dan radiasi iaitu sebanyak 2.28%.

Daripada analisis XRD, ia boleh disimpulkan bahawa fasa tak berbentuk komposit

tersebut sedikit bertambah selepas penambahan PVP manakala tiada perubaham yang

ketara didapati selepas radiasi. Sifat-sifat terma bagi komposit OPEFB:PCL telah dikaji

dengan menggunakan Analisis Thermogravimetri (TGA) dan Analisis kalorimetri

pengimbas pembezaan (DSC). Tiada peningkatan kestabilan terma yang jelas pada

komposit tersebut yang didapati daripada pemerhatian. Tata bentuk permukaan pada

pecahan permukaan ujian tensil menandakan tiada fiber yang tercabut menunjukkan

interaksi di antara OPEFB dan PCL selepas penambahan PVP dan radiasi.

Kesan degradasi persekitaran kepada ciri-ciri fizikal dan mekanikal bagi komposit

OPEFB:PCL telah dikaji dengan melibatkan ujian sampel ke atas penyerapan air dan

degradasi tanah. Merujuk kepada analisis kadar penyerapan air, ia boleh disimpulkan

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bahawa komposit menjadi lebih tahan kepada serapan air selepas rawatan radiasi.

Penanaman sampel dalam tanah dilakukan selama 3 bulan, ia menunjukkan bahawa

radiasi dan pemuatan fiber lebih cenderung menggalakkan kepada degradasi komposit.

vi

ACKNOWLEDGEMENTS

First of all, I want to express my deepest appreciation to my project supervisor Dr. Nor

Azowa Ibrahim, co-supervisors Professor Dato’ Dr. Wan Md Zin Wan Yunus and Dr.

Khairul Zaman Mohd Dahlan for their supervision, brilliant ideas, technical guidance

and superb tolerance throughout the course of this work.

Special thanks to all the staffs at BTPS, Malaysian Nuclear Agency for their unfailing

help and advice. I would also like to say thank you to all the laboratory assistants and

staffs in Faculty of Science for their sincere contribution that has made this research

work possible.

I want to dedicate my gratitude to all my colleagues in polymer group whose help,

suggestions, encouragement and companion are of great help in sustaining the morale

and enthusiasm.

Last but not least, I would like to express my deepest gratitude to my beloved family,

Mohammad Fairuz and friends who have always believe in me, and endured with me

during difficult times. Without their unconditional and endless love, it would not have

been possible for me to complete this Master of Science thesis.

vii

Financial support from Universiti Putra Malaysia and Ministry of Science, Technology

and Innovation of Malaysia for the National Science Fellowship Award is gratefully

acknowledged.

viii

I certify that an Examination Committee has met on 24th March 2009 to conduct the final examination of Siti Nur Afifi Ahmad on her Master of Science thesis entitled “Biocomposites from Biodegradables Polymer and Modified Oil Palm Empty Fruit Bunch Fiber” 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. Members of the Examination are as follows: Chairman, PhD Anuar Kassim Faculty of Science Universiti Putra Malaysia (Chairman) Examiner 1, PhD Zaki Abd. Rahman Faculty of Science Universiti Putra Malaysia (Internal Examiner) Examiner 2, PhD Mansor Ahmad Faculty of Science Universiti Putra Malaysia (Internal Examiner) Examiner, PhD Rusli Daik School of Chemical Sciences and Food Technology Universiti Kebangsaan Malaysia (External Examiner)

______________________________ BUJANG KIM HUAT, PhD Professor and Deputy Dean School of Graduate Studies Universiti Putra Malaysia

Date:

ix

This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the requirement for the degree of Master of Science. The members of Supervisory Committee are as follows: Nor Azowa Ibrahim, PhD Faculty of Science Universiti Putra Malaysia (Chairman) Wan Md Zin Wan Yunus, PhD Professor Faculty of Science Universiti Putra Malaysia (Member) Khairul Zaman Mohd Dahlan, PhD Director Block of Processing Technology and Radiation Malaysian Nuclear Agency

________________________________ HASANAH MOHD GHAZALI, PhD Professor and Dean School of Graduate Studies Universiti Putra Malaysia

Date: 9 July 2009

x

DECLARATION I declare that the thesis is based on my original work except 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.

___________________________

SITI NUR AFIFI AHMAD Date:

xi

TABLE OF CONTENTS ABSTRACT ii ABSTRAK iv ACKNOWLEDGEMENT vii APPROVAL ix DECLARATION x LIST OF TABLES xvi LIST OF FIGURES xvii LIST OF ABBREVIATIONS xix CHAPTER

1 INTRODUCTION 1.1 General Background 1

1.1.1 Producing of fully biodegradable composites 3

1.2 Background of Study 4 1.2.1 The Matrix – Thermoplastic 4 1.2.2 Properties of Poly( -caprolactone) 5 1.2.3 Oil Palm By-products 6 1.2.4 Utilization 7 1.2.1 Properties of Oil Palm Empty Fruit Bunch Fibers 8 1.2.2 Fiber-thermoplastic Composites 9 1.2.3 Compatibilizing Agent (Poly(N-vinylpyrrolidone)) 10 1.2.4 Electron Beam Irradiation 11

1.3 Research Problems 11 1.4 Scope of the Study 14 1.5 Objectives of the Study 15

2 LITERATURE REVIEW

2.1 Overview of Biocomposites from Biodegradable Materials 16 2.1.1 Poly( -caprolactone) 17 2.1.2 Natural Fibers as the Reinforcing Filler 19

2.2 Application of Composites 21

2.3 Problems with Fiber-Thermoplastic Composites 23 2.4 Methods for Surface Modification of Natural Fibers 24

xii

2.4.1 Physical Methods 26 2.4.2 Chemical Methods 27 2.4.3 Radiation Methods 30

2.5 Factors Affecting the Properties of Natural Fiber Composites 33

2.5.1 Effect of Fiber Loading 33 2.5.2 Effect of fiber size 35

2.6 Thermal and Dynamic Mechanical Properties 36

2.7 Water Resistance and Biodegradability of OPEFB:PCL 39

Composites 2.7.1 Water Sorption 39 2.7.2 Biodegradation 40

3 MATERIALS AND METHODS 3.1 Introduction 42 3.2 Materials 42

3.2.1 Oil Palm Empty Fruit Bunch Fiber (OPEFB) 42 3.2.2 Thermoplastic 43

3.2.3 poly(N-vinylpyrrolidone) 44 3.2.4 Chemicals 44

3.3 Preparation of the Composites 45

3.3.1 Effect of Fiber Loading 45 3.3.2 Effect of Electron beam Irradiation 46 3.3.3 Effect of poly(N-vinylpyrrolidone) 46 3.4 Mechanical and Physical Testings 46

3.4.1 Preparation of Test Specimens 47 3.4.2 Tensile Properties 47 3.4.3 Flexural Properties 48 3.4.4 Izod Impact Resistance 49 3.4.5 Water Sorption Test 50 3.4.6 Biodegradability Test 51 3.5 Characterization of the Composites 51

3.5.1 Fourier Transform Infrared (FTIR) 52 3.5.2 X-Ray Diffraction Analysis 52

3.5.3 Thermogravimetric Analysis (TGA) 53 3.5.4 Differential Scanning Calorimetry (DSC) 53 3.5.5 Dynamic Mechanical Analysis (DMA) 54

3.5.6 Scanning Electron Microscopy (SEM) 55

xiii

4 RESULTS AND DISCUSSIONS 4.1 Preparation of OPEFB:PCL Composites 56

4.2 Fourier Transform Infra Red (FTIR) Analysis 56 4.3 X-Ray Diffraction Analysis 57

4.4 Tensile Properties of Composites 59

4.4.1 Effect of fiber loading on tensile strength 59 4.4.2 Effect of fiber loading on tensile modulus 60 4.4.3 Effect of fiber loading on elongation at break 62 4.4.4 Dose optimization of tensile properties 63 4.4.5 Comparative study of electron beam irradiation on 66 tensile properties 4.4.6 Effect of Irradiation and PVP on tensile strength 69 4.4.7 Effect of Irradiation and PVP on tensile modulus 70 4.4.8 Effect of Irradiation and PVP on elongation at break 71

4.5 Flexural Properties of Composites 72 4.5.1 Effect of Irradiation and PVP on flexural properties 73

4.6 Impact Properties of Composites 75 4.6.1 Effect of Irradiation and PVP on impact strength 75

4.7 Thermogravimetry Analysis (TGA) 77 4.8 Differential Scanning Calorimetry 81

4.9 Dynamic Mechanical Properties of Composites 85 4.9.1 Storage modulus of composites 85 4.9.2 Loss modulus of composites 86 4.9.3 Tan delta of composites 87

4.10 Scanning Electron Microscopy (SEM) 89

4.11 Water Sorption Test 90 4.11.1 Water uptake of samples 91

4.12 Biodegradability Test 93

4.12.1 Weight loss of samples 94

5 CONCLUSIONS

5.1 Conclusions 96 5.2 Recommendations 98

xiv

REFERENCES 100 BIODATA OF STUDENT 113 LIST OF PUBLICATION

xv

LIST OF TABLES

Tables Page

1.1 Mechanical performance of parent and modified oil palm fibers 8

1.2 Physical and chemical characteristics of glass and oil palm fiber 9

3.1 Properties of thermoplastic poly( -caprolactone) 43

3.2 Physical properties of poly(N-vinylpyrrolidone) 44

3.3 Composition of samples prepared 45

4.1 Results of analysis of thermograms form irradiated and non irradiated 80 samples 4.2 DSC melting point and melting enthalpy of the neat films of PCL and 84 biocomposites.

xvi

LIST OF FIGURES

Figures Page

2.1 Reaction pathways during polymer biodegradation 41

4.1 FTIR spectra of OPEFB:PCL composites 57

4.2 XRD patterns of PCL, OPEFB and OPEFB:PCL and comparison of 58 XRD patterns between irradiated and non-irradiated composites 4.3 Effect of fiber loading on tensile strength of OPEFB:PCL composites 60 4.4 Effect of fiber loading on tensile modulus of OPEFB:PCL composites 62 4.5 Effect of fiber loading on elongation at break of OPEFB:PCL 63 composites 4.6 Effect of electron beam irradiation on tensile strength of OPEFB:PCL 64

composites at various doses 4.7 Effect of electron beam irradiation on tensile modulus of OPEFB:PCL 65

composites at various doses

4.8 Effect of electron beam irradiation on elongation at break of 66 OPEFB:PCL composites at doses

4.9 Comparative study with electron beam irradiation method on tensile 67 strength of OPEFB:PCL composites 4.10 Comparative study with electron beam irradiation method on tensile 68

modulus of OPEFB:PCL composites 4.11 Comparative study wit6h electron beam irradiation method on 68

elongation at break of OPEFB:PCL composites 4.12 Tensile strength of irradiated and non-irradiated OPEFB:PCL 70

composites at various PVP content (crosshead speed: 5 mm/min, at room temp.)

4.13 Tensile modulus of irradiated and non-irradiated OPEFB:PCL 71

composites at various PVP content (crosshead speed: 5 mm/min,

xvii

at room temp.) 4.14 Elongation at break of irradiated and non-irradiated OPEFB:PCL 72

composites at various PVP content (crosshead speed: 5 mm/min, at room temp.)

4.15 Flexural strength of irradiated and non-irradiated OPEFB:PCL 74

composites at various PVP content 4.16 Flexural Modulus of irradiated and non-irradiated OPEFB:PCL 75

composites at various PVP content 4.17 Unnotched impact strength of irradiated and non-irradiated 76

OPEFB:PCL composites at various PVP content 4.18 Notched impact strength of irradiated and non-irradiated 77

OPEFB:PCL composites at various PVP content 4.19 TG and DTG thermograms of OPEFB 78 4.20 DTG thermograms of OPEFB 79 4.21 TG thermograms of OPEFB 80 4.22 DSC curve of OPEFB 81 4.23 DSC curve of OPEFB:PCL composites 82 4.24 DSC curve of OPEFB:PCL composites with PVP 83 4.25 DSC curve of OPEFB:PCL composites with PVP, irradiated at 10 kGy 83 4.26 Storage modulus of OPEFB: PCL composites 86 4.27 Loss modulus of OPEFB:PCL composites 87 4.28 Tan delta of OPEFB:PCL composites 89 4.29 SEM micrographs tensile fracture surface of OPEFB:PCL composites 90 4.30 Water uptake of irradiated and non irradiated samples 93 4.31 Weight loss of OPEFB:PCL composites 95

xviii

LIST OF ABBREVIATION/NOTATION

ABS Acrylonitrile-butadiene-styrene

AS (3-aminopropyl)-triethoxysilane

ASTM American Standard for Testing and Materials

BGRP Bamboo fiber reinforced polypropylene composite

CPE Chlorinated polyethylene

DMA Dynamic mechanical analysis

DSC Differential scanning calorimetry

DTG Differential thermogravimetry

EFB Empty fruit bunch

EP-MAH Maleated ethylene-propylene

EVA Ethylene/vinyl acetate

FFB Fresh fruit bunch

FTIR Fourier transform infrared

GF Glass fiber

GMA Glycidyl metacrylate

GP/PP Glass fiber-polypropylene composite

HDPE High density polyethylene

LDPE Low density polyethylene

MAPP Maleic anhydride maleated polypropylene

MMA Methyl methacrylate

MPa Mega Pascal

MPOB Malaysian Palm Oil Board

MS Malaysian Standard

OPEFB Oil palm empty fruit bunch

OPEFB:PP Oil palm empty fruit bunch-polypropylene composite

PE Polyethylene

PE/WF Polyethylene-wood fiber composite

PET Polyester

PIB Polyisobutylene

xix

xx

PLA Poly-lactic acid

PMMA Polymethyl metacrylate

PORIM Palm Oil Research Institute of Malaysia

PP Polypropylene

PP/RNFC Polypropylene-recycled newspaper cellulose fiber

PP/WF Polypropylene-wood fiber composite

PPG Polypropylene glycol

PP-g-GMA Polypropylene grafted glycidyl metacrylate

PS Polystyrene

PVC Poly(vinyl chloride)

PVP poly(N-vinylpyrrolidone)

R&D Research and development

RNCF Recycled newspaper cellulose fiber

SBS Styrene-butadiene-styrene

Tg Glass transition temperature

TGA Thermogravimetric analysis

Tm Crystalline melting point

UV Ultra-violet

WPC Wood-plastic composite

CHAPTER 1

INTRODUCTION

1.1 General Background

One major drawback to polymers is the problem of disposal. Since they are somewhat

resistive to degradation, polymers tend to accumulate in disposal system, the landfill.

Questions about how do polymers and products of biodegradation affect the

environment must be taken seriously.

Many solutions have been proposed for soil waste management of plastics, like

recycling, incineration, landfill disposal, and degradable plastics. Polymer recycling is

an environmentally attractive solution, but the results on a worldwide scale have not

been successful because recycling will not yield quality products due to the

heterogeneous nature of plastics. Incineration of plastics will release toxic gasses and

vapors, which results in a serious health hazard. The use of plastic in landfill operation

is least preferred because of space constraint. For these reasons, many investigations

have been carried out on the synthesis and manufacture of new polymeric materials

which are friendlier to the environment (Abdel-Rehim et al., 2004). Consequently, the

use of biodegradable polymers such as poly(ε-caprolactone) (PCL) seems to be the best

solution to this problem.

Major difficulties in using PCL are poor availability, poor process ability, low

toughness, high price and low moisture stability (Chen et al., 2005(a); Wang et al.,

1998). The 60°C melting point of PCL is also too low for many applications.

Preparation of blends or conventional composites using inorganic or natural fillers,

respectively are among the routes to improve some of the properties of biodegradable

polymers.

Lignocellulosic materials, which are among the most environmentally friendly agro

wastes were used as reinforcing filler as a substitute for synthetic materials to obtain

more biodegradable composites (Hottotuwa et al., 2002). Properties and cost of

biodegradable polymers can be also modified and improved through the use of

lignocellulosic fibers that reduce the cost of the material without modifying their

biodegradability (Iannace et al., 1999). Furthermore, these materials can be easily

obtained from waste products and have a minimal effect on the environment, due to

their biodegradable properties. Thus, the emphasis has increasingly been placed on these

composites, which may play a major role in resolving some of the pressing

environmental issues.

Natural fibers in the form of fiber or/and particulate have been widely used as

reinforcing fillers in thermoplastic composites materials. These natural fibers are lighter,

and cheaper, decrease the erosion of the manufacturing machinery and provide much

higher strength per unit mass than most inorganic fillers. Besides ecological

considerations, several technical aspects promote the renewed interest for the fibers as

2