Optimisation And Characterisation Of Functionalised Graphene Nanoplatelets Filled NR/EPDM Nanocomposites.

TITLE OF THE THESIS

(Uppercase, centred, bold, 18 point gold colored font)

X

OPTIMISATION AND CHARACTERISATION OF

FUNCTIONALISED GRAPHENE NANOPLATELETS

FILLED NR/EPDM NANOCOMPOSITES

MAZLIN AIDA BT MAHAMOOD

MASTER OF SCIENCE

IN MANUFACTURING ENGINEERING

Faculty of Manufacturing Engineering

OPTIMISATION AND CHARACTERISATION OF FUNCTIONALISED

GRAPHENE NANOPLATELETS FILLED NR/EPDM

NANOCOMPOSITES

Mazlin Aida Binti Mahamood

Master of Science in Manufacturing Engineering

OPTIMISATION AND CHARACTERISATION OF FUNCTIONALISED GRAPHENE NANOPLATELETS FILLED NR/EPDM NANOCOMPOSITES

MAZLIN AIDA BINTI MAHAMOOD

A thesis submitted

in fulfillment of the requirements for the degree of Master of Science in Manufacturing Engineering

Faculty of Manufacturing Engineering

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

DECLARATION

I declare that this thesis entitled “Optimisation and Characterisation of Functionalised Graphene Nanoplatelets Filled NR/EPDM Nanocomposites” is the result of my own research except as cited in the references. The thesis has not been accepted for any degree and is not concurrently submitted in candidature of any other degree.

Signature : ………... Name : ………... Date : ………...

APPROVAL

I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms of scope and quality for the award of Master of Science in Manufacturing Engineering.

Signature : ………... Supervisor’s Name : ………...

Date : ………...

DEDICATION

To God, who gave me the life, strength and the guidance, to my beloved family, husband, mama, abah, abang, kakak dan adik-adik, thank you for giving me full encouragement and love. To my respective supervisor and lecturer, thank you for the lesson and knowledge. To all

i ABSTRACT

Nowadays, polymer nanocomposites have attracted great interest due to their outstanding improvements in material properties as compared to neat polymers or conventional composites. This research is to prepare and characterise the Natural Rubber (NR) / Ethylene Propylene Diene Monomer (EPDM) filled Graphene Nanoplatelets (GNPs) nanocomposites for mechanical and thermal performance compared than unfilled NR/EPDM blend. The stage 1 of the research is to improve the miscibility between NR and EPDM rubber phases by using MAH grafted EPM compatibiliser. NR/EPDM blends were compounded using a Haake internal mixer and vulcanised by a semi-EV curing system in accordance to ASTM D3192. The response surface methodology (RSM) by Design Expert 6.0.10 software was used to optimize an internal mixer processing parameters and amount of MAH grafted EPM compatibiliser towards the maximum tensile strength (TS). The optimum mixing parameters was mixing temperature of 110°C, rotor speed of 40 rpm, mixing period of 5 mins and 5 phr amount of MAH grafted EPM compatibiliser with the highest repeatability and R2 _{value of ~99.00%. The stage 2 of the research was focusing on} the graphene nanoplatelets surface treatment by the non-covalent methods using polyethyleneimines (PEI) in an ethanol: distilled water medium (75:25). The physical adsorption of PEI on GNPs by non-covalent treatment was proposed as a possible interaction mechanism. During the stage 3 of this research, the effects of GNPs surface treatment and loading (0.25-5.00 wt. %) to the processability, mechanical, physical, thermal and morphological properties of the nanocomposites were studied. The surface treatment of GNPs enhanced the filler-matrices interaction in the NR/EPDM blend nanocomposites. The nanocomposites with 3.00 wt. % PEI-treated GNPs possessed outstanding mechanical properties compared to the unfilled blends and filled samples without treatment (tensile strength of 27.78 MPa, 19.65 MPa and 23.34 MPa; resepectively). The results were supported with thermal and dynamic analyses. At the last stage of the study, the superior thermal conductivity of 0.6220 Wm-1K-1 from the thermal conductivity analysis (TCA), showed that the NR/EPDM blends filled with 3.00 wt. % PEI-treated GNPs exhibited an enhancement in the heat dissipation and thermal-mechanical properties in comparison to the unfilled NR/EPDM blend. In overall, NR/EPDM filled GNPs nanocomposite that was prepared through the combination of an optimized melt-blending processing parameters and amount of MAH compatibiliser with addition of PEI-treated GNPs is able to provide a maximum effects of improved mechanical and thermal properties which is beneficial for the suggested application of rubber component in an automotive engine mount.

ii ABSTRAK

Pada masa kini, nanokomposit polimer telah menarik perhatian ramai disebabkan oleh prestasi amat cemerlang sifat-sifat bahan ini jika dibandingkan dengan polimer tulen atau komposit konvensional. Penyelidikan ini bertujuan menyediakan dan mencirikan sifat mekanik dan terma nanokomposit adunan getah asli (NR) / etilena propilena diena (EPDM) berpengisi kepingan nano zarah grafin (GNPs). Peringkat pertama penyelidikan dimulakan dengan percubaan menyelesaikan isu ketidaklarutcampuran dan ketidakserasian antara fasa getah NR dan EPDM, melalui penggunaan penserasi MAH grafted EPM. Adunan NR/EPDM telah disebatikan dengan menggunakan peralatan pencampur dalaman Haake dan divulkan secara sistem pematangan separa-EV, berdasarkan ASTM D3192. Metodologi permukaan sambutan (RSM) dari perisian Design Expert 6.0.10 telah digunakan, bagi pengoptimuman parameter pemprosesan dan amaun penserasi MAH grafted EPM, terhadap sifat kekuatan tegangan (TS) yang maksimum. Sambutan yang optimum telah diperolehi dari parameter pencampuran NR/EPDM; 110°C suhu pencampuran, 40 rpm kelajuan rotor, 5 minit tempoh pengadunan dan 5 phr amaun penserasi MAH grafted EPM, dengan kebolehulangan yang tinggi dan nilai R2 _sebanyak

~99.00%. Peringkat kedua penyelidikan telah memfokus kepada rawatan permukaan pengisi kepingan nano-zarah grafin secara bukan kovalen, dengan kehadiran polietilenaimina (PEI) dalam medium etanol-air suling (75:25). Mekanisma penjerapan fizikal secara interaksi sterik bukan kovalen GNPs-PEI, telah dicadangkan sebagai mekanisma tindak balas. Pada peringkat ketiga kajian, kesan rawatan permukaan GNPs dan penambahan pengisi yang berbeza (0.25-5.00 bt. %) terhadap kebolehprosesan, sifat mekanik, fizik, terma dan morfologi nanokomposit adalah diselidiki. Rawatan permukaan yang dijalankan keatas GNPs, telah meningkatkan interaksi antara matriks-pengisi dalam nanokomposit adunan getah NR/EPDM. Nanokomposit dengan 3.00 bt. % PEI-terawat GNPs menunjukkan sifat-sifat mekanik yang lebih baik berbanding adunan tidak berpengisi dan adunan berpengisi tidak terawat yang lain (kekuatan tegangan sebanyak 27.78 MPa, 19.65 MPa and 23.34 MPa; masing-masing). Keputusan kajian disokong dengan analisa terma dan dinamik. Pada peringkat terakhir ujikaji, keboleh aliran haba sebanyak 0.6220 Wm-1_K-1 _{menunjukkan adunan NR/EPDM dengan 3.00 bt. % PEI-terawat}

GNPs, telah menunjukkan sifat termal-mekanik yang sangat baik berbanding adunan NR/EPDM tidak berpengisi. Keseluruhannya, penyediaan nanokomposit adunan getah NR/EPDM dengan GNPs menggunakan kombinasi parameter proses penyebatian lebur dan amaun penserasi MAH grafted EPM yang betul, dengan amaun penambahan PEI-terawat GNPs yang optimum, adalah berupaya memberikan kesan sinergistik yang maksimum keatas peningkatan sifat mekanik dan ketahanan haba, yang dilihat sangat berfaedah bagi aplikasi komponen getah pencagak enjin kenderaan automotif sebagaimana yang dicadangkan.

iii

ACKNOWLEDGEMENTS

First of all, my gratitude to Allah S.W.T for giving me the strength to undertake the master’s degree by research sponsored by Ministry of Higher Education through the My Brain 15 (MyMaster) and Fundamental Research Grant Scheme (FRGS).

I would also like to express my sincere gratitude to Universiti Teknikal Malaysia Melaka (UTeM) especially to Centre for Graduate Study (PPS) and Faculty of Manufacturing Engineering (FKP) for giving me the opportunity to further my study. Sincere appreciation to my supervisor, Dr Noraiham Binti Mohamad who has been patiently guiding me throughout the years until the completion of the study. I will remain forever indebted. Thank you so much to my other lecturer and friends, Dr. Jeefferie Bin Abdul Razak, Sharafina, Nadiah, Juliana, khairul Shahril, Anisah, Fevilia, Fariza for their constant help and precious advice on how to pursue the research.

Not forgetting, my deepest regards to all my family, staff and students of Universiti Teknikal Malaysia Melaka (UTeM) as well as staff of Malaysian Nuclear Agency for their support. All the memories will always be treasured in my heart. Last but not least, my highest gratitude and appreciation towards my husband, Mohd Azroy Bin Mohd Razikin who has always been my pillar of strength throughout the course of this study.

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TABLE OF CONTENTS

PAGE DECLARATION

APPROVAL DEDICATION

ABSTRACT i

ABSTRAK ii

ACKNOWLEDGEMENTS iii

TABLE OF CONTENTS iv

LIST OF TABLES vii

LIST OF FIGURES ix

LIST OF APPENDICES xiii

LIST OF ABBREVIATIONS AND SYMBOLS xiv

LIST OF PUBLICATIONS xvi

CHAPTER

1. INTRODUCTION 1

1.1 Research Background 1

1.2 Problem Statement and Significance of Study 5

1.3 Research Objectives 8

1.4 Scope of Research 9

1.5 Thesis Organisation 10

2. LITERATURE REVIEW 11

2.1 Polymer Nanocomposites 11

2.1.1 Polymer Blends as Matrix Materials 14

2.1.2 Reinforcement Materials 17

2.1.3 Processing of Polymer Nanocomposites 18

2.2 Rubber Blends based Nanocomposites 21

2.2.1 Rubber Blends 21

2.2.2 Miscibility and Compatibility 28

2.2.3 Vulcanisation of Rubber Materials 30

2.3 GNPs based Polymer Nanocomposites 35

2.3.1 Mechanical and Thermal Properties of GNPs 36 2.3.2 Aggregation and Agglomeration of GNPs 37 2.4 Mechanical and Thermal Properties of Polymer Nanocomposites 42 3. MATERIALS AND METHODS

3.1 Introduction 45

3.2 Flowchart of Research 45

3.3 Raw Materials 47

3.4 Stage 1: Preparation and Characterisation of NR/EPDM Blends 50

3.4.1 Design of Experiment (DOE) 50

3.4.2 Melt Blending of NR/EPDM blends (ASTM D 3192) 52 3.4.3 Process Evaluation using Cure Characteristic Studies 54 (ASTM D 2084)

v

3.4.5 Mechanical Tensile Testing (BS 6746) 55 3.4.6 Shore-A Hardness Testing (ASTM D 2240-89) 56

3.4.7 Swelling Test (ISO 1817) 57

3.4.8 Thermal Evaluation by Differential Scanning Calorimetry 58 (DSC)

3.4.9 Fracture Morphology Observation by Scanning Electron

Microscopy (SEM) 58

3.4.10 Decision of Processing Parameters 59 3.5 Stage 2: Pre-Treatment of GNPs Prior to Preparation of

NR/EPDM filled GNPs Nanocomposite Blends 60 3.5.1 Surface Modification and Characterisation of Graphene

Nanoplatelets (GNPs) 60

3.5.1.1 Precipitation Analysis of GNPs in Various

Solvents 60

3.5.1.2 Non-covalent Surface Treatment of GNPs 61 3.5.1.3 Fourier Transform Infrared (FTIR) Spectroscopy 62 Analysis

3.5.1.4 X-ray Diffraction (XRD) Analysis 62 3.5.1.5 Transmission Electron Microscopy (TEM) 62 Observation

3.6 Stage 3: Mechanical and Physical Properties of NR/EPDM 63 filled GNPs Nanocomposite

3.6.1 Melt Blending of NR/EPDM filled GNPs Nanocomposite 63 3.6.2 Mechanical and Physical Properties of NR/EPDM 64 filled GNPs Nanocomposite

3.6.2.1 Cure Characteristic Testing (ASTM D 2084) 64 3.6.2.2 Vulcanisation and Sample Fabrication 65 3.6.2.3 Mechanical Tensile Testing (BS 6746) 65 3.6.2.4 Shore-A Hardness Testing (ASTM D 2240-89) 65

3.6.2.5 Swelling Test (ISO 1817) 65

3.6.2.6 X-ray Diffraction (XRD) Analysis 66 3.6.2.7 Fracture Morphology Observation by Field

Emission Scanning Electron Microscopy (FESEM) 3.7 Stage 4: Thermal Properties Evaluation of NR/EPDM 66

GNPs Nanocomposite Blends

3.7.1 Heat Dissipation Study using Thermal Conductivity 66 Analysis (TCA) Test

3.7.2 Heat Degradation Study by Thermogravimetric Analysis 68 (TGA)

3.7.4 Dynamic Properties Study using Dynamic Mechanical 68 Analysis (DMA)

3.8 Summary 68

4. RESULTS AND DISCUSSIONS

4.1 Introduction 70

4.2 Stage 1: Optimum Parameters of NR/EPDM blends via RSM 70

4.2.1 Regression Model 70

4.2.2 Interaction between Variables for Cure Characteristics of 72 the Blends

vi Blends

4.2.4 Interaction between Variables for Hardness Properties of 79 the Blends

4.2.5 Decision for Optimum Processing Parameters 80

4.2.6 Swelling Measurement 81

4.2.7 Differential Scanning Calorimetry (DSC) 82 4.2.8 Scanning Electron Microscopy (SEM) Observation 84

4.2.9 Summary 86

4.3 Stage 2: Analysis of GNPs pretreatment using PEI for the 87 preparation of NR/EPDM filled GNPs nanocomposites

4.3.1 Selection of Dispersant for GNPs by Precipitation Studies 87

4.3.2 FTIR Analysis 91

4.3.3 XRD Analysis 95

4.3.4 Summary 97

4.4 Stage 3: Characterisation studies of NR/EPDM filled GNPs 98 Nanocomposites

4.4.1 Cure Characteristics 98

4.4.2 Tensile Strength 101

4.4.3 Hardness (Shore-A) 104

4.4.4 Swelling Behaviour 105

4.4.5 XRD Analysis 106

4.4.6 FESEM Observation 108

4.4.7 Summary 110

4.5 Stage 4: Thermal Behaviour of NR/EPDM filled GNPs 111 Nanocomposites

4.5.1 Heat Dissipation by Thermal Conductivity Analysis (TCA) 111 4.5.2 Heat Degradation by Thermogravimetric Analysis (TGA) 113 4.5.3 Dynamic Properties Analysis using Dynamic Mechanical

Analysis (DMA) 115

4.5.4 Summary 118

5. CONCLUSION & RECOMMENDATION

5.1 Conclusion 120

5.2 Recommendations for Future Work 123

REFERENCES 124

APPENDICES 136

vii

LIST OF TABLES

TABLE TITLE PAGE

2.1 Classification of Nanofillers; Spherical, Nanotubes and Platelets

19

2.2 Principle Diene Monomer used in EPDM Manufacture 27 2.3 Levels of Sulphur and Accelerator in CV, SEV and EV 35

2.4 Vulcanisate Structures and Properties 35

2.5 Thermal Conductivities of Some Thermally Conductive Fillers

44

3.1 Specification of Purchased GNPs 49

3.2 Levels of Variables 50

3.3 24 _{Factorial Design Matrixes 51}

3.4 The Typical Formulation for Preparation of NR/EPDM Compounds

52

3.5 The Formulation for Preparation of NR/EPDM Filled GNPs Nanocomposites

63

3.6 Fillers Loading 64

4.1 Regression Equations for Each Response Studied 71 4.2 Comparisons of Experimental and Predicted Tensile

Strength Values of NR/EPDM Blends

77

4.3 Criteria for Optimisation of Properties for Melt Blending of NR/EPDM Blends

80

4.4 Tg Values Obtained from DSC 84

4.5 Cure Characteristic Studies for NR/EPDM Rubber Blends Filled with Various Loading of Untreated GNPs and PEI-Treated GNPs

99

4.6 Tensile Properties Values for NR/EPDM Rubber Blends Filled with Pure GNPs and PEI-treated GNPs at Various Filler Loadings

viii

4.7 Thermal Conductivity Values of NR/EPDM Filled GNPs Nanocomposite Blends in respect of Different Blend System at Different Fillers Loading

ix

LIST OF FIGURES

FIGURE TITLE PAGE

2.1 Natural Rubber (Cis 1, 4-polyisoprene) 23

2.2 Polymeric Chain of Rubber 23

2.3 Main Synthetic Rubber Production System 25

2.4 EPM structure 26

2.5 Chemical structure of EPDM 26

2.6 Schematic models of network structure and entanglements in vulcanized and un-vulcanized NR

31

2.7 A Schematic Representation of the Chemistry Involved in the Sulphur Vulcanisation

33

2.8 Influence of Crosslink Density on the Properties of Elastomers

35

2.9 Crosslinking Characteristics of Elastomers Determined from the Torque Measurement

34

2.10 Schematic Illustration of GrapheneNanoplatelets. 36 2.11 Schematic for Particulates, Aggregate and Agglomerate 38 2.12 Graphene Sheets with Strong Covalent and Ionic Bonded

Atoms Held Together by Weak Van Der Waals Forces

38

2.13 Classification of Methods to Disperse Nanofillers in Polymer Resin

39

2.14 Schematic Diagram of the Microstructure of Graphene-Based Nanocomposites based on Monolayer and Trilayer Reinforcements

40

2.15 Schematic of Polymer Nanocomposites Achieving Exfoliation of Nanoplatelets in Polymers Continuous Phase by Assistance of Surface Treatment of Nanoplatelets

43

3.1 Flowchart of the Overall Experiment 46

3.2 The Main Materials used for the Preparation Of NR/EPDM Compounds

x

3.3 The Compounding Chemicals used for the Vulcanisation of the Rubber

48

3.4 The Materials used for Preparation of NR/EPDM Nanocomposites

49

3.5 Haake Internal Mixer 53

3.6 NR/EPDM Blends Dumped from Internal Mixer 53

3.7 The Set Up for Gotech Hydraulic Hot Molding 55

3.8 The as-produced NR/EPDM Vulcanised Sheet after Hot and Cold Molding Operation

55

3.9 Dumbbell Shaped Test Piece 56

3.10 Zwick Roell Hardness Tester 56

3.11 GNPs Dispersion in Organic Solvent Solution 61 3.12 Ultrasonication-Mechanical Stirrer and Freeze Drying

Apparatus Set-Up for GNPs Surface Treatment Procedure

62

3.13 Thermal Conductivity Test Set-Up 67

4.1 3D Response Surface Model Graphs Depicting Variation in Scorch Time, Cure Time, Maximun Torque and Torque Difference as a Function of MAH Grafted EPM and Mixing Time

73

4.2 3D Response Surface Model Graphs Showing Variation in Tensile Strength, Modulus at 100% elongation, Modulus at 500% elongation and Elongation at Break

76

4.3 Plots of the Residuals Vs. Predicted Response for an Error Determination

78

4.4 3D Response Surface Model Graphs Representing Variation in Hardness as a Function of MAH Grafted EPM and Rotor Speed

79

4.5 The Swelling Percentage and Crosslink Density of the NR/EPDM Blends

81

4.6 DSC Thermograms for NR, EPDM, MAH grafted EPM, S0, S1 and S4

83

4.7 Scanning Electron Microscopy Micrographs Showing Tensile Fracture Surface of NR/EPDM Blends at 70/30

xi Blend Ratio

4.8 The GNPs Dispersion in Water and Five Organic Solvents Before Sonication, Dispersion Shortly after Tip Sonication and Dispersion 3 Weeks after Sonication.

89

4.9 TEM Images of GNPs Deposited from Ethanol and THF Suspension

90

4.10 FTIR Spectra of GNPs, PEI and PEI-Treated GNPs 92 4.11 A Schematic Represents the Attachment of PEI on GNPs

Surface

94

4.12 XRD Patterns of Pure GNPs and PEI-Treated GNPs 95 4.13 TEM Image PEI-Treated GNPs Shows Single Layer GNPs

and presence of PEI on the Edges of the GNPs Sheet

96

4.14 The effect of GNPs Loading on the Hardness of NR/EPDM Blends Filled with Pure GNPs and PEI-Treated GNPs

105

4.15 The Effect of GNPs Loading on the Swelling Percentages of NR/EPDM Blends Filled with Pure GNPs and PEI-Treated GNPs

106

4.16 X-ray Diffraction Pattern of Unfilled NR/EPDM blends, NR/EPDM Filled GNPs Nanocomposites and NR/EPDM Filled PEI-Treated GNPs Nanocomposites

107

4.17 Fractured Surface Morphology of Unfilled NR/EPDM Blends, NR/EPDM Blends Filled with 3.00 wt. % PEI-Treated GNPs, and NR/EPDM Blends Filled with 5.00 wt. % PEI-Treated GNPs

109

4.18 Thermal Conductivity Trends for NR/EPDM Filled GNPs Nanocomposite Blends in respect of Different Blend System at Different Fillers Loading

112

4.19 TGA Curves for Unfilled NR/EPDM Blends and NR/EPDM Filled GNPs Nanocomposites

114

4.20 DTG Curves for Unfilled NR/EPDM Blends and NR/EPDM Filled GNPs Nanocomposites

115

4.21 Storage Modulus of Unfilled NR/EPDM Blends and NR/EPDM Filled GNPs Nanocomposites

xii

4.22 Loss Modulus of Unfilled NR/EPDM Blends and NR/EPDM Filled GNPs Nanocomposites

118

4.23 Tan Delta of Unfilled NR/EPDM Blends and NR/EPDM Filled GNPs Nanocomposites

xiii

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Sample of Calculations 135

xiv

LIST OF ABBREVIATIONS AND SYMBOLS

°C - Degree celsius

2D - Two dimensional

6PPD - N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine ANOVA - Analysis of variance

ASTM - American standard testing of materials ATR-FTIR - Attenuated total reflactance-FTIR

CNF - Carbon nanofiber

CNTs - Carbon nanotubes

CO2 - Carbon dioxide

CRI - Cure rate index

DCP - Dicumyl peroxide

DMA - Dynamic mechanical analysis DSC - Differential scanning calorimetry DTG - Derivative thermal gravimetry

E′ - Storage modulus

E′′ - Loss modulus

EB - Elongation at break

EPDM - Ethylene propylene diene monomer EPM - Ethylene propylene copolymer FEA - Finite element analysis

FESEM - Field emission scanning electron microscopy FWHM - Full width at half maximum

GNPs - Graphene nanoplatelets

GPa - Gigapascal

M100 - Modulus at 100% elongation M300 - Modulus at 300% elongation M500 - Modulus at 500% elongation

MAH - Maleic anhydride

xv

Mc - Average molecular weight between crosslink MH-ML - Torque difference

MH - Maximum torque

ML - Minimum torque

MMT - Montmorillonite

Mn - Average number molecule

Mw - Average weight molecule

nm - Nanometer

NR - Natural rubber

NR/EPDM - Natural rubber/ ethylene propylene diene monomer

OH - Hidroxyl

PEI - Polyethyleneimine

PEI-treated GNPs - GNPs treated with polyethyleneimine

phr - Per hundred rubber

PVA - Polyvinyl acetate

RSM - Response surface methodology TMTD - Tetramethylthiuramdisulfide

Qm - Weight increase

υo - Molar volume of toluene

υr - Volume fraction of rubber in swollen sample

χ - Interaction constant characteristic between rubber and toluene

ρ - Density

x - Multiply to

/ - Divide to

= - Equal to

xvi

LIST OF PUBLICATIONS

Journal

1. Jeefferie Abd Razak, Sahrim Haji Ahmad, Chantara Thevy Ratnam, Mazlin Aida

Mahamood, and Noraiham Mohamad. "Effects of poly (ethyleneimine) adsorption

on grapheme nanoplatelets to the properties of NR/EPDM rubber blend nanocomposites". Journal of Materials Science, 50, no. 19 (2015): 6365-6381.

2. Jeefferie Abd Razak, Sahrim Haji Ahmad, Chantara Thevy Ratnam, Mazlin Aida

Mahamood, Juliana Yaakub, and Noraiham Mohamad (2015), Effects of EPDM-g

-MAH compatibilizer and internal mixer processing parameters on the properties of NR/EPDM blends: An analysis using response surface methodology. J. Appl. Polym. Sci., 132, 42199.

3. J. Abd Razak, S. H. Ahmad, C. Thevy Ratnam, M. A. Mahamood, K. T. Lau, H. E. Ab Maulod, R. F. Munawar, N. Mohamad, "Non-Covalent Polymeric Wrapping of IGEPAL C0890 for Graphene Nanoplatelets (GNPs-C0890) Filled NR/EPDM Rubber Blend Nanocomposites", Applied Mechanics and Materials, Vol. 761, pp. 385-390, May. 2015.

4. N. Mohamad, M. A. Mahamood, J. Abd Razak, R. F. Munawar, M. Z. Zainal Abidin, M. A. Azam, M. S. Kasim, M. S. Othman, M. I. Shueb, "Cure Characteristics of Natural Rubber/EPDM Blends for the Effect of MAH Grafted EPM and Compounding Parameters via Response Surface Methodology", Applied Mechanics and Materials, Vol. 761, pp. 441-446, May. 2015.

5. Razak, Jeefferie Abd; Ahmad, Sahrim Haji; Ratnam, Chantara Thevy; Mahamood, Mazlin Aida; Yaakub, Juliana; et al. Graphene Nanoplatelets-Filled NR/EPDM Rubber Blend: Effects Of GNPs Loading on Blend Process Ability, Mechanical Properties and Fracture Morphology. Polymers Research Journal, 9.1 (2015): 43-56.

xvii

6. N. Mohamad, M. A. Mahamood, Y. Juliana, A. R. Jeefferie, A. Muchtar, M. I. Shueb, M. S. Kassim, M. A. Azam, Y. M. Yuhazri, N. Mustafa, A. R. Toibah, T. R. Sahroni, and Q. Ahsan. "Functionalisation of ethylene–propylene copolymer by melt grafting of maleic anhydride using a high shear internal mixer". Materials Research Innovations. 2014; 18(S6), S6-36-S6-42.

7. The Effects of Covalent Treated Graphene Nanoplatelets Surface Modification to Cure Characteristic, Mechanical, Physical and Morphological Properties of NR/EPDM Rubber Blend Nanocomposites, 2014. JA Razak, SH Ahmad, CT Ratnam, MI Shueb, MA Mahamood, J Yaakub, Advances in Environmental Biology 8 (8), 3289-3298.

8. NR/EPDM elastomeric rubber blends miscibility evaluation by two-level fractional factorial design of experiment. Razak, Jeefferie Abd and Ahmad, Sahrim Haji and Ratnam, Chantara Thevy and Mahamood, Mazlin Aida and Yaakub, Juliana and Mohamad, Noraiham, AIP Conference Proceedings, 1614, 82-89 (2014), DOI:http://dx.doi.org/10.1063/1.4895176.

Conference

1. N. Mohamad, M. A. Mahamood, J. Abd Razak, R. F. Munawar, M. Z. Zainal Abidin, M. A. Azam, M. S. Kasim, M. S. Othman, M. I. Shueb, 2013. Cure Characteristics of Natural Rubber/EPDM Blends for the Effect of MAH grafted EPM and Compounding Parameters via Response Surface Methodology. 3rd

International Conference on Design and Concurrent Engineering 2014, 22 and 23 September 2014.

2. N. Mohamad, M. A. Mahamood, Y. Juliana, A. R. Jeefferie, A. Muchtar, M. I. Shueb, M. S.Kassim, M. A. Azam, Y. M. Yuhazri, N. Mustafa, A. R. Toibah, T. R. Sahroni and Q. Ahsan., 2013. Functionalisation of ethylene–propylene copolymer by melt grafting of maleic anhydride using a high shear internal mixer.

International Conference on Science and Engineering of Materials 2013, 13 and 14 November 2013.

1 CHAPTER 1

INTRODUCTION

1.1 Research Background

The emergence of nanomaterials in the area of polymer science and technology have caused nanosized materials to be widely employed in advanced composite systems (Arroyo et al., 2007; Sookyung et al., 2014). The dimension of one of the constituent phase in the composites sometimes can be between 1 to 100 nm, and under these atomic dimensions that particular phase has properties rather different from those of the same material in the bulk form and are referred to as ‗‗nanocomposite‘‘ (Olad, 2011).

Polymer nanocomposites are a type of composite system consisting of two main components; a polymeric matrix material (thermoplastics, thermosets or elastomers) and a nanoscale reinforcing material (nanoparticle) (Koo, 2006). This new class of composite materials have shown enhancement in mechanical properties, thermal stability, chemical resistance, gas permeability and electrical conductivity (Mortensen, 2007; Wu et al., 2013). The property enhancements of polymer nanocomposites are possible with several factors i.e. preparation methods, morphology of the polymer nanocomposites which are dependent on the surface chemistry of each component, type of polymers, as well as characteristics of polymer matrix such as crystallinity, molecular weight and polymer chemistry (Lee et al., 2005). In addition, polymer nanocomposites intend to overcome the drawbacks of polymers through reinforcing effects of the nanofillers while maintaining the natural advantages of the main polymer matrix.

xiii

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Sample of Calculations 135

xiv

LIST OF ABBREVIATIONS AND SYMBOLS

°C - Degree celsius

2D - Two dimensional

6PPD - N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine ANOVA - Analysis of variance

ASTM - American standard testing of materials ATR-FTIR - Attenuated total reflactance-FTIR

CNF - Carbon nanofiber

CNTs - Carbon nanotubes

CO2 - Carbon dioxide

CRI - Cure rate index

DCP - Dicumyl peroxide

DMA - Dynamic mechanical analysis DSC - Differential scanning calorimetry DTG - Derivative thermal gravimetry

E′ - Storage modulus

E′′ - Loss modulus

EB - Elongation at break

EPDM - Ethylene propylene diene monomer EPM - Ethylene propylene copolymer FEA - Finite element analysis

FESEM - Field emission scanning electron microscopy FWHM - Full width at half maximum

GNPs - Graphene nanoplatelets

GPa - Gigapascal

M100 - Modulus at 100% elongation M300 - Modulus at 300% elongation M500 - Modulus at 500% elongation

MAH - Maleic anhydride

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Mc - Average molecular weight between crosslink MH-ML - Torque difference

MH - Maximum torque

ML - Minimum torque

MMT - Montmorillonite

Mn - Average number molecule

Mw - Average weight molecule

nm - Nanometer

NR - Natural rubber

NR/EPDM - Natural rubber/ ethylene propylene diene monomer

OH - Hidroxyl

PEI - Polyethyleneimine

PEI-treated GNPs - GNPs treated with polyethyleneimine

phr - Per hundred rubber

PVA - Polyvinyl acetate

RSM - Response surface methodology TMTD - Tetramethylthiuramdisulfide

Qm - Weight increase

υo - Molar volume of toluene

υr - Volume fraction of rubber in swollen sample

χ - Interaction constant characteristic between rubber and toluene

ρ - Density

x - Multiply to

/ - Divide to

= - Equal to

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LIST OF PUBLICATIONS

Journal

1. Jeefferie Abd Razak, Sahrim Haji Ahmad, Chantara Thevy Ratnam, Mazlin Aida

Mahamood, and Noraiham Mohamad. "Effects of poly (ethyleneimine) adsorption on grapheme nanoplatelets to the properties of NR/EPDM rubber blend nanocomposites". Journal of Materials Science, 50, no. 19 (2015): 6365-6381.

2. Jeefferie Abd Razak, Sahrim Haji Ahmad, Chantara Thevy Ratnam, Mazlin Aida

Mahamood, Juliana Yaakub, and Noraiham Mohamad (2015), Effects of

EPDM-g-MAH compatibilizer and internal mixer processing parameters on the properties of NR/EPDM blends: An analysis using response surface methodology. J. Appl. Polym. Sci., 132, 42199.

3. J. Abd Razak, S. H. Ahmad, C. Thevy Ratnam, M. A. Mahamood, K. T. Lau, H. E. Ab Maulod, R. F. Munawar, N. Mohamad, "Non-Covalent Polymeric Wrapping of IGEPAL C0890 for Graphene Nanoplatelets (GNPs-C0890) Filled NR/EPDM Rubber Blend Nanocomposites", Applied Mechanics and Materials, Vol. 761, pp. 385-390, May. 2015.

4. N. Mohamad, M. A. Mahamood, J. Abd Razak, R. F. Munawar, M. Z. Zainal Abidin, M. A. Azam, M. S. Kasim, M. S. Othman, M. I. Shueb, "Cure Characteristics of Natural Rubber/EPDM Blends for the Effect of MAH Grafted EPM and Compounding Parameters via Response Surface Methodology", Applied Mechanics and Materials, Vol. 761, pp. 441-446, May. 2015.

5. Razak, Jeefferie Abd; Ahmad, Sahrim Haji; Ratnam, Chantara Thevy; Mahamood, Mazlin Aida; Yaakub, Juliana; et al. Graphene Nanoplatelets-Filled NR/EPDM Rubber Blend: Effects Of GNPs Loading on Blend Process Ability, Mechanical Properties and Fracture Morphology. Polymers Research Journal, 9.1 (2015): 43-56.

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6. N. Mohamad, M. A. Mahamood, Y. Juliana, A. R. Jeefferie, A. Muchtar, M. I. Shueb, M. S. Kassim, M. A. Azam, Y. M. Yuhazri, N. Mustafa, A. R. Toibah, T. R. Sahroni, and Q. Ahsan. "Functionalisation of ethylene–propylene copolymer by melt grafting of maleic anhydride using a high shear internal mixer". Materials Research Innovations. 2014; 18(S6), S6-36-S6-42.

7. The Effects of Covalent Treated Graphene Nanoplatelets Surface Modification to Cure Characteristic, Mechanical, Physical and Morphological Properties of NR/EPDM Rubber Blend Nanocomposites, 2014. JA Razak, SH Ahmad, CT Ratnam, MI Shueb, MA Mahamood, J Yaakub, Advances in Environmental Biology 8 (8), 3289-3298.

8. NR/EPDM elastomeric rubber blends miscibility evaluation by two-level fractional factorial design of experiment. Razak, Jeefferie Abd and Ahmad, Sahrim Haji and Ratnam, Chantara Thevy and Mahamood, Mazlin Aida and Yaakub, Juliana and Mohamad, Noraiham, AIP Conference Proceedings, 1614, 82-89 (2014), DOI:http://dx.doi.org/10.1063/1.4895176.

Conference

1. N. Mohamad, M. A. Mahamood, J. Abd Razak, R. F. Munawar, M. Z. Zainal Abidin, M. A. Azam, M. S. Kasim, M. S. Othman, M. I. Shueb, 2013. Cure Characteristics of Natural Rubber/EPDM Blends for the Effect of MAH grafted EPM and Compounding Parameters via Response Surface Methodology. 3rd

International Conference on Design and Concurrent Engineering 2014, 22 and 23 September 2014.

2. N. Mohamad, M. A. Mahamood, Y. Juliana, A. R. Jeefferie, A. Muchtar, M. I. Shueb, M. S.Kassim, M. A. Azam, Y. M. Yuhazri, N. Mustafa, A. R. Toibah, T. R. Sahroni and Q. Ahsan., 2013. Functionalisation of ethylene–propylene copolymer by melt grafting of maleic anhydride using a high shear internal mixer. International Conference on Science and Engineering of Materials 2013, 13 and 14 November 2013.

1 CHAPTER 1

INTRODUCTION

1.1 Research Background

The emergence of nanomaterials in the area of polymer science and technology have caused nanosized materials to be widely employed in advanced composite systems (Arroyo et al., 2007; Sookyung et al., 2014). The dimension of one of the constituent phase in the composites sometimes can be between 1 to 100 nm, and under these atomic dimensions that particular phase has properties rather different from those of the same material in the bulk form and are referred to as ‗‗nanocomposite‘‘ (Olad, 2011).

Polymer nanocomposites are a type of composite system consisting of two main components; a polymeric matrix material (thermoplastics, thermosets or elastomers) and a nanoscale reinforcing material (nanoparticle) (Koo, 2006). This new class of composite materials have shown enhancement in mechanical properties, thermal stability, chemical resistance, gas permeability and electrical conductivity (Mortensen, 2007; Wu et al., 2013). The property enhancements of polymer nanocomposites are possible with several factors i.e. preparation methods, morphology of the polymer nanocomposites which are dependent on the surface chemistry of each component, type of polymers, as well as characteristics of polymer matrix such as crystallinity, molecular weight and polymer chemistry (Lee et al., 2005). In addition, polymer nanocomposites intend to overcome the drawbacks of polymers through reinforcing effects of the nanofillers while maintaining the natural advantages of the main polymer matrix.