FYP Proposal Edited)

8/8/2019 FYP Proposal Edited)

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STUDY OF THE MEDIUM DENSITY POLYETHYLENE MECHANICAL

MILLED WITH THE GRAPHITE POWDER

CHEAH WOI LEONG


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TABLE OF CONTENTS

Pages

TITLE PAGE i

TABLE OF CONTENTS ii

LIST OF TABLES iiiLIST OF FIGURES iv

LIST OF APPENDIX v

LIST OF ABBREVIATIONS vi

CHAPTER 1 INTRODUCTION

1.1 Research Background 1

1.2 Problem Statement 2

1.3 Objectives 2

CHAPTER 2 LITERATURE REVIEW

2.1 Polyethylene-graphite nanocomposite 3

2.2 Graphite 4

2.3 Polyethylene (PE) 4

2.4 Medium Density Polyethylene (MDPE) 6

2.5 Mechanical Milling Method 8


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LIST OF TABLES

Tables No. Page

3.1 Instruments and method 9


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LIST OF FIGURES

Figures No. Page

2.1 Polyethylene chain with side branches 6

3.1 Condition for constructive interference 11

3.2 Sample preparation and etching process 13


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LIST OF APPENDIX

Tables No. Page

A1 commercially produced metallocenes 17

A2 Gantt chart proposal 2010 20


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LIST OF ABBREVIATIONS

Abbreviations

DENT Double Edge Notched Tensile

FNCT Full Notched Creep Tensile

FTIR Fourier Transform Infrared Spectroscopy

HDPE high density polyethylene

IUPAC International Union of Pure and Applied Chemistry

MA Mechanical Alloying

MD Mechanical Disordering

MDPE Medium Density Polyethylenemf mass at the end of temperature, T

MG Mechanical Grinding

ML percentage loss of mass

MM Mechanical Milling

ms mass at the start, before heating

PE Polyethylene

PE100 PE water pipes ISO 4427, an HDPE material

PMC P l M i C i


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CHAPTER 1

INTRODUCTION

1.1 Research Background

Many researchers do relate the conductivity to polymer matrices with respect to the

presence of polymer groups, polymer surface tension and different blends of polymer.

One influencing factor that has not been dealt with is the compatibility of polymer

t i ith d ti fill hi h d h b t ti l ff t d ti it


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diffraction (XRD), Scanning electron microscope (SEM), and Thermogravimetry

(TGA).

1.2 Problem Statement

According to the research of Hamouda et al. (2006). Creep fracture by slow crack

growth is studied in a medium density polyethylene at 60 C and 80 C. Whereas

elasticplastic fracture mechanics load parameters fail to provide a unique

temperature-independent correlation, that of the fracture mechanics for creeping solids

is proved to be relevant since this parameter correlates very well with the time to

failure.

Slow crack growth (SCG) behaviour has been investigated under creep conditions in a

medium density ethylenebutene copolymer (MDPE) on both axisymmetrical Full

Notched Creep Tensile (FNCT) and Double Edge Notched Tensile (DENT) samples

tested at 60 C. Fracture Mechanics for Creeping Solids approach was attempted for

the present medium density polyethylene used for gas-pipe networks. The creep load


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Chapter 2

LITERATURE REVIEW

2.1 Polyethylene-graphite Nanocomposite

This research conducted a mixture of both a new and modified research. The research

will carry out the characterization of the MDPE-graphite composite and determine the

chemical properties and mechanical properties. Some of the researchers have also

t ti t d i th ff t f th th l t i it f h i l


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2.2 Graphite

In recent years, The raw materials most frequently used in graphite manufacturing are

some types of coke, carbon black and natural graphite, which are ground, sieved and

added to a binder. The paste at this stage is homogenized and placed in molds or

passed through drawing frames, sufficiently compacted. The material is then baked

slowly, protected by coke powder, at a temperature of at least 1000 C for complete

elimination of volatile particles from the binder and to transform the remaining

particles into coke.

In principle, graphite is normally classified by grain size. The grain size is used as a

criteria because most of the other properties and characteristics of graphite are related

directly or indirectly to the grain size and orientation. Nowadays, the market offers

graphite classes with average grain sizes under 1m up to 20m.

Due to its low mechanical strength, graphite is considered to be easily machined.

However, complications arise in the cutting of this material due to the layered


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Polyethylene (PE) is a natural, organic, thermoplastic homopolymer which does not

melt at one particular temperature into a clean liquid. Instead it becomes increasingly

soft and ultimately turns into a very viscous, tacky molten mass. It has a low Tg as

strong intermolecular cohesive forces are absent and the substituent group (CH2)

present in it is not bulky. PE is a polymer consisting of long chains of the monomer

ethylene (IUPAC name ethene). Polyethylene is classified into several different

categories based mostly on its density and branching. The mechanical properties of PE

depend on variables such as the extent and type of branching, the crystal structure, and

the molecular weight. (Kosuri et al. , 2008)

Some classifications of PE include:

Ultra high molecular weight PE (UHMWPE)

High density PE (HDPE)

Cross-linked PE (PEX)

Medium density PE (MDPE)

Linear low density PE (LLDPE)

Low density PE (LDPE)


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2.4 Medium Density Polyethylene (MDPE)

Medium-density polyethylene, MDPE, is a semi-crystalline thermoplastic polymer

which has been increasingly used for fabrication of plastic pipes for water and gas

distribution systems. (Peres et al. , 2010)

MDPE viscoelastic characteristics at room temperature, it is susceptible to long term

creep fracture by means of a slow stable crack growth mechanism. (Brown, 2007)

According to the research of Mohammad (2008), he investigated the sole effect of

each parameter and their combination on maximum stress produced in MDPE gas

pipes and their sockets which are made from PE100. MDPE can be used for water

pipe, gas pipe, MDPE plastic pipe and so on. It is known that MDPE pipes offer many

advantages over traditional ductile iron and steel pipes. These advantages include

flexibility, coilability, high ductility, light weight, corrosion resistance, and reduced

installation costs. These features provide both performance and economic benefits

which in turn have made MDPE pipes popular in ploughing-in and trenchless


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Figure 2.1 shows a schematic picture of such a side branching chain; the branches

radiate three-dimensionally, just as the branches of a tree point in all directions from

various places along the trunk. The presence of such side branches is a reason for

variations in a number of important physical properties (such as density, hardness,

flexibility or melt viscosity), which distinguish polyethylene resins. Chain branches

also become points in the molecular network where oxidation may take place. (Wan et

al. , 2006)


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Chapter 3

METHODOLOGY

3.1 Location of research

The research will be conducted at Laboratory of Basic Physics (MFA) in Department

of Physical Sciences, Faculty of Science and Technology, University Malaysia

Terengganu (UMT).


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3.2.2 Characterization

Every 20 hours alternate of ball milling, little grain size of powder will be taken out

and do the characterization by using the X-ray diffraction (XRD) to determine the

crystalline size and using the Scanning electron microscope (SEM) to determine the

graphite morphology.

3.2.3 Compounding process (composite)

In this process, MDPE will mix with the graphite by using the HAAKE Polylab

system. The blending process will carry out 5 samples; each sample will use 0wt%,

1wt %, 2wt%, 3wt%, 4wt% mix with the MDPE. The materials were compounded

into different mixture ratios of graphite content in MDPE. The MDPE will compound

at 180 and 170RPM for 20 min. Firstly, the MDPE will add to the mixer until the

MDPE fully melt and be liquid, and then the graphite powder is added until the

mixing torque become stabilized.


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3.2.5 Analysis

Lastly, MDPE-graphite composite be produced. Testing and analysis were perform on

this stage. Table below shows several characterizations method and description in this

research.

Table3.1 : Instruments and method

Method Description

Thermogravimetry (TGA) Determine change of weight in relation of

the change of temperature

X-ray diffraction (XRD) Investigation of the fine structure of matter

Fourier Transform InfraredSpectroscopy (FTIR)

Determine the type of bonds which arepresent in a compound

Testometric MODEL 350/500 Tensile test

Four Point Probe Determine the conductivity

3 3 I t t


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ML =msmf

ms 100%

TGA measurements were carried out in a TGA 6 Perkin-Elmer analyzer under a

nitrogen atmosphere. Around 10 mg of sample was used. The measurements were

performed from 50-800C at a heating rate of 10C/ min. (Kosuri et al. , 2008)

3.3.2 X-Ray Diffraction

X-ray diffraction is a tool for the investigation of the fine structure of matter. This

technique had its beginnings in von Laues discovery in 1912 that crystals diffract

Xrays, the manner of the diffraction revealing the structure of the crystal. At first, x-

ray diffraction was used only for the determination of the crystal structure. Later on,

however, other uses were developed and today the method is applied not only to

structure determination but to such diverse problems as chemical analysis and stress

measurement, to the study of phase equilibria and the measurement of particle size, to

the determination of the orientation of one crystal or the ensemble of orientations in

polycrystalline aggregate.

(3.1)


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Braggs law states the essential condition which must be met if diffraction is to occur.

N is called the order of reflection, it may take on any integral value consistent with

sin not exceeding unity and is equal to the number of wavelengths in the path

difference between rays scattered by adjacent planes. Therefore, for fixed values of

and d, there may be several angles of incidence 1, 2, 3 at which the diffraction

may occur corresponding to n=1,2,3

Debye Scherrers formula is used to calculate the crystallite lamella size. Scherrers

equation is given as Crystallite Lamella size= 0.9 /(B cos ) Where, B is ful l width

half maxima in nm. (Kosuri et al. ,2008)

3.3.3 Fourier Transform Infrared Spectroscopy (FTIR)

Fourier transform infrared spectroscopy is another form of infrared spectroscopy

which does not bombard the samples using infrared radiation of individual

wavelengths. Instead, FTIR uses sends out a pulse of beam which contains the

information of all infrared wavelengths. The beam is transmitted through the sample,

and the transmitted beam results in an interferogram. The interferogram is then


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3.3.4 Testometric Model 350/500

Testometric Model 350/500 design and manufacture a comprehensive range of

materials testing machines and software for evaluating the mechanical properties and

performance of materials. It has two type of this model, there are AT range of stand-

alone universal strength testing machines and the CT range of universal strength

testing machines. Testometric machine can done the testing including tensile test, wet

strength and puncture of tissue, board tests include flat, ring edge and the etc.

Accessories for paper testing include a wide range of grips and fixtures for paper

testing and all are compliant to international standards.

3.3.5 Four Point Probe

Four point probes method is a simple apparatus for measuring the resistivity of

semiconductor samples. By passing a current through two outer probes and measuring

the voltage through the inner probes allows the measurement of the substrate

resistivity. The sheet resistivity of the top emitter layer is very easy to measure


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3.4 Process Flow Chart

Preparation of samples-mill graphite (20, 40, 60, 80,100 hr)

Characterization graphite

SEM

XRD

Compounding process

MDPE

MDPE

+

1wt%

graphite

MDPE

+

2wt%

graphite

MDPE

+

3wt%

graphite

MDPE

+

4wt%

graphite


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Chapter 4

EXPECTED RESULTS

Graphite transforms to an amorphous phase by ball milling, the average size reachfrom 3nm to 8nm after 60 hour milling.

When MDPE mix with the graphite, crystallinity will increase and structure will be

more close packing. When crystallinity increases, hardness will increase. Tensile

d l i i f 1 9 3 2 G h il h ill i f 16


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REFERENCES

Peres, M. F. , Schn, C.G. & Tarpani, J.R. 2010 Effect of precracking method on KIcresults for medium-density polyethylene tested under cryogenic condition.

Journal of Polymer Testing 29 : 667673

Brown, N. Intrinsic lifetime of polyethylene pipelines. 2007. Polymer Engineering

and Science. doi:10.1002/pen :477480

Mohammad Shishesaz1 & Mohammad Reza Shishesaz . 2008. Applicability of

Medium Density Polyethylene Gas Pipes in Hot Climate Areas of South-west

Iran. Iranian Polymer Journal. 17 (7), 503-517

Zhang , W. , Dehghani-Sanij , A. A. & Blackburn, R.S. 2007 Carbon based

conductive polymer composites.J Mater Sci. 42: 34083418


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Wolak, J. E. 2005. Polyolefin miscibility: Solid-state NMR investigation of phase

behavior in saturated hydrocarbon blends. Dissertation Degree of Doctor of

Philosophy. North Carolina State University.

Dhoot, S.N. , B.S. & M.S. 2004. Sorption And Transport Of Gases And Organic

Vapors In Poly(Ethylene Terephthalate). Dissertation Degree of Doctor of

Philosophy. University of Texas, Austin.

Suryanarayana, C . 2001. Mechanical alloying and milling. Journal of Progress in

Materials Science, 46: 1-184

Wan Aizan & Rahman, W.A. 2006. Design of silane crosslinkable high density

polyethylene compounds for automotive fuel tank application. Thesis of

project IRPA. Faculty of Chemical and Natural Resource Engineering,

Universiti Teknologi Malaysia


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APPENDIX

Table A1: commercially produced metallocenes


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20

Table A2: Gantt Chart for FYP

No. Task

Month

2010 2011

JUL AUG SEP OCT NOV DEC JAN FEB MAR APR

1 Literature Review

2 Title Selection & Submission

3 Writing Proposal

4 Proposal Submission

5 Proposal Presentation

6 Lab work 1 (Preparation)

7 Lab work 2 (Compounding)

8 Writing Progress Report 1

9 Writing Progress Report 2

10 Thesis Writing

11 Submit Final Draft

12 Final Presentation

13 Thesis Submission

FYP Proposal Edited)

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