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EFFECT OF MOISTURE CONTENT (HYGRIC) ON THE MECHANICAL PROPERTIES FOR DIFFERENT FIBRE VOLUME FRACTIONS OF DONAX GRANDIS NATURAL

FIBRES REINFORCED UNSATURATED POLYESTER COMPOSITES

Chieng Yew Kai

TA

418.9 C6

C532 2005

Bachelor of Engineering with Honours

(Mechanical Engineering and Manufacturing Systems)

2005

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BORANG PENYERAHAN TESIS

Judul: Effect Of Moisture Content (Hyari) On The Mechanical Properties For Different Fibre Volume Fractions Of Donax Grandix Natural Fibres Reinforced Unsaturated Polyester Composites.

SESI PENGAdIAN : 2004/2005

Saya CHIENG YEW KAI mengakui membenarkan tesis ini disimpan di Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dengan syarat-syarat kegunaan seperti berikut:

1. Hakmilik kertas projek adalah di bawah nama penulis melainkan sebagai projek bersama clan dibiayai oleh Universiti Malaysia Sarawak, hakmiliknya adalah kepunyaan Universiti Malaysia Sarawak.

2. Naskah salinan di dalam bentuk kertas atau mikro hanya boleh dibuat dengan kebenaran bertulis daripda Universiti Malaysia Sarawak atau penulis.

3. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan untuk pengajian mereka.

4. Kertas projek hanya boleh diterbitkan dengan kebenaran penulis atau Universiti Malaysia Sarawak. Bayaran royalti adalah mengikut kadar yang dipersetujui kelak.

5. * Saya membenarkan / tidak membenarkan Perpustakaan membuat salinan kertas projek ini sebagai bahan pertukaran di antara institusi pengajian tinggi.

6. * tandakan (/) di mana kotak yang berkenaan E: 1

(Mengandungi maklumat yang berdarjah keselamatan atau SULIT kepentingan Malaysia seperti yang termaktub di dalam AKTA

RAHSIA RASMI 1972).

TERHAD

(Mengandungi maklumat TERHAD yang telah ditentulan oleh organisasi / badan di mana penyelidikan dijalankan).

TIDAK TERHAD

(TANDATANGAN PENULIS)

15A, JLN. Rejang, Alamat tetap: Liang Vit Garden,

96100 Sarikei, Sarawak.

Catatan *

**

PUAN MAHSHURI YUSOF

Potong yang tidak berkenaan.

Jika Kertas Projek ini SULIT atau TERHAD, sila lampirkan surat daripada pihak / organisasi berkenaan dengan menyertakan sekali tempoh kertas projek. Ini perlu dikelaskan sebagai SULIT atau TERHAD.

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APPROVAL SHEET

This project report, which entitled "Effect Of Moisture Content (Hygric) On The Mechanical Properties For Different Fibre Volume Fractions Of Donax Grandis Natural Fibres Reinforced Unsaturated Polyester Composites" was prepared by Chieng Yew Kai as a partial fulfillment for the Bachelor's Degree of Engineering with Honours (Mechanical Engineering and Manufacturing System) is hereby read and approved by:

Date:

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Madam MKshuri Yusof Project Supervisor

Faculty of Engineering

Universiti Malaysia Sarawak

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Pusat Khidmat Mlfclumat Akademik UNIVERSITY MALAYSIA SARAWAY

9410n Kota Samarahan

EFFECT OF MOISTURE CONTENT (HYGRIC) ON THE MECHANICAL

PROPERTIES FOR DIFFERENT FIBRE VOLUME FRACTIONS OF DONAX GRANDIS NATURAL FIBRES REINFORCED UNSATURATED

POLYESTER COMPOSITES.

P. KHIDMAT MAKLUMAT AKADEMIK U NIMAS

hIIIIIIIIIIIIIItlIIIINI

1000132362

By

CHIENG YEW KAI

This project is submitted in partial fulfillment of the requirement for the degree of Bachelor of the Engineering with Honours (Mechanical Engineering and

Manufacturing Systems)

UNIVERSITI MALAYSIA SARAWAK 2005

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Dedicated to my beloved family and friends those always support me

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ACKNOWLEDGEMENT

I would like to take this opportunity to give my sincere acknowledgement to several individual and parties that giving me a lot of helps and guidance throughout the period towards completing my final year project.

First of all, great appreciation to my project supervisor, Madam Mahshuri Yusof, who had not only giving me a lot of valuable guidance and opinion but also help me in experiment's hardware preparation in conducting the experiment and writing this report.

Besides, I also want to thanks to Universiti Malaysia Sarawak, all lectures of Engineering Faculty, supporting staffs and friends who had also helped me either directly or indirectly in of raw material purchasing (Donax Grandis), information gathering and opinion provision. In addition, I would like to specifically thanks all the staffs of Sarawak Timber Research Centre who had not only allowing me to use the facilities at there but also given full support to me.

Lastly, I also thanks to my family and friends for giving their support, help an encouragement during the drift and difficult encounters while doing this project.

Chieng Yew Kai

Universiti Malaysia Sarawak 2004/05

111

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ABSTRACT

Donax Grandis or also called as "Bemban" natural fibre was combined with unsaturated polyester resin matrix in order to produce the advance structural composite. The type of Donax Grandis plant used in this study is originated from

lowland forest which is easily available in Malaysia. The ages of Donax Grandis consumed was around 5 to 6 months which is believed already achieving their maturity stage. Biological retting was used to extract the natural fibres where the thin layer of skins or bundle have been separated from stems and boiled prior to submerge into the lake (water + soil) for 2 months. The purpose of this method is to accelerate the activity of the bacterial in break down the pectin content. The Donax Grandis

natural fibres were well incorporated in the unsaturated polyester resin matrix and successfully hot-press to become laminae. Unidirectional composites with 40% and 60% fibre volume fraction were fabricated. The maximum moisture or hygric saturation effect of these composites was evaluated in term of their mechanical properties. Hence, a number of tests were carried out, namely, tensile test upon both dried and moisture affected longitudinal and transverse unidirectional composites, and also compression test upon both dried and moisture affected longitudinal unidirectional composites according to parameters specified by the respective ASTM.

Donax Grandis natural fibres reinforced unsaturated polyester composites possess high modulus and strength in both tensile and compression properties. The moisture effect had been proven would degrade the mechanical properties of these composites.

Keywords: Donax Grandis, unsaturated polyester, moisture or hygric effect.

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ABSTRAK

Gentian semula jadi dari Donax Grandis atau juga dikenali sebagai "Bemban"

telah digunakan untuk bergabung dengan polyester tak tepu bagi menghasilkan struktur komposit yang canggih. Tumbuhan Donax Grandis yang digunakan dalam kajian ini berasal dari habitat hutan tanah rendah yang mudah didapati di seluruh Malaysia. Umur Donax Grandis ini adalah di lingkungan 5 hingga 6 bulan dan dipercayai sudah mencapai tahap kematangannya. Kaedah pereputan secara biologi digunakan untuk mengeluarkan gentian dengan cara memisahkan lapisan kulit yang nipis dari batangnya dan dididihkan sebelum direndamkan dalam tasik (air + lumpur) selama 2 bulan. Tujuannya ialah untuk mempercepatkan aktiviti tindakan bakteria bagi melumpuhkan kandungan pectin. Gentian semula jadi Donax Grandis dapat bergabung secara sempurna dengan polyester tak tepu setelah ditekan and dipanaskan bagi menghasilkan lapisan lamina Komposit sehala dengan 40% and 60% kandungan fiber telah dihasilkan. Kesan daripada penyerapan kelembapan yang masimum terhadap komposit ini telah diuji dari segi ciri - ciri mekanikalnya. Maka, beberapa ujian telah dijalankan. Antaranya ialah ujian tarikan ke atas kedua-dua komposit menjalur dan melintang sehala yang dikeringkan dan juga yang dibasahi, serta ujian mampatan ke atas kedua dua komposit menjalur sehala yang dikeringkan dan yang dibasahi dengan mengikut peraturan yang ditetapkan oleh ASTM tertentu. Komposit ini mempunyai nilai moduli dan ketegangan yang tinggi terhadap tarikan dan tekanan yang dikenakan. Adalah terbukti bahawa penyerapan kelembapan oleh composit ini telah menjatuhkan ciri - ciri mekanikalnya.

Kata kunci: Donax Grandis, unsaturated polyester, kesan penyerapan kelembapan.

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LIST OF TABLES

TABLE DESCRIPTION

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PAGE

2.1 Relative Proportions of the Major Constituents and Properties of 9 Some of the Common Natural Fibres.

2.2 Properties of Asbestos Fibres. 9

2.3 Properties of Synthetic Fibres. 10

2.4 Properties of Selected Matrix Materials. 14

2.5 Properties of Selected Thermosetting and Thermoplastic 15 Matrixes.

2.6 Typical Room Temperature Properties of Polymer Resins 22 Selected.

3.1 Curing Characteristics of Each Type of Polymer Resin With the 47

Hardener Used.

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3.2 Dimensions of Each Composite Lamination as Specified by 48 ASTM D3039 - 76 (1989).

3.3 Dimensions of the Compression Test Specimen as Specified by 49 ASTM D-3410-87.

3.4 Specifications of the Tabs Used in Both Governed Standards. 50

3.5 Numbers of Test Specimens Prepared According to the Type of 51 Lamination Pattern and Resin Used.

5.1 Mechanical Properties In Term of Modulus Young, Tensile 92 Strength and Compression Strength Obtained From Moisture

Saturated or Hygric Affected Composites With Respect to Their Fibre Volume Fraction.

5.2 Mechanical Properties In Term of Modulus Young, Tensile 93 Strength and Compression Strength Obtained From 100% Dried

Composites With Respect to Their Fibre Volume Fraction.

5.3 Mechanical Properties In Term of Ultimate Strain Achieved 93 From Both Moisture Saturated or Hygric Affected Composites

and 100% Dried Composites With Respect to Their Fibre Volume Fraction.

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LIST OF FIGURES

FIGURE DESCRIPTION

NO.

1.1 Reinforcement Form; (a). Continuous Fibres; (b). Discontinuous

PAGE

Fibres, Whiskers; (c). Particles; (d). Fabrics, Braid, etc. 2

1.2 Basic Fibres Lamination Approach; (a). Uniaxial, (b). 3 Multiaxial, (c). Orthogonal.

1.3 The Cell - Structure of A Natural Composite, A Tree. 4

1.4 Natural Fibers (Flax, Kenaf, Jute and Even Chicken Feathers) 6 are Viable Candidates for Fiber Reinforcements.

2.1 Stress-Strain Curves for A Range of Fibres.

2.2 Specific Strength Versus Specific Modulus.

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2.3 (a). Donax Grandis Plant; (b). Its Stem; (c). Its Inner Core; (d). 12-13 Bunch of Stem.

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2.4 Effects of Internal Stress on the Measured Water Uptake of A 25

Graphite / Thermoplastic.

2.5 Effect of Coupling Agent on the Strength of Epoxy Laminates 28 as A Function of Time Exposed to Boiling Water. Volan A,

Methacrylatochromic Chloride; A-1100, Triethoxysiyl Propylamine; Z-6040, Glycidoxypropyl Trime-Ethoxysilane; Y- 4086,3,4-Eposycyclohexylethyl Trimethoxysilane.

2.6 Hydrolysis of the Covalent M-O In Presence of the Water; (b). 28 Shear Displacement At the Polymer-Glass Interface Without

Permanent Bond Rupture.

2.7 Hygric Strains In Unidirectional AS4/3501-6 Carbon / Epoxy 33 Composite as A Function of Moisture Concentration.

2.8 Relation Between Strain and Deformation. 35

2.9 (a). Stress - Strain Relation In Tension; (b). Stress - Strain 36 Relation In Compression.

2.10 (a). Longitudinal Tensile Strength; (b). Transverse Tensile 37 Strength.

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2.11 (a). Longitudinal Compression Strength; (b). Transverse 39 Compression Strength.

3.1 (a). Separate the Skin From Inner Core; (b). Submerge the 43 Separated Parts Into the Lake.

3.2 (a). Drying the Tow of Fibre In Force Air Concentration Oven; 43 (b). Periodically Weight Measurement of the Tow of Fibre

During Drying Process.

3.3 Composite Lamination Types Chosen; (a). Longitudinal 44 Unidirectional; (b). Transverse Unidirectional.

3.4 Fibre - Reinforcement Lamination Process.

45

3.5 Specimen Geometries for Determination of Tensile Properties 48 of Unidirectional Lamina; (1). Longitudinal; (2). Transverse.

3.6 Dimensions of the Compression Test Specimen; (a). Side View, 49 (b). Plane View.

3.7 Cutting of the Individual Specimens of Desired Width From the 52

Tabbed Specimens.

3.8 Testometric 53

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3.9 Tensile Test Specimen Geometry According to the ASTM 55 D3039 Specification; (a). Side View; (b). Plane View.

3.10 Tensile Test Specimen Fixture or Gripper. 55

3.11 Compression Test Specimen Geometry According to the ASTM 58 D3410 Specification; (a). Side View; (b). Plane View.

3.12 Compression Test Specimen Fixture or Gripper. 58

4.1 Graph Shows the Linear Slope of Volume - Mass Curve as the 62 Experimental Results for Density of Donax Grandis Natural

Fibre With 2.2% of Deviation In Calculation.

4.2 Graph Showing Moisture Absorption of the Specimens With; 64 (a). 60% Fibre Volume Fraction; (b). 40% Fibre Volume

Fraction.

4.3 Stress - Strain Curve for Tensile Test on 60% and 40% Fibre 68 Volume Fraction Wet Longitudinal Unidirectional Specimen.

4.4 Stress - Strain Curve for Tensile Test on 60% and 40% Fibre 69 Volume Fraction Wet Transverse Unidirectional Specimen.

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4.5 Failure Sequence In Unidirectional Composite With Fibre - 70 Dominated Strength Under Longitudinal Tensile Loading.

4.6 Stress - Strain Curves for Tensile Test of 60% Fibre Volume 73 Fraction Wet Longitudinal and Transverse Unidirectional

Specimen.

4.7 Stress - Strain Curve for Tensile Test of 40% Fibre Volume 73 Fraction Wet Longitudinal and Transverse Unidirectional

Specimen.

4.8 Local Stress In Transversely Loaded Unidirectional Composite. 75

4.9 Progressive Microcracking Leading to Ultimate Failure In 76 Unidirectional Composite Under Transverse Tension.

4.10 Stress - Strain Curve for Compression Test o 60% and 40% 77 Fibre Volume Fraction Wet Longitudinal Unidirectional

Composite.

4.11 Microbuckling Modes In A Unidirectional Composite Under 78 Longitudinal Compression. (a). Out - Of - Phase or Extensional

Mode. (b). In - Phase or Shear Mode.

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4.12 (a). Microbuckling Leading to Formation of Kink Zones With 79 Excessive Deformation of Fracture Planes for ductile Fibres (b)

or Brittle Fibres (c).

4.13 Microbuckling Which Led to Formation of Kink Zones With 79 Excessive Deformation of Fracture Planes for Compression Test

Upon the Donax Grandis Natural Fibre Unsaturated Polyester Reinforced Composite.

4.14 Stress - Strain Curve for Tensile Test on 60% and 40% Fibre 81 Volume Fraction Dry Longitudinal Unidirectional Composite.

4.15 Stress - Strain Curve for Tensile Test on 60% and 40% Fibre 81 Volume Fraction Dry Transverse Unidirectional Composite.

4.16 Stress - Strain Curve for Tensile Test on 60% Fibre Volume 83 Fraction Dry Longitudinal and Transverse Unidirectional

Composite.

4.17 Stress - Strain Curve for Tensile Test on 40% Fibre Volume 84 Fraction Dry Longitudinal and Transverse Unidirectional

Composite.

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4.18 Stress - Strain Curve for Compression Test of 60% and 40% 86 Fibre Volume Fraction Dry Longitudinal Unidirectional

Composite.

4.19 Tensile Strength of Longitudinal Unidirectional Donax Grandis 87 Natural Fibres - Unsaturated Polyester Composites.

4.20 Tensile Strength of Transverse Unidirectional Donax Grandis 87 Natural Fibres - Unsaturated Polyester Composites.

4.21 Compressive Strength of Longitudinal Unidirectional Donax 88 Grandis Natural Fibres - Unsaturated Polyester Composites.

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ABBREVIATIONS

T. Shear stress

EP Epoxy

PEEK Polyetheretherketone

MPa Mega Pascal

hr Hour

Tg Transition temperature

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M m N

C

vi dill

Coefficient of moisture expansion Relative weight gain

Meter

Newton

Average moisture concentration

VW V VIUIIIGJ VI WaLGl

V. Volume of composite

WW Weight of water

W0 Weight of composite pW Density of water

P.

Density of composite

UTS Material ultimate strength

GREs Glass fibre-reinforced epoxies

t Time

D Diffusion coefficient

x Distance

h Plate thickness

nos. Number

Vf Fibre Volume Fraction Vm Matrix Volume Fraction

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Chapter 1 Introduction

CHAPTER 1 INTRODUCTION

1.1 Introduction

Composites are important materials that are now used widely, not only in the aerospace and military industry, but also in a large and increasing number of commercial mechanical engineering applications. For instance, car body cover, bicycle body structure and leisure equipments. Hence, the development of composite

materials and related design and manufacturing technologies is one of the most important advances in the history of materials.

Generally, composites tend to have the characteristics such as high strength;

high modulus; low density; excellent resistance to fatigue, creep, creep rupture, corrosion, and wear; and low coefficient of thermal expansion (CTE). However, many artificial composites, especially those reinforced with fibres, are anisotropic, which

means their properties vary with direction (the properties of isotropic materials are the same in every direction). Figure 1.1 shows the main types of reinforcements used in composite materials: aligned continuous fibres; discontinuous fibres, whiskers (elongated single crystals); particles; and numerous forms of fibrous architectures

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Chapter 1 Introduction

produced by textile technology, such as fabrics and braids. Increasingly, hybrid composites that combine different types of reinforcements are developed in term to achieve more efficiency and to reduce cost.

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Figure 1.1: Reinforcement Form; (a). Continuous Fibres; (b). Discontinuous Fibres, Whiskers; (c). Particles; (d). Fabrics, Braid, etc.

(Zweben, 1998)

Bader (2002) has stated that the fibres are typically of the order 10 pm in diameter which is about half of a human hair, but some are less than 5µm and others may up to 150 pin. Mallick (1993) has define the fibre-reinforced composites materials as the advanced material that consist of fibres of high strength and modulus embedded in or bonded to a matrix with distinct interfaces (boundary) between them.

In this form, both fibres and matrix retain their physical and chemical identities, yet they produce a combination of properties that cannot be achieved with either of the

EFFECT OF MOISTURE CONTENT (HYGRIC) ON THE ... - unimas ir

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EFFECT OF MOISTURE CONTENT (HYGRIC) ON THE MECHANICAL PROPERTIES FOR DIFFERENT FIBRE VOLUME FRACTIONS OF DONAX GRANDIS NATURAL

FIBRES REINFORCED UNSATURATED POLYESTER COMPOSITES

Chieng Yew Kai

Bachelor of Engineering with Honours

(Mechanical Engineering and Manufacturing Systems)

2005

APPROVAL SHEET

ý C) lS!

hIIIIIIIIIIIIIItlIIIINI

ACKNOWLEDGEMENT

ABSTRACT

ABSTRAK

Kata kunci: Donax Grandis, unsaturated polyester, kesan penyerapan kelembapan.

TABLE OF CONTENTS

LIST OF TABLES

Hardener Used.

LIST OF FIGURES

2.4 Effects of Internal Stress on the Measured Water Uptake of A 25

45

3.7 Cutting of the Individual Specimens of Desired Width From the 52

ABBREVIATIONS

0

P.

CHAPTER 1

INTRODUCTION