UNIVERSITI PUTRA MALAYSIA

PREPARATION AND PHYSICO-CHEMICAL PROPERTIES OF POLYPROPYLENE AND OIL PALM EMPTY FRUIT BUNCH FIBRE

COMPOSITES

NORAZLINA BINTI HASHIM

FS 2008 26

PREPARATION AND PHYSICO-CHEMICAL PROPERTIES OF POLYPROPYLENE AND OIL PALM EMPTY FRUIT BUNCH FIBRE

COMPOSITES

NORAZLINA BINTI HASHIM

MASTER OF SCIENCE UNIVERSITI PUTRA MALAYSIA

2008

PREPARATION AND PHYSICO-CHEMICAL PROPERTIES OF POLYPROPYLENE AND OIL PALM EMPTY FRUIT BUNCH FIBRE

COMPOSITES

By

NORAZLINA BINTI HASHIM

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

January 2008

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

PREPARATION AND PHYSICO-CHEMICAL PROPERTIES OF

POLYPROPYLENE AND OIL PALM EMPTY FRUIT BUNCH FIBRE COMPOSITES

By

NORAZLINA BINTI HASHIM

JANUARY 2008

Chairman : Associate Professor Dr. Mohamad Zaki bin Ab Rahman, PhD Faculty : Science

Composites of polypropylene (PP) and oil palm empty fruit bunch (OPEFB) were

prepared by melt blending, and the effects of ethylene-butene copolymer (EBNR) as

an impact modifier, on the mechanical and thermal properties of OPEFB:PP

composites were investigated by using FTIR, DSC, TGA and SEM. Composites

were prepared at 10, 20, 30, 40, 50 and 60% by weight of fibre. Different fibre

loading, temperatures, rotation time and rotation speeds were tested to determine the

optimum condition of blending. Two range sizes of fibre were used in this study and

there are below 200 µm and between 200-315 µm of length (known as 200 µm and

315 µm). The study was mainly conducted on composite with 20% and 40% fibre

loading. The optimum temperature and reaction period for blending OPEFB with PP

were 170oC and 10 minutes with rotation speed at 50 rpm, respectively.

ii

The result from FTIR analysis indicated that the interaction is only physical between

the components of the composite. Tensile tests on the composites showed that EBNR

had a positive effect on the elongation at break and negative effect on tensile

modulus, but no improvement on tensile strength. This impact modifier was found to

decrease the stiffness of the composites. The impact strength was improved in

addition of EBNR, but for flexural test, no significant effect was observed. The

increasing in impact strength was shown for both notched and unnotched samples

starting from 1% of EBNR loading but they reduced when it reached at optimum

volume. Smaller fibre size, 200 µm gave higher impact strength compared to 315

µm.

The presence of EBNR on the composite made a weak improvement in thermal

stability as shown by thermogravimetric analysis (TGA). DMA studies established

that the EBNR led to reduction of stiffness and enhancing mobility of the resulting

composite. The surface morphology showed less void in EBNR composites where

OPEFB fibre seems to be covered with a smooth layer of EBNR.

The environmental degradation behaviour on the physical and mechanical properties

of OPEFB:PP composites has been studied with special reference to the influence of

ageing conditions like treatment with water, soil degradation, and chemical

resistance. With the increased of fibre loading, the water absorption was also

increased, and the addition of EBNR led to less water absorption, and the lowest

absorption was observed for 8% EBNR loading. Tensile properties decrease with

water uptake and time of immersion. The effect of alkaline (0.5M NaOH) and acidic

(0.5M HCl) solutions on the composites were investigated in a period of one month.

iii

The results showed the decreasing in tensile strength and mass. Temperature

dependence studies were also conducted at different temperature, 25oC, 45oC and

75oC, and found that the degradation was faster at higher temperature. The

biodegradability of composites was evaluated by the soil-burial test in six months.

The mass of composites slowly showed the decreasing after that time as expected.

iv

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai

memenuhi keperluan untuk ijazah Master Sains

PENYEDIAAN DAN CIRI-CIRI FIZIK-KIMIA KOMPOSIT

POLIPROPILENA DAN FIBER TANDAN KOSONG BUAH KELAPA SAWIT

Oleh

NORAZLINA BINTI HASHIM

JANUARI 2008 Pengerusi : Profesor Madya Dr. Mohamad Zaki bin Ab Rahman, PhD Fakulti : Sains

Komposit polipropilena (PP) dan tandan kosong buah kelapa sawit (OPEFB) telah

disediakan melalui kaedah adunan dan kesan menggunakan pengubah impak,

kopolimer etilena-butilena (EBNR) kepada sifat mekanik dan terma komposit

OPEFB:PP telah dikaji dengan menggunakan pelbagai teknik seperti FTIR, DSC,

TGA dan SEM. Komposit disediakan pada 10, 20, 30, 40, 50 dan 60% berdasarkan

berat fiber. Amaun fiber, suhu, jangka masa dan laju putaran yang berbeza telah

dikaji untuk mendapatkan keadaan adunan yang optimum. Dua skala saiz fiber

digunakan iaitu lebih kecil daripada 200 μm dan antara 200-315 μm panjang

(dikenali sebagai 200 μm dan 315 μm). Akhirnya, penambahan OPEFB sebanyak

20% dan 40% digunakan dalam kajian ini. Suhu optimum dan jangka masa untuk

adunan OPEFB dan PP adalah 170oC, 10 minit adunan dengan 50 rpm kelajuan

putaran.

v

Analisis FTIR menunjukkan hanya terdapat interaksi fizikal antara komponen dalam

komposit. Ujian tensil bagi komposit menunjukkan EBNR memberi kesan positif ke

atas pemanjangan pada takat putus dan merendahkan modulus tensil tetapi tiada

perubahan dalam kekuatan tensil dapat dilihat. Pengubah impak ini telah

merendahkan kesan kekakuan komposit. Kekuatan impak ditingkatkan dengan

penambahan EBNR di dalam komposit, tetapi tiada perubahan lenturan dikesan.

Peningkatan dalam kekuatan impak dapat dilihat untuk kedua-dua sampel yg ditakuk

dan tak ditakuk bermula daripada 1% EBNR tetapi berkurang setelah penambahan

EBNR mencapai tahap optimum. Saiz fiber yang lebih kecil, 200 μm memberi

kekuatan impak yang lebih tinggi berbanding saiz 315 μm.

Kehadiran EBNR dalam komposit tidak memperbaiki kestabilan terma seperti yang

ditunjukkan dalam analisis termogravimetri (TGA). Kajian DMA menunjukkan

EBNR menjurus kepada penurunan kekerasan dan menambahkan mobiliti komposit.

Kajian permukaan sampel menunjukkan kurang ruang kosong terbentuk di dalam

komposit EBNR di mana OPEFB diselaputi lapisan licin EBNR.

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

OPEFB:PP dikaji dengan melibatkan ujian sampel ke atas penyerapan air, degradasi

tanah dan ketahanan ke atas bahan kimia. Penyerapan air meningkat dengan

pertambahan fiber dan penambahan EBNR membawa kepada pengurangan kadar

penyerapan air dengan serapan terendah pada 8% kandungan EBNR. Ciri-ciri

kekuatan tensil berkurang dengan peningkatan penyerapan air dan waktu rendaman

vi

sampel. Kesan larutan alkali (0.5M NaOH) dan asid (0.5M HCl) ke atas komposit

dikaji selama satu bulan.

Keputusan menunjukkan pengurangan jisim dan kekuatan tensil. Kesan suhu ke atas

sampel dilakukan pada tiga keadaan suhu yang berbeza iaitu pada 25oC, 45oC and

75oC dan ia menunjukkan kadar degradasi bertambah dengan peningkatan suhu.

Proses biodegradasi komposit telah ditentukan dengan menanam sampel di dalam

tanah selama enam bulan. Jisim komposit telah berkurang secara perlahan-lahan

seperti yang dianggarkan.

vii

ACKNOWLEDGEMENTS

First of all, I would like to express my sincere and deepest appreciation to my

supervisor, Assoc. Professor Dr. Mohamad Zaki Ab Rahman, also co-supervisors Dr.

Nor Azowa Ibrahim and Professor Wan Md Zin Wan Yunus for their supervision,

invaluable guidance, unfailing help and superb tolerance throughout the course of

this work.

Special thanks to all the laboratory assistants in Department of Chemistry for their

help and advice.

I am also very grateful to Mr. Shahril, Mr Lim Chee Siong, Mrs. Zaidina, Mrs. Wan

Yusmawati, other lab mates and my housemates, 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

and Mr. Mohd Zailani Ismail whose have always believes 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.

viii

ix

This thesis was submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirement for the degree of Master of Science. The members of Supervisory Committee were as follows: Mohamad Zaki Ab Rahman, PhD Associate Professor Faculty of Science Universiti Putra Malaysia (Chairman) Wan Md Zin Wan Yunus, PhD Professor Faculty of Science Universiti Putra Malaysia (Member) Nor Azowa Ibrahim, PhD Lecturer Faculty of Science Universiti Putra Malaysia (Member)

AINI IDERIS, PhD Professor and Dean

School of Graduate Studies Universiti Putra Malaysia

Date: 10 April 2008

x

DECLARATION I hereby 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.

___________________________

NORAZLINA BINTI HASHIM Date: 29 February 2008

xi

TABLE OF CONTENTS

Page

ABSTRACT іі ABSTRAK v ACKNOWLEDGEMENTS vіii APPROVAL ix DECLARATION xi LIST OF TABLES xv LIST OF FIGURES xvi LIST OF ABBREVIATION/ NOTATION/GLOSSARY OF TERMS xix CHAPTER 1 INTRODUCTION 1.1 Background of Study 1 1.1.1 Toughening of PP matrix 3 1.1.2 Toughening of Filled Polymers 3 1.1.3 Size and Dispersion of Filler 4 1.2 General Background 5 1.2.1 The Fibres-Oil Palm Production 5 1.2.2 Oil Palm Waste Products 7 1.2.3 Utilisation 7 1.2.4 Properties of Oil Palm Empty Fruit Bunch Fibres 9 1.2.5 The Matrix – Thermoplastic 11 1.2.6 Properties of Thermoplastic 13 1.2.7 Thermoplastic Impact Copolymer 14 1.2.8 Mechanical Properties of Fibre – Thermoplastic Composites 14 1.3 Objectives 16 2 LITERATURE REVIEW 2.1 Overview of Natural Fibre Composites 17 2.2 Application of Composites 18 2.3 Improvement of Fibre – Thermoplastic Reaction 20 2.3.1 Coupling/Compatibilizing Agents 22 2.3.2 Elastomer as Impact Modifier 24 2.4 Factors Affecting the Mechanical Properties of 26 Fibre – Thermoplastic Composites 2.4.1 Effect of Fibre Loading 26 2.4.2 Effect of Fibre Size 27 2.4.3 Effect of Coupling/Compatibilizing Agents 28 2.5 Ageing Condition 30 2.5.1 Water Sorption 31 2.5.2 Chemical Resistance 33 2.5.3 Biodegradation 34 2.6 Thermal and Dynamic Mechanical Properties 35

xii

3 MATERIALS AND METHODS 3.1 Introduction 37 3.2 Materials 38 3.2.1 Oil Palm Empty Fruit Bunch (OPEFB) 38 3.2.2 Thermoplastic 38 3.2.3 Ethylene-Butene Copolymer 39 3.2.4 Chemicals 40 3.3 Methods 41 3.3.1 Preliminary Test 41 3.3.1.1 Effect of Fibre Loading and Fibre Size 41 3.3.1.2 Effect of Time, Temperature and Rotation 42 Speed of Blending 3.3.2 Effect of Ethylene-Butene Copolymer (EBNR) 43 3.4 Properties Assesment 43 3.4.1 Preparation of Test Specimens 43 3.4.2 Sample for Testing 44 3.4.3 Mechanical Properties 44 3.4.3.1 Tensile Properties 44 3.4.3.2 Flexural Properties 45 3.4.3.3 Izod Impact Resistance 46 3.4.4 Ageing Test 47 3.4.4.1 Water Sorption Test 47 3.4.4.2 Chemical Resistance Test 48 3.4.4.3 Biodegradability Test 48 3.5 Characterization of the Composites 49 3.5.1 Fourier Transform Infrared (FTIR) 49 3.5.2 Thermogravimetric Analysis (TGA) 49 3.5.3 Differential Scanning Calorimetry (DSC) 50 3.5.4 Dynamic Mechanical Analysis (DMA) 51 3.5.5 Scanning Electron Microscopy (SEM) 51

4 RESULT AND DISCUSSION 4.1 Preparation of OPEFB:PP Composites 52 4.2 Fourier Transform Infra Red (FTIR) 52 4.3 Tensile Properties of Composites 55 4.3.1 Effect of Fibre Loading on Tensile Strength 55 4.3.2 Effect of Fibre Loading on Tensile Modulus 57 4.3.3 Effect of Fibre Loading on Elongation at Break 58 4.3.4 Effect of Rotation Time on Tensile Strength 60 4.3.5 Effect of Rotor Speed on Tensile Strength 61 4.3.6 Effect of Temperature on Tensile Strength 62 4.3.7 Effect of EBNR on Tensile Properties 63 4.4 Flexural Properties of Composites 65 4.4.1 Effect of Fibre Loading on Flexural Properties 65 4.4.2 Effect of EBNR on Flexural Properties 68 4.5 Impact Properties of Composites 69 4.5.1 Effect of Fibre Loading on Impact Strength 69 4.5.2 Effect of EBNR on Impact Strength 73 4.6 Thermogravimetry Analysis 75

xiii

4.7 Differential Scanning Calorimetry Analysis 80 4.8 Dynamic Mechanical Properties of Composites 82 4.8.1 Storage Modulus of Composites 82

4.8.2 Loss Modulus of Composites 85 4.8.3 Tan Delta of Composites 87 4.9 Scanning Electron Microscopy 89 4.10 Ageing Tests 92 4.10.1 Water Sorption 92 4.10.1.1 Water Uptake of Composites 92 4.10.1.2 Effect of Water Uptake on Properties of 95

Composites 4.10.1.3 Effect of Water Uptake on Surface Morphology 100 of Composites 4.10.2 Chemical Resistance 102

4.10.2.1 Weight Loss of Samples 102 4.10.2.2 Effect of Chemicals (HCl and NaOH) on Tensile 103 Strength of Composites 4.10.3 Biodegradation Test 105 4.10.3.1 Weight Loss of Samples 105

5 CONCLUSIONS AND RECCOMENDATIONS

5.1 Conclusions 109 5.2 Recommendations 112

REFERENCES 114 BIODATA OF THE AUTHOR 123

xiv

LIST OF TABLES

Table Page 1.1 Growth of the oil palm trade ('000t) 6 1.2 Chemical composition of oil palm fibres and some important natural 9

fibres

1.3 The fibre morphology of oil palm trunk compared to other fibres 10

1.4 Projected demand and supply situation in Malaysia 12

1.5 Application of plastic by percentage in Malaysia 12

2.1 Value for the surface tension of plastics and cellulose based materials 21

2.2 Tensile properties of PP/Hemp and PP/Hemp/PP-g-GMA properties 29

2.3 The effect of boiling water on Young's modulus and elongation at 32 break of the composite with different fibre loadings and chemical

treatments after exposure in boiling water for 7 hours

3.1 Typical properties of polypropylene (PP) 39

3.2 The properties of EBNR 7467,00 ethylene-butene copolymer 40

3.3 Composition of samples prepared 42

4.1 Weigth loss of samples at different temperature after 28 days 103 immersion in different media solutions

xv

LIST OF FIGURES Figure Page

1.1 The empty fruit bunch (EFB) photograph 8

1.2 General formula of plastic 11

2.1 Role of compatibilizing agent at the interface between natural filler 23 and matrix polymer

4.1 FTIR spectra for PP, OPEFB and OPEFB:PP composites 53

4.2 FTIR spectra for OPEFB:PP composites with EBNR 54

4.3 Effect of fibre loading on tensile strength of OPEFB:PP composites 56 for different size of fibre

4.4 Effect of fibre loading on tensile modulus and percentage of elongation 59 at break of OPEFB:PP composites for different size of fibre

4.5 Effect of rotation time on tensile strength 60

4.6 Effect of rotor speed on tensile strength 61

4.7 Effect of blending temperature on tensile strength 62

4.8 Effect of EBNR loading on tensile strength for different particle size 63 and percentage of fibre

4.9 Effect of EBNR loading on tensile modulus for different particle size 64 and percentage of fibre

4.10 Effect of EBNR on percentage of elongation at break for different 64 particle size and percentage of fibre

4.11 Effect of fibre loading and particle size on flexural strength OPEFB:PP 66 composites 4.12 Effect of fibre loading and particle size on flexural modulus OPEFB:PP 67 composites 4.13 Effect of EBNR loading on flexural strength for different particle size 68

and percentage of fibre

4.14 Effect of EBNR loading on flexural modulus for different particle size 69 and percentage of fibre

xvi

4.15 Izod impact test as a function of the fibre loading for notched OPEFB:PP 70 Composites

4.16 Izod impact test as a function of the fibre loading for unnotched 71 OPEFB:PP composites

4.17 Effect of EBNR loading on impact strength of notched samples 74

4.18 Effect of EBNR loading on impact strength of unnotched samples 74

4.19 TG and DTG thermograms of OPEFB 76

4.20 TG and DTG thermograms of OPEFB:PP composite of 40% of OPEFB 77

4.21 TG and DTG thermograms of OPEFB:PP with EBNR composite 78

4.22 Thermogravimetry of composites 79

4.23 DSC curves of OPEFB 80

4.24 DCS curves of OPEFB:PP composite 81

4.25 Influence of fibre content and size on storage modulus of PP 83

4.26 Influence of fibre content and EBNR loading on storage modulus 84 of composites

4.27 Influence of fibre content and size on loss modulus of PP 85

4.28 Influence of fibre content and EBNR loading on loss modulus of 86 composites

4.29 Influence of fibre content and size on tan delta of PP 87

4.30 Influence of fibre content and EBNR loading on tan delta of 88 composites

4.31 SEM micrographs of fracture surfaces of OPEFB:PP composite at 90 (a) 50x and (b) 300x magnifications

4.32 SEM micrographs of fracture surfaces of OPEFB:PP with EBNR 91 composite at (a) 50x and (b) 300x magnifications

4.33 Effect of OPEFB loading and particle size of fibre on water uptake 93

4.34 Effect of EBNR loading on water uptake in composites with 20% 94 of fibre loading

4.35 Effect of EBNR loading on water uptake in composites with 40% 95 of fibre loading

xvii

4.36 Effect of water uptake on tensile strength of composites 97

4.37 Effect of water uptake on tensile modulus of composites 98

4.38 Effect of water uptake on elongation at break of composites 98

4.39 Effect of water uptake on tensile strength of composites with EBNR 99

4.40 SEM micrograph of OPEFB:PP composite (a) before ageing; 100 (b) after ageing at 300x magnification

4.41 SEM micrograph of OPEFB:PP composite with EBNR (a) before 101 ageing; (b) after ageing at 300x magnification

4.42 Tensile strength of composites after immersion in HCl and NaOH 104

4.43 Weight loss of neat PP and OPEFB:PP composites during the burial 106 test in soil

4.44 Weigth loss of OPEFB:PP composites for 20% of OPEFB with 107 different EBNR loading during the burial in soil

4.45 Weigth loss of OPEFB:PP composites for 40% of OPEFB with 108 different EBNR loading during the burial in soil

xviii

LIST OF ABBREVIATIONS/NOTATION/GLOSSARY OF TERMS

ABS Acrylonitrile-butadiene-styrene

AS (3-aminopropyl)-triethoxysilane

ASTM American Standard for Testing and Materials

BGRP Bamboo fibre reinforced polypropylene composite

CPE Chlorinated polyethylene

DMA Dynamic mechanical analysis

DSC Differential scanning calorimetry

DTG Differential thermogravimetry

EBNR Ethylene-butene copolymer

EFB Empty fruit bunch

EPDM Ethylene/propylene/diene copolymer

EPDM-MAH Maleated ethylene/propylene/diene copolymer

EPM Ethylene/propylene copolymer

EP-MAH Maleated ethylene-propylene

EVA Ethylene/vinyl acetate

FFB Fresh fruit bunch

FTIR Fourier transform infrared

GF Glass fibre

GMA Glycidyl metacrylate

GP/PP Glass fibre-polypropylene composite

HCl Hydrochloric acid

HDPE High density polyethylene

LDPE Low density polyethylene

xix

LF/PP Luffa fibre-polypropylene composite

MAPP Maleic anhydride-polypropylene

MMA Methyl metacrylate

MPOB Malaysian Palm Oil Bard

MS 3-(trimethoxysilyl)-1-propanethiol

NaOH Sodium hydroxide

NBR Acrylonitrile/butadiene elastomer

OPEFB Oil palm empty fruit bunch

OPEFB:PP Oil palm empty fruit bunch-polypropylene composite

PE Polyethylene

PE/WF Polyethylene-wood fibre composite

PET Polyester

PIB Polyisobutylene

PLA Poly-lactic acid

PMMA Polymethyl metacrylate

PORIM Palm Oil Research and Development Board

PP Polypropylene

PP/RNFC Polypropylene-recycled newspaper cellulose fibre

PP/WF Polypropylene-wood fibre composite

PPG Polypropylene glycol

PP-g-GMA Polypropylene grafted glycidyl metacrylate

PS Polystyrene

PVC Polyvinyl chloride

R&D Research and development

RNFC Recycled newspaper cellulose fibre

xx

xxi

SBS Styrene-butadiene-styrene

SEBS-MAH Maleated styrene-ethylene/butadiene-styrene

TDI Toluene diisocyanate

TDI/PPG Toluene-2,4-diisocyanate/polypropylene glycol

Tg Glass transition

TG Thermal gravimetric

TGA Thermogravimetric analysis

Tm Melting temperature

TPO Ethylene/propane thermoplastic elastomer

UV Ultra-violet

WPC Wood-plastic composite

CHAPTER 1

INTRODUCTION

1.1 Background of Study

Advanced in science and technology pose new challenges in relation to certain

environmental issues, such as biodegradability, recyclability, eco-friendliness etc., that

needs to be addressed to help preserve and protect our environment. Composite

materials from the annually renewable natural fibres and biodegradable matrices have

been developed in the past decades in an attempt to find alternatives to the fossil fuel-

based polymeric materials in the automotive and packaging industries.

The benefits offered by lignocellulosic materials include making the final product lighter

and decreasing the wear of the machinery used in the production process. Moreover,

lignocellulosic materials have the advantages of low cost, biodegradability and the

absence of residues or toxic byproducts, whereas inorganic materials such as glass fibre,

carbon fibre, talc, clay, synthetic fibre, etc. do not have these benefits (Yang et al., 2004;

Lee et al., 2004). Yet another attraction of using these materials is the fact that it would

allow various agro-wastes to be appropriately recycled.

The performance and properties of composite materials depend on the properties of the

individual components and their interfacial compatibility. To ensure appropriate

interfacial interactions their surface properties must be modified accordingly.

1