i

TITLE

PRODUCTION AND CHARACTERIZATION OF PLASTIC FROM

MARINE ALGAE

RAMANAN A/L NADARAJAN

Thesis submitted in fulfillment of partial requirements

for the award of degree of Bachelor of Chemical Engineering

Faculty of Chemical and Natural Resources Engineering

UNIVERSITI MALAYSIA PAHANG

JANUARY 2013

ii

SUPERVISOR’S DECLARATION

“I hereby declare that I have read this thesis and in my opinion this thesis has

fulfilled the qualities and requirements for the award of Degree of Bachelor of

Chemical Engineering”

Signature : _________________________________

Name of Supervisor : DR. MOHAMMAD DALOUR HOSSEN

BEG

Position : SENIOR LECTURER

Date : 24 JANUARY 2013

iii

STUDENT’S DECLARATION

I declare that this thesis entitled “Production and Characterization of plastic from

Marine Algae” is the result of my own research except as cited in references. The

thesis has not been accepted for any degree and is not concurrently submitted in

candidature of any other degree.”

Signature : _____________________________

Name : RAMANAN A/L NADARAJAN

ID Number : KA09072

Date : 24 JANUARY 2013

iv

To my beloved family and friends

v

ACKNOWLEDGEMENTS

I would like to express my humble gratitude to my supervisor, Dr.

Mohammad Dalour Hossen Beg who have supervised and supported me throughout

the entire process of this research with his patience and knowledge whilst allowing

me to work on my own pace. Endless guidance was given by him to push myself to

become a better researcher and also as a future engineer. One could not have had a

friendlier supervisor.

Next, I also would like to express my gratitude towards Mr. Reman for his

guidance, suggestions, co-operations and supports in running the research.

Special thanks to Faculty of Chemical & Natural Resources Engineering,

University Malaysia Pahang (UMP), especially the lecturers, administrative staffs

and laboratory assistants, for the help and advises, and to those who involves directly

or indirectly in the completion of my project.

Lastly, I would like to thank all my family and friends who deserve a token of

appreciation for the support that enabled me to successfully finish this thesis.

vi

TABLE OF CONTENT

Title Page

No.

Cover Page i

Supervisors Declaration ii

Students Declaration iii

Acknowledgement v

Table of Content vi

List of Figures viii

List of Tables xi

List of abbreviations xii

Abstract xiii

Abstrak xiv

1.0 Introduction 1

1.1 Background of Study 1

1.2 Problem Statement 6

1.3 Research Objective 6

1.4 Scope of Study 7

1.5 Significance of Study 7

1.6 Conclusion 8

2.0 Literature Review 9

2.1 Introduction 9

2.2 Marine Algae 10

2.3 Low Density Polyethylene 15

vii

2.4 Structural Modification 18

2.5 Polymer Blending 21

2.6 Polymer Characteristics 22

2.7 Conclusion 25

3.0 Methodology 27

3.1 Introduction 27

3.2 Processing Flow Chart 28

3.3 Materials 29

3.4 Equipments 29

3.5 Method of Research 33

4.0 Results and Discussions 35

4.1 Introduction 35

4.2 Extrusion Process 37

4.3 Hot Press: Parameter Optimization 38

4.4 Differential Screening Calorimeter (DSC)

and Thermo gravimetric Analyser (TGA 41

4.5 Tensile Testing 45

4.6 Water Absorption Test 48

4.7 Conclusion 49

5.0 Conclusion and Recommendations 51

5.1 Conclusions 51

5.2 Recommendations 51

Reference 53

Appendix 54

viii

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Chemical structure of the repeating dimeric 3

units of λ-carrageenan

1.2 Chemical structure of the repeating dimeric 4

units of fucoidal

2.1 Molecular structures of marine algae extract 11

2.2 Enzymatic modifications of amylase and 19

amylopectine with amylomaltase

2.3 FTIR analyses Peaks 23

2.4 DSC analysis peaks 24

2.5 TGA Analysis diagram 25

4.1 Plastic Blend 5%, 10%, 15%, and 20% 36

for top left to bottom right

4.2 Graph of Tensile strength vs. Temperature 39

4.3 Graph of Tensile Strength vs. Time 39

4.4 Mould (top), Dog bone testing sample (bottom) 40

4.5 : DSC Profile for 5% of algae 41

4.6 Graph of Melting Point vs. Algae Composition 42

4.7 Graph of Glass Transition Temperature vs. 43

Algae Composition

ix

4.8 TGA profile for 5% algae composition 44

4.9 TGA profile for 20% algae composition 45

4.10 Graph of Tensile Strength vs. algae composition 47

4.11 Graph of Elongation vs. Algae Composition 48

4.12 Graph of Water Absorbance vs. Composition 48

x

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 Proteins in algae 14

3.1 blending composition of samples in % and grams 34

4.1 Hot Press Temperature optimization 38

4.2 Hot Press Time Optimization 39

4.3 Glass Transition Temperature and 42

Melting Temperature from DSC test

4.4 Tensile Strength and Elongation at Break profile 46

for varying algae composition

4.5 Water absorption profile with varying 48

algae composition

xi

LIST OF ABBREVIATIONS

DSC Differential Screening Calorimeter

EVA Ethylene Vinyl Acetate

FE Formaldehyde Emission

FTIR Fourier Transform Infrared spectroscopic

HDPE High Density Poly Ethylene

LDPE Low Density Poly Ethylene

NP Natural Pigment

OSB Oriented Strand Board

PP Polypropylene

RTV Room Temperature Vulcanizing

SEM Scanning Electron Microscopic

TGA Thermo-gravimetric Analyser

UV/V Ultra-violet Visible Spectrophotometer

xii

LIST OF SYMBOLS

C Degree Celsius

% Percentage

MPa Mega Pascal

USD United States Dollar

RM Ringgit Malaysia

Tons Tonnes

$ Dollar

pH Power of Hydrogen

˚F Degree Fahrenheit

g/cm3 Gram per centimeter cube

µm Micro meter

mm Millimeter

M Molarity

V Volume

mL Milli-Liter

g Gram

h Hour

cP Centipoises

wt. Weight

s Second

xiii

PRODUCTION AND CHARACTERIZATION OF PLASTIC FROM

MARINE ALGAE

ABSTRACT

The two main objective of this research is to test the viability of using marine

algae as a profound bio-filler for the production of plastic where the plastic produce

will have the tendency to reduce usage of non-renewable recourse which contributes

to severe ecological problems. The second objective is to characterize the plastic

blend produced using marine algae via physical, mechanical and thermal testing. In

this study, Marine algae and Low density polyethylene is used as raw material and

blended to produce plastic sample which later on was characterized using

Differential Scanning Calorimeter (DSC), Thermogravimetry Analyzer (TGA), and

tensile tester as well as water absorption tests. The results concluded that these red

marine algae are not suitable for plastic production without any modification. This is

due to the fact that it have weak mechanical properties and also very high water

absorbance level which contributes mechanical failure under moist conditions.

xiv

PENGHASILAN DAN PENCIRIAN PLASTIK DARIPADA PLASTIC

ALGA MARIN

ABSTRAK

Dua objektif utama kajian ini adalah untuk menguji kebolehan menggunakan

alga marin sebagai bio-pengisi yang berkemampuan tinggi untuk penghasilan plastik

di mana plastic and dihasilkan akan mempunyai kecenderungan untuk mengurangkan

penggunaan sumber tidak boleh diperbaharui seperti petroleum yang menyumbang

kepada masalah ekologi yg membimbangkan. Satu lagi objektif adalah untuk

mencirikan campuran plastik dihasilkan menggunakan alga marin melalui ujian

fizikal, mekanikal dan degredasi haba. Dalam kajian ini, alga Marin dan polietilena

berketumpatan rendah digunakan sebagai bahan mentah dan dicampur untuk

menghasilkan sampel plastik yang kemudian dicirikan menggunakan kalorimetri

pengimbas pembezaan (DSC), Analyzer termogravimetri (TGA), dan penguji

tegangan serta ujian penyerapan air. Keputusan menyimpulkan bahawa alga marin

merah tidak sesuai untuk pengeluaran plastik tanpa sebarang pengubahsuaian

struktur molekulnya. Ini adalah disebabkan oleh ia mempunyai sifat-sifat mekanikal

yang lemah dan juga tahap penyerapan air yang sangat tinggi yang menyumbang

kepada kegagalan mekanikal di bawah situasi yang berkelembapan tinggi.

1

CHAPTER 1

Introduction

1.1 Background of study

A brief history of plastics predates back to middle ages. During these times,

plastics were mostly naturally occurring polymeric compounds which were used to

derive product of daily use. One of the examples would be the usage of animal horns

in building window frames and lantern heads. As time progressed, substitute

polymeric materials were made from lye treated milk protein-solids (casein). It was a

breakthrough when Charles Goodyear's discovery of vulcanization as a route to create

sulphur chains in materials derived from natural rubber was commercialized. Thus

from then till today the polymeric industry have underwent continuous revolution in

search of alternative and more suitable materials for various purposes.

In this research, the compounding of plastic blends with structurally

modified marine algae culture is to be studied as a new and profound way to progress

towards an environmental friendly production of plastics. Thus, we will discuss the

2

two major elements which is the core of this research, first being the study of the

algae and next the blending of plastics itself.

1.1.1 Marine Algae

Marine algae, more commonly known as seaweeds, come in various shapes

and sizes. Algae are not plants, even though they sometimes look like them. Algae

are relatively undifferentiated organisms which, unlike plants, have no true roots,

leaves, flowers or seeds. Algae do not have water-conducting tissues, as they are, at

some stage, surrounded by water, which is also important for reproduction by spores.

The spores may be motile or non-motile. Most of the algae are photosynthetic

organisms that have chlorophyll. Apart from chlorophyll, they contain additional

pigments, which are the basis of classification. Most of the seaweeds are red (6000

species) and the rest known are brown (2000 species) or green (1200 species).

Seaweeds are used in many maritime countries as a source of food, for

industrial applications and as a fertilizer. Nori, a type of Japanese red seaweed has a

high protein content (25-35% of dry weight), vitamins (e.g. vitamin C) and mineral

salts, especially iodine. Industrial utilization is at present largely confined to

extraction for phycocolloid, industrial gums classified as agars, carrageenan and

alginates. Agars, extracted from red seaweeds such as Gracilaria , are used in the

food industry and in laboratory media culture. Carrageenan, extracted from red

seaweeds are used to provide particular gel qualities. Alginates are derivatives of

alginic acid extracted from large brown algae, are commonly used as They are used

3

in printers' inks, paints, cosmetics, insecticides, and pharmaceutical

preparations. Alginates are used as stabilizers in ice cream.

In recent studies, there are an increasing number of researchers done which

are looking to get plastics from the sea by using marine life forms as a raw material

to make polymers. Algae are the most promising area of research right now. It is

already widely used as a raw material for biofuels, but this is increasingly extending

to plastics. The theory behind biopolymers is that they use sustainable resources,

rather than petrochemicals. The usage of naturally occurring sulphated

polysaccharide and phenolic polysaccharide which can be derived from these marine

algae is largely used as blending material for bio plastics. According to Frederic

Scheer, CEO, Cereplast one of the bio-plastic producing company, resin is to be

extracted from this crop to produce bio-adhesives which can be used to make

polymeric compounds. It is similar of how starch from corns and other

commercialized crops were used in obtaining polymers which will acts various

additives and matrix components in plastic production.

Figure 1.1: Chemical structure of the repeating dimeric units of λ-carrageenan

4

Figure 1.2: Chemical structure of the repeating dimeric units of fucoidal

1.1.2 Plastic and Plastic Blending

Plastic materials are range of products which are blended from synthetic or

semi synthetic organic solids that are moldable. Plastics have high average molecular

weight compared to other types of polymers and also contain other substance. These

plastics are most commonly synthesized from petrochemicals and are often are derived

with various characteristics and functions. The vast majority of these polymers are

based on chains of carbon atoms alone or with oxygen, sulphur, or nitrogen. Plastics

consists of carbon repeating unit which is linked together to form a polymeric chain

which is also known as the back bone. To customize the properties of a plastic,

different molecular groups attached to the backbone, as the side chains influences the

properties of the side chains.

Compounding consists of preparing plastic formulations by mixing and

blending polymers and additives in a molten state. There are different critical criteria to

achieve a homogenous blend of the different raw material. There are multiple additives

that is being used in plastic blending and formulation.

5

Fillers are mainly particles which are added to plastic compounding in order to

lower the consumption of more expensive binder material or to better some properties

of the mixture material. Formerly, fillers were used predominantly to cheapen end

products, in which case they are called extenders.

Coupling agents or better a polymeric coupling agent is a polymer that attaches

inorganic filler to the polymer matrix. Coupling agents have to be added in order to

reduce the repellence of the polymers and fillers respectively. This is because fillers are

largely added to polymer matrix in order to reduce the cost and so on.

Plasticizers or dispersants are additives that increase the plasticity or fluidity of

a material. The most commonly used plasticizer is phthalate ester. It is used to upgrade

or improve the flexibility and durability of plastic materials.

Flame retardant is chemicals used in thermoplastics, thermosets, textiles and

coatings that inhibit or resist the spread of fire. There additives are often added to make

the product more resistive towards thermal decomposition with different mechanisms.

Colorant is another additive which is used to give the produced plastic material a

suited colour. There are 2 methods of colour addition, first is the pigment addition.

This mainly involves addition of metallic colour pigment to provide the colour and the

next method is to use azonium dye.

6

1.2 Problem Statement

As there is an increasing awareness on environmental issues, the producing of

traditional petro-chemically derived plastics is not favorable. This is due to the fact

that synthetic plastics have high resistance towards environmental degradation

which takes up to thousands of years to decompose. The only way to dispose is

through land fill. Due to this, bio plastics are becoming a new replacement for

synthetic compounds as it is more prone to environmental attack and

decomposition.

Not only that, certain qualities can also be reinforcing i.e. mechanical strengths

via using natural additives or adhesives. In this study, the usage of marine algae as

a filler in polymer blending is tested to produce notable bio-plastic with elevated

properties and water resistance.

1.3 Objectives

There are two main objectives in this research of producing plastic from marine

algae. The first objective to investigate if marine algae are a viable source of bio filler

to produce plastic that is environmentally friendly whereby the plastic produced will be

biodegradable and slightly decomposed to smaller substances by living organisms from

marine algae.

7

The second objective is to characterize the algae plastic produced via TGA

(thermal gravimetric analysis), DSC (differential scanning calorimeter), FTIR (Fourier

Transformed Infrared Spectrometer), and water absorption testing.

1.4 Scope of study

The scope of this research includes the description and characterization of the

marine algae that will help in the plastic production process. Besides that the blending

of marine algae using different percentage of matrix and fillers (marine algae) is also to

be studied. The blended plastic is characterized according to the objective of the

research.

1.5 Significance of study

The result of this study will be a breakthrough in producing commercial grade

of bio-plastic as a substitution for existing synthetic plastic. Furthermore, the enhanced

properties and water resistive adaptation will be also promise a better material

production proposes.

8

1.6 Conclusion

As conclusion, the purpose of this study is to find out a new material which can be

synthesized to obtain a notable plastic blend to cope with the environmental problem.

This research will also benefit other researchers by providing information of

characteristics of marine algae plastic for further findings and modifications.

9

CHAPTER 2

Literature review

2. 1 Introduction

Formulating bio-based plastic blend is a relatively an unchartered scope of

study as it has not been commercialized yet. Despite this, there were many

researchers have been done where algae extract is used for multiple other factions.

In this chapter, commercialized study which has been done with marine algae will be

reviewed. Other than that, significant studies using Low Density Poly Ethylene

(LDPE) as a blending matrix will also be reviewed. In this research, LDPE is chosen

due to its usage in industry as a primary packaging material. It is the major source of

plastic which cannot be biologically degraded. Thus making it bio-degradable will

provide this research with a strong commercializing value. Also in this research, we

will review the process of structural modification which will be done to the towards

the algae extract. This step is under taken to modify the physical properties of the

polymer blend which will be created. Generally, it is presumed that bio-plastics have

10

a much lower mechanical properties compared to synthetic plastic, thus to overcome

this problem, this step is proposed.

2.2 Marine Algae

Seaweed can be classified into three bigger groups according to their

pigmentation or in laymen term colour which are brown, green, and red. In this

research we are using the red algae which have a vibrant colour due to the presence

of phycoerythrin. In most algae, the primary pigment is chlorophyll which is present

in most of the green plant. This algae also contains carotenoids, which are brown or

yellow,and phycobilins which are either red or blue. This accounts for the colourful

hues according to Khaled (1999). The red algae are multicellular which are

characterized by a great deal of branching presence in its molecular structure and

complex tissue where most of the algae belong to this group. The red algae are

commonly found in warm water regions and tropical climates and can grow in great

depts. compared to other species of algae. The red algae are a traditional part of

oriental cuisine.

The importance of marine algae as sources of functional ingredients has been

well recognized due to their diverse usage in multiple fields of studies. It is mainly

utilized in the pharmaceutical industry for is multi-vitamin possessing quality.

According to Ratih Pangestutia, Se-Kwon Kima,b,* on their paper on Biological

activities and health benefit effects from marine algae, the neutral pigment (NP) has

11

great deal of benefits. These NPs exhibit various beneficial biological activities such

as antioxidant, anticancer, anti-inflammatory, anti-obesity, anti-antigenic and

neuroprotective activities. This contribution focuses on biological activities of

marine algae-derived NPs and emphasizing their potential applications in foods as

well as pharmaceuticals areas. It was concluded that these NPs are an alternative

source for synthetic ingredients that can contribute to consumer’s well-being, by

being a part of new functional foods and pharmaceuticals.

In another research done by Ali A. El Gamal on biological importance of

marine algae, The microalgae phyla have been recognized to provide chemical and

pharmacological novelty and diversity. Hence, microalgae are considered as the

actual producers of some highly bioactive compounds found in marine resources.

The principal use of seaweeds as a source of human food and as a source of gums

(phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are

primarily constituents of brown and red algal cell walls and are widely used in

industry. Such property of algae exhibits an adhesive character due to the present of

lignin which can be utilised as a polymeric additive.

Figure 2.1: A few molecular structure of marine algae extract

12

This proves significance to our research that since its considered a

pharmaceutical product, it is vitally human friendly in addition to environmentally

green material. Obtaining the saccharine which also acts as an adhesive for our

polymer blend is justified as we can draw parallel and state that the material will

undergo environmental degradation. Thus it is a valid source for bio-plastic

production alternative.

Other than pharmaceutical usage, marine algae is also used to conduct

chemical bio-sorption.This is a process where heavy metal ions such as cobalt and

copper ions are bio-sorped onto the marine algae. According to K. Vijayaraghavan a,

J. Jegan b, K. Palanivelu c, M. Velan a,* on their paper on Biosorption of copper,

cobalt and nickel by marine green alga Ulva reticulata in a packed column, it is

stated that marine algae offer advantages for biosorption because their macroscopic

structures offer a convenient basis for the production of biosorbent particles suitable

for sorption process applications. This is due to the fact that this saccharide contains

sulphonic compound to their molecular chain. This compound acts as a good

adsorption platform for various metal ions. It is also stated that the presence of

phenol group in the chain aid the biosorption process as it aids localised attachment

of outer substances conjuring metal ions. As for the result of the study, green algae

exhibited very high copper, cobalt and nickel biosorption capacities in packed

column compared to most of the biosorbents. This alga showed unique ability to

remove all three heavy metal ions and retain its uptake capacity in three regeneration

cycles. In context of this research, we can conclude that this quality can ease the

structural modification as the bonding platform is already present in the algae

regarding reagent which involves metallic catalysts and so on

13

Algae are also widely considered an alternative source for bio-fuel

generation. On a study done by Gholamhassan Najafia, Barat Ghobadiana, Talal F.

Yusafb titled Algae as a sustainable energy source for biofuel production in Iran,

they stated that Algae can be converted directly into energy, such as biodiesel,

bioethanol and biomethanol and therefore can be a source of renewable energy. This

is due to fact that like other commercialized crop, it is a plat with natural fibre or

contains vast amount of polysaccharide which can be easily converted to the above

stated products. Because of its higher yield non-edible oil production and its fast

growth that does not compete for land with food production. Thus it is nothing but a

naturally occurring biomass in the since that the cultivation time is bare minimum

compared to commercialized crops. This is significant to our study as primary algae

oil extracted can be used to create plastic blending. With this abundant amount of

algae with no specific use, it can be commercialized via the waste to wealth concept

where the algae itself does not cost much investment.

.

According to Frederic Scheer, CEO, Cereplast one of the bio-plastic

producing company, resin is to be extracted from this crop to produce bio-adhesives

which can be used to make polymeric compounds. It is similar of how starch from

corns and other commercialized crops were used in obtaining polymers which will

acts various additives and matrix components in plastic production.

The red algae are chosen as the research raw material due to the fact that it

contains high amount of amino proteins primarily. This chains acts as the building

block for the protein formation which is a natural polymer. Besides that algae also

14

have good bond strength due to the presence of sulphite bonds in its microstructure

which aids the plant to grow in turbulent deep waters. Rhodophyta (red algae) have

this natural proteins and cellulose structure compared to other species according to

Nirmal et et (2010). This makes it a suitable bio-filler which is to be used in plastic

blending. There are many types of protein present in red algae. Researches are

conducted utilizing these chains in order to achive dimensional stability of the plastic

produced from red algae. The table below represents the types of amino acid

concentration and nitrogen content in Eucheuma cottonii as reported by Patricia

Matanjun (2007).

Table 2.1: Proteins in algae

Amino Acid (mg g-1 dry Weight)

Aspartic Acid (Asp)

2.65 ± 0.15

Glutamic Acid (Glu)

5.15 ± 0.13

Serine (Ser)

2.27 ± 0.04

Glycine (Gly)

2.27 ± 0.32

Histidine (His)

0.25 ± 0.10

Arginine (Arg)

2.60 ± 0.14

Threonine (Thr)

2.09 ± 0.01

Alanine (Ala)

3.14 ± 0.11

Proline (Pro)

2.02 ± 0.09

Tyrosine (Tyr)

1.01 ± 0.12

Valine (Val)

2.61 ± 0.07

Methionine (Met)

0.83 ± 0.17

Isoluesine (Ile)

15

2.41 ± 0.04

Luesine (Lue)

3.37 ± 0.06

Phenylalanine (Phe)

19.07 ± 2.48

Lysine (Lys)

1.45 ± 0.48

Chemical Score (%)

25.6

Most limiting amino

acid

lysine

Total amount

52.86 ± 3.37

2.3 Low density poly-ethylene (LDPE)

The main reason LDPE is the primary choice in this research is because of its

common usage in general industries and domestics. It is widely used as a packaging

material such as high quality plastic wrappers and other plastic materials such as

plastic disposable drinking bottles and other forms of thermoplastics. As per

statistics, almost 75% of this material does not undergo biological degradation since

its manufactured from synthetic polymer mainly from petroleum. Thus targeting this

market gives an imperative value of marketing and a big step towards environmental

preservation. Both usage of natural recourses and environmental problem can be

reduced dramatically.

In a research done by Worawan Pechurai, Charoen Nakason _, Kannika

Sahakaro on Thermoplastic natural rubber based on oil extended NR and LDPE

Blends; LDPE was tested and used as a matrix for the blending. It was stated that

blending of polymers has been widely investigated as a simple and practical means to

16

obtain new materials with novel properties. In this case NR and LDPE blends were

considered as it produced interesting TPE materials. This type of blend is favourable

because it which the excellent processing characteristics of LDPE which eases the

production of thermoplastic elastomers with a upgraded quality compared to LDPE

or PP. Another reason is due to its attribute of large melt viscosity and molecular

weight of HDPE. This leads to inferior performance in mechanical properties. As a

result, that Influence of PhHRJ-PE on rheological and tensile properties of a simple

blend of 60/40 OENR/HDPE was first studied. It was found that at a given shear rate,

the apparent shear stress and shear viscosity of the blend was higher compared to that

of PP or LDPE. Also it was found that modulus and elongation at break of the blend

with the PhHRJ-PE were higher in the experiment. This proves that mixing LDPE as

the matrix is very much more favourable due to its processabilty and better

mechanical property.

In another research on Nanoclay reinforced LDPE as a matrix for wood-

plastic composites by Omar Faruk, Laurent M. Matuana, LDPE was used as a

preferred medium to enter nanoclay into the wood composite. LDPE was a preferred

as to investigate the main

goal of this study which was to examine whether or not the addition of nanoclay

could also enhance the bending properties of LDPE matrix -based WPCs. Particular

emphasis was placed on examining the effect of nanoclay types and as well as its

addition sequence on the properties of the composites. Thus we can conclude that

LDPE was used as matrix in this study to utilize its flexible characteristics and to test

if it can induce a bending effect upon the produced composite. Enhancing the

bending properties of WPCs using LDPE matrix could expand their acceptance in

17

load bearing structural applications. Again, mechanical properties of this matrix were

another factor. As conclusion, the result indicated that the flexural properties of

LDPE/wood-flour composites could be significantly improved with an appropriate

combination of the coupling agent content and nanoclay type in the composites

compared to study finding which was done using PVC as a matrix. The flexural

strength of composites made with nanoclay reinforced LDPE matrix compared

favourably with that of various species of solid wood.

On the paper A mechanical analysis on recycled PET/LDPE composites by

Antonio F Ávila, Marcos V Duarte

b. The large amount of disposable bottles

presently produced makes imperative the search for alternative procedures for

recycling or reuse of these materials, since they are not biodegradable. Thus the

LDPE/ PET is chose due to its overwhelming usage in industry. The study suggests

that the recycling of the plastic blends have potential for use not only in engineering

applications but also in our daily life where their ultimate strength ranging from 22 to

28 MPa is a clear evidence of their capability. It was also emphasize that, the

addition of LDPE particulates into a PET solution reduces the effective stiffness of

the blend but LDPE phase gives a major contribution to milling operations, as it

decreases the surface roughness by allowing a higher cohesive condition between

PET and LDPE. Despite this feature, it was also clear that continuous recycling of

the product will only yield in a lower graded plastic thus the final stage of

incineration or landfill is inevitably unavoidable. Thus in this research, we will blend

LDPE with the modified algae extract to produce a bio-plastic which will degrade

with time.

18

In a nut shell, other than the fact that LDPE is the major product used in

packing material production, it is also largely used in researches for its optimal

processing characteristics. It is also said to have better mechanical properties

compared other various polymers when it comes to blending.

2.4 Structural Modification

Modification of structure of a particular polymer is carried out to enhance the

positive attributes and eliminate the shortcomings of the native polymer. For

example, in this part we will review how starches were modified structurally to

confine them for different purposes in industry. Modification of structures an ever

evolving industry with numerous possibilities to generate novel modified compounds

which includes new functional and value added properties as a result of modification.

This is connected to the main research as the algae extract which we have must be

structurally modified as to analyse its mechanical properties in comparison with the

one’s without. Moreover it is believed that modified compound have much preferred

properties in terms of industrial applications.

Referring to a journal on Progress in starch modification in the last decade of

food biopolymer journal by Bhupinder Kaur, Fazilah Ariffin, Rajeev Bhat, Alias A.

Karim, it was stated that starch modification includes three broad areas that are

chemical, physical, and enzymatic modification. Chemical modification of starch

involves the polymer molecules of the starch granule in its native form. Modification

is generally achieved through derivatization such as etherification, esterification and

19

crosslinking, oxidation, cationization and grafting of starch. Physical modification

can be safely used as a modification process in food products as it does not

chemically alters or reforms the essential nutriendts in the product. Next is enzymatic

modification which mainly used hydrolyzing enzymes in its modification. One of its

products is syrup be it glucose syrup or high fructose corn syrup. These enzyme are

generally derived from bacteria and fungi.One such example is high-amylose potato

and pea starch with amylomaltase (AM) modified with the hyperthermophilic

bacterium Thermus thermophilus.

Figure 2.2: enzymatic modification of amylase and amylopectine with amylomaltase

According to A.L. Chaudhary a,*, M. Miler b, P.J. Torley a, P.A. Sopade a,

P.J. Halley on their paper on Amylose content and chemical modification effects on

the extrusion of thermoplastic starch from maize, the characterized how hydroxy

proplylated maize starch thermo plastic ,mechanical processing is more efficient

compared to unmodified maize starch thermoplastic. The design of experiments

showed that starch type for both unmodified and modified maize had a statistically

significant effect on parameters such as torque, die pressure and specific mechanical

energy and that screw speed also significantly affected specific mechanical energy.

With that it was concluded that modifying the hydroxyl-proply group possess a better

process ability. The result of the experiment showed that hydroxypropyl modified

20

starch affects its gelatinisation behaviour by increasing interactions with water

molecules which in turn can result in a lower viscosity. This was evident with a

reduction in torque, die pressure when compared to the unmodified 80% amylose

starch. This proves that such modification will actually rake in more profit as it

reduces power consumption due to easier processability. In terms producing

environmentally green plastic, blends done from maize starch is biodegradable as

well as runs under a low power consumed operation due to the modified property.

In another research done on Thermoplastic starch modification during melt

processing: Hydrolysis catalyzed by carboxylic acids by Antonio J.F. Carvalho a,*,

Marcia D. Zambon b, A. Aprigio da Silva Curvelo b, Alessandro Gandini b,

modification to the starch was done by forming ether links between chains in order to

have a better mechanical characteristics to the polymer blend. This was achieved via

processing glycerol-plasticized starch in the presence of non-volatile carboxylic acids

which induces a acid catalytic hydrolysis and fabricated ether cross linking between

the polysaccharide chains. As a result, the decrease of the molar mass of starch

polysaccharides over a wide range of values by the use of small amounts of

carboxylic acids, as additives during melt processing, results in a promising way of

preparing biodegradable thermoplastic materials with controlled properties. One

such property was a more resistance towards water absorption we it was proved the

modified starch uptake less water compared to unmodified starch. As conclusion, the

use of non-volatile and non-toxic acids as catalysts, provides the additional

advantages of health safety and food compatibility in, e.g. packaging applications for

these materials

21

2.5 Polymer blending

The mixing of the matrix and the filler adhesive is one of the most crucial

steps in the polymer production line. Ensuring proper blending is required to produce

a uniform material in the sense of chemical composition. There are 2 main blending

methods that is currently practised in the industry. First is reactive blending where

chemically active reaction such as polymerization will occur during the blending

process which would be done via extruder. The other methods are melting blending

where there aren’t any chemical or structural modifications occurring in the

microscopic scale. In this process, the blend is created by producing a homogenous

liquid of the plastic, fillers and other additives where complete mixing is ensured. In

this research, melt blending is used where modified or unmodified marine algae is

mixed with LDPE and extruded out.

According to Rachele Pucciariello*, Vincenzo Villani, Carlo Bonini, Maurizio

D’Auria, Teresa Vetere of the journal Physical properties of straw lignin-based

polymer blends stated that melt blending is essentially a conventional polymer

production method. In their study Lignin powder was used in preparation of blends

with low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE),

high-density polyethylene (HDPE) and atactic polystyrene (PS) to produce bio-

thermoplastic. The composition of lignin and the matrix was varied. The blending

was done via an extruder where both the ingredients in respective studied ratio were

fed into the feed hopper, the blending commenced where both compounds were

melted and blended together. The result of the study states that the modulus slightly

22

increases for most lignin-polymer blends, while the tensile stress and elongation

reduce. Moreover, lignin acts as a stabilizer against the UV radiation for PS, LDPE

and LLDPE.

Polymerization blending for compatible poly (ether sulfone)/ aramid blends based on

polycondensation was done by Hideo Hayashi where Poly(oxy-1,4-

phenylenesulfonyl-1,Cphenylene) and (PES) and poly (m-phenyleneisophthalamide)

were blended readily via reactive blending. The polymerization process takes place

during the blending process. The findings proved that the tensile modulus and tensile

strength of the blend films were improved over the entire PESj/PMIA composition

range by using the polymerization blending method. The polymerization-blended

films had a high elongation at break over a relatively wide composition range

compared to conventional solution blending method.

2.6 Polymer Characterization

FTIR spectroscopy has been previously acknowledged as one of the most

widely used techniques in the polymer industry for its characterization of polymers.

Recently, FTIR has also been applied to evaluate the radiative thermal properties of

several types of foams. According to Glicksman, the changes of the infrared intensity

through polyurethane foams can be measured with FTIR to even determine thermal

properties of polymer compounds. The main function of FTIR is to analyse the

composition of a substance. The working theory is simple where the tested

compound is exposed to infrared rays and the chemical bonds between the molecular

23

structures of the compound will absorb different amount of ray and this is

represented as the wavelength of absorbance. Using this wave length and the

intensity of absorption, the functional group which is present in the compound can be

determined. The analysis for protective polymer coating is as below. Transmittance

represents the intensity of the compound and the wave number is the wavelength

absorbed by the molecular bonds. (cited from the journal “Measurement of radiative

and chemical composition of polymer flims using FTIR” by Huijun Wu, Jintu Fan,

2007)

Figure 2.3: FTIR analysis Peaks

Differential screening calorimeter (DSC) and Thermogravimetry Analysis

(TGA) is another common polymer characterization method. DSC is used to reveal

the effects of different blending ratios on their melting and crystallinity behaviour

and thermogravimetry (TGA) to reveal the degradation characteristics of the blends

in terms of their induction time. According to A.C. Wong and Lam on their journal

titled “Study of selected thermal characteristics of polypropylene/polyethylene

binary blends using DSC and TGA” the blending of different polymer will have

effects on the thermal properties of the mixture i.e. difference in melting point

24

temperature, crystalline temperature and thermal degradation properties. This can be

analysed easily using DSC and TGA. A thermo-gram with peaks representing the

melting point properties and crystalline properties will be generated by DSC

analysis.

Figure 2.4: DSC analysis peaks

From the figure, the Tm represents final melting temperature and the Tcp

represents the crystalline temperature. Using this test we can compare how the

melting point varies with different compositions of blending.

The weight loss of a polymer as a function of time or temperature is

commonly determined by the technique of TGA. Weight loss of a polymer due to

thermal degradation is an irreversible process. This thermal degradation is largely

related to oxidation whereby the molecular bonds of a polymer are attacked by

oxygen molecules. The data will be represented as the figure below. The part a) in

the figure represents percentage of weight loss of the compound at different

temperatures and the peak represents the temperature where a specific compound is

oxidised.

25

Figure 2.5: TGA Analysis diagram

Water absorption test is another common test conducted on polymers to observe their

water absorption properties. As a rule of thumb, it is desired in plastic industry that

plastic manufactured exhibits a low water absorption property. This is. According to

Han-Seung Yang’s journal “Water absorption behaviour and mechanical properties

of lignocellulosic filler–polyolefin bio-composites” having a bio-filler increases the

the tensile strength of the composite produced but under the presence of moisture,

the tensile strength reduces significantly. The water absorption test is conducted by

immersing the composite in water for 24 hours and by calculating the water intake

and later tested for tensile testing.

2.7 Conclusion

As a conclusion, multiple articles have been reviewed and discussed ranging

from the researches that have been conducted with marine algae, LDPE as a matrix,

possible ways of structural modification and also ways of blending. Hence further

26

research on these explained fields will produce conclusive evidence on the method

selection to run the research on producing bio-plastic via marine algae. As from the

literature review melt blending is decided to be the effective option to produce the

LDPE and marine algae plastic blending. It is believed that this research will be able

to further induce other researches on utilizing marine algae as a source of efficient

adhesive material with elevated mechanical property.

27

CHAPTER 3

Methodology and Materials

3.1 Introduction

This experiment is conducted by experiment where red algae are used as bio-

filler to produce plastic blend with LDPE. This particular species of algae is

harvested and shipped from Semporna, Sabah. The main aim is to produce a good

plastic sample using thermo plastic as well as thermo mechanical processing to

produce the plastic. In this way off processing the treated marine algae is blended

with Low Density Poly Ethylene is blended using twin screw for superior blending to

obtain highly homogenised plastic-algae composite in a wire like form. Apart from

that, hot press is used to mould the produced sample into dog bone shape for further

testing i.e. tensile testing and water absorption testing. These methods are simple

and effective in plastic formulation in lab scale and testing purposes.

28

3.2 Processing Flowchart

Pre-Treatment of marine algae

Algae is vigorously washed with continuous stream of warm water

Algae dried at 60 for 48 hours

Algae is the grinded using cutter mill, sieved and stored

The treated algae and LDPE pallets are weighed according to the

blending ratio

Blending Process is done in twin screw extruder at 130 and 50 rpm screw speed

Extruded plastic is the palletized using the standard palletiser

29

Palletised sample is the moulded into dog bone shape using hot press

Samples are sent for testing and step 5 to 9 is repeated for all the different

blending ratios set

3.3 Materials

1. Red Marine Algae

2. Low Density Poly Ethylene

3.4 Equipment

1. Twin Screw Extruder

2. Hot Press

3. Fourier Transform Infrared Spectroscopy (FTIR)

4. Differential Screening Calorimeter (DSC)

5. Thermo-gravimetric Analyzer (TGA)

6. Tensile Tester

30

3.4.1 Extruder

To fabricate the plastic in this research, a twin screw extruder branded thermo

Scientific was used. The extrusion process is done whereby the feed materials in this

case the palletized LDPE and treated marine algae is fed through the feed hopper

according to the ratio set where it is heated and homogenized by the twin screws

present inside the extrusion barrel. Twin screw extrusion is used mainly for its

superior homogenized mixing feature to help evenly distribute the algae bio-filler

evenly throughout the LDPE matrix which is being extruded. The extruder is fitted

with a standard palletizer where the extruded plastic is cut to standard palletized

form.

Figure 3.1: Thermo Scientific Extruder

3.4.2 Hot Press

Hot pressed is used to mould the produced plastic into dog bone shape for

tensile testing and water absorption test. This is done by pressing the sample under 1

atm pressure at 140 for 45 mins.

31

Figure 3.2: Hot Press

3.4.3 Fourier Transform Infrared Spectroscopy (FTIR)

FTIR is used to identify unknown materials, to determine quality or

consistency of a sample and ultimately identify the components in the tested

material. The FTIR works in a way where infrared rays are emitted onto the sample

and the sample will absorb a certain part of the ray. Using this, the component is

identified via the wave number it absorbs.

3.4.4 Differential Screening Calorimeter (DSC) and Thermo-gravimetric

Analyzer (TGA)

DSC and TGA are used to analyze the thermal properties of the plastic blend

produced. DSC will be used to determine the melting point and the crystallizing

temperature of the plastic sample. This is done using the heat-cool-heat method

32

where the sample will be heated to 120 and then cooled down to 40 . The data

obtained will be used to compare the varying trend of melting point and crystallizing

temperature with increasing composition of marine algae.

Figure 3.3 DSC Machine

TGA on the other hand is used to observe the thermal degradation of the

plastic sample with increasing temperature. The sample is heated up to 600 with a

ramping rate of 20 per min. the results obtained can be used to study what

components are degrading first with the present temperature.

33

Figure 3.4 TGA Analyser

3.4.5 Tensile Tester

Tensile tester is used to determine the strength of the plastic produced. After the dog

bone shaped sample is fabricated, tensile testing is done to to identify the strength of

the material produced. The Instron Tensile Tester with load of 50 KN is used. The

elongation at break in percentages is also measure and recorded

3.5 Method of Research

3.5.1 Sample Preparation and Procedures

200g of sample is to be produced for every blending ratio. Therefore the

composition of the compounds to be mixed is as follows:

34

Table 3.1: blending composition of samples in % and grams

LDPE % Algae % Mass of LDPE

(g)

Mass of Algae

(g)

100 0 200 0

95 5 190 10

90 10 180 20

85 15 170 30

80 20 160 40

The sample with the above composition is weighed stored. These samples are than

fed into the extruder to be blended. After a series of trial and error, it was found out

that the best processing parameter is at 130 and 50rpm screw speed. After the

samples are extruded, it is palletized using the standard palletizer to less than 5mm.

After that, the samples are molded into “dog bone” shape using the hot press. Since

the hot press parameters will significantly influence the tensile properties of the

samples made, optimization is done by producing samples at different temperature

and time and testing its tensile strength.

Using the optimum temperature and pressing, all the samples are moulded.

The samples are the analyzed with DSC, TGA, Tensile testing machine to find out

the physical and thermal characteristics. Water absorption test was also conducted to

analyze the water intake of the plastic sample made with increasing filler used. FTIR

tests were also conducted to identify the functional group present in the plastic

sample produced by thermo processing method.

35

CHAPTER 4

RESULTS AND DISCUSSION

4.1 Introduction

In this chapter all the characterization test results are compiled, reviewed and

discussed to deduce if red marine can be utilized as prominent bio filler in producing

plastic composite. The difference and similarities between all 4 algae samples with

5%, 10%, 15%, and 20% of algae and the pure LDPE sample will be analyzed.

During the extrusion of the plastic blends, the operating conditions of the twin screw

extruder were determined by trial and error. The samples were then palletized using

standard palletiser to a length of 5mm.

The palletized samples were then used to run DSC, TGA and FTIR. DSC and

TGA were used to study the thermal properties of all 5 plastic samples (pure, 5%,

10%, 15%, and 20%). The results were then comparing to find out the relationship

between how the algae filler composition influences the thermal properties. Also the

samples were studied using FTIR to identify any changes in the molecular structure

of the plastic/algae filler blending and the components present in it. Since different

36

bonds have different level of absorbance, it is common that each peak in the FTIR

analysis shows a part of the molecule present in the compound.

Tensile strength of the components was determined using the tensile testing

machine. All 5 samples were molded into dog bone shape using hot press the tensile

strength was determined by applying continuous force to the specimen until it breaks

or rupture. Besides that the percentage of elongation at break can also be determined

by observing the maximum displacement before rapture from the tensile test data.

Apart from all these tests, water absorption test was also conducted to observe the

how the water uptake varies with increasing algae filler in the composition.

Theoretically, it is said that plastic blending with high water absorption properties are

not suitable for moist condition as these material will show mechanical failure under

wet conditions. Hence with that, a conclusion of whether red algae are suitable filler

will be drawn.

37

Figure 4.1: Plastic Blend 5%, 10%, 15%, and 20% for top left to bottom right

4.2 Extrusion Process

Optimization of twin screw extruder parameters were obtained by trial and

error as mentioned above .The conditions of temperature were manipulated between

120 and 150 and finally the temperature of 130 was used as the sample fed

into the extruder was easy to handle as it was extruded. The optimal points were

decided based on physical observation of the extruded plastics appearance. It was

found that at temperature of more than 130 , the algae filler start to disintegrate and

burn. This situation is to be avoided as burned filler will influence the physical and

mechanical properties of the plastic blend produced. The screw speed is also set to

ease the process ability of the plastic blend and it was found the screw speed of

50rpm is the optimal screw speed to be used.

38

4.3 Hot Press: Parameter Optimization

Initially, the usage of injection moulding was to be used to make the dog

bone shaped sample, but due to unavailability of the instrument, the experiment was

improvised and hot press and mould was used instead to produce the tensile testing

samples. Though there are 2 major draw backs of using this method, firstly the

formation of air bubbles in the sample and secondly the sample made can be non-

homogenised. To solve this problem optimization of time and processing temperature

is done. The optimization process was done by preparing 4 samples for of 1 plastic

sample produce at different temperatures and another 4 samples at different pressing

time. Then all the samples were tested for its tensile strength. The results of the data

is as follows:

Table 4.1: Hot Press Temperature optimization

Sample

No Temperature Tensile Strength

(N/mm)

Time (min)

1 120 5.8512 30

2 130 6.0501 30

3 140 6.6204 30

4 150 6.2042 30

39

Figure 4.2: Graph of Tensile strength vs. Temperature

Table 4.2: Hot Press Time Optimization

Sample

No Temperature Tensile Strength

(N/mm)

Time (min)

1 140 5.2238 15

2 140 6.6204 30

3 140 6.463 45

4 140 6.0194 60

Figure 4.3: Graph of Tensile Strength vs. Time

y = 0.0149x + 5.5243 R² = 0.2114

5

5.2

5.4

5.6

5.8

6

6.2

6.4

6.6

6.8

0 10 20 30 40 50 60 70

Ten

sile

Str

en

gth

/ (N

/mm

)

Time/ min

Graph of Tensile Strenght vs Time

5.8

5.9

6

6.1

6.2

6.3

6.4

6.5

6.6

6.7

100 110 120 130 140 150 160

Ten

sile

Str

en

gth

/ (N

/mm

)

Temperature/ ̊C

Graph of Tensile strength vs Temperature

40

From the representation of optimization data above, the optimized

temperature can be concluded is at 140 from the first graph and the time

optimization is approximately 35 minutes. These conditions were applied to obtain

the best results for strength of the plastic sample moulded. Assuring well-controlled

processing parameters ensures less air bubbles formation and also better heat

conduction for even melting and moulding of the plastic/ algae sample without

burning the algae filler hence not decreasing the mechanical property. The moulded

plastic is then cooled and stored to do maximum tensile testing.

Figure 4.4: Mould (top), Dog bone testing sample (bottom)

41

4.4 Differential Screening Calorimeter (DSC) and Thermo gravimetric Analyser

(TGA)

In characterize the plastic blending produced, thermal properties of the

plastics were analysed using DSC. The samples (Pure, 5%, 10%, 15%, and 20%)

were analysed to obtain their melting point temperature and crystalizing temperature.

The result of the analysis for the pure sample is as follows bellow and all the other

curves is to be attached at the appendix.

Figure 4.5: DSC Profile for 5% of algae

42

In this diagram, the upper peak represents the crystalizing temperature or

glass transition temperature of the sample. The lower peak represents melting point

of the pure LDPE sample produced.

Table 4.3: Glass Transition Temperature and Melting Temperature for DSC test

Sample No Composition of

Algae (%)

Glass Transition

Temperature Tg

( )

Melting

Temperature

( )

1 0 96.74 107.08

2 5 96.89 105.67

3 10 97.09 106.24

4 15 96.87 106.36

5 20 97.11 106.42

Figure 4.6: Graph of Melting Point vs. Algae Composition

y = -0.0106x + 106.47 R² = 0.0275

105.4 105.6 105.8

106 106.2 106.4 106.6 106.8

107 107.2

0 5 10 15 20 25

Me

ltin

g P

oin

t/

Algae composition/ (%)

Graph of Melting Point vs Algae Composition

43

Figure 4.7: Graph of Glass Transition Temperature vs. Algae Composition

Referring to figure above we can see that the melting point of the samples

increase with increasing composition %. Though, the melting point of pure LDPE is

somewhat higher compared to all the other samples. This is probably due to the fact

that since there are no impurities in the pure sample, it’s likely that the bonds

between the polyethylene molecules are retained. Introducing algae filler interfere

with this bonding or creates an alternate bond with the polyethylene and breaks the

polymeric structure of the overall molecular. The boiling point increases as more

algae in introduced and more of these alternative bonds are created in its

microstructure. The glass transition temperature however shows an overall

increasing trend. The fluctuation of the Tg temperature can be due to some

experimental error hence the fluctuated point can be assumed to be false. Taking that

into consideration, the trend of Tg increases steadily with increasing composition

percentage of algae.

y = 0.0144x + 96.796 R² = 0.5247

96.7

96.8

96.9

97

97.1

97.2

0 5 10 15 20 25

Tg /

(

)

Composition (%)

Graph of Glass Transition Temperature vs Composition

44

Figure 4.8: TGA profile for 5% algae composition

TGA analysis on the other hand can be analyzed to study how the sample

degrades with ramping temperature of 20 / min up to 600 . From the result, we

can observe that the degradation occurs at the 425-500 . We can conclude that the

polymeric compound which is LDPE degrades at this range as the reduction in mass

high decreases at the same temperature region. All the other composition exhibits the

same trend accepts for algae with 20% composition.

45

Since the amount of algae in the 20% composite is becoming more significant, it is

safe to say that the algae start to decompose first. This is because from the TGA

analysis of 20% composition shows a slight decrease at the temperature region of

175 to 250 . Hence it is safe to say that the algae decomposition temperature is at

about 180 .

Figure 4.9: TGA profile for 20% algae composition

4.5 Tensile Testing

Tensile test is done for all the samples using a ramping force method. The

force is set at 10mm per min. Having done the test for all 5 samples which were

produced under the optimized hot press parameters of 140 and 35min of pressing

time, it was found out the material with composition of 10% had the best tensile

strength among all the other composition but not surpassing the tensile strength of

46

the pure sample. The sample with 10% algae filler had tensile strength around 6.60

N/mm while the pure samples with no algae composition gives a tensile strength of

9.28 N/mm The testing data obtained is represented in the table below:

Table 4.4: Tensile Strength and Elongation at Break profile for varying algae

composition

Sample No Composition

(%)

Maximum

Tensile

strength

(N/mm)

Max

Displacement

(mm)

Initial

length

(cm)

Percentage

of

Elongation

(%)

1 0 9.2811 37.384 1160 0.0322

2 5 6.6075 15.848 1070 0.0159

3 10 6.6204 20.918 1320 0.0151

4 15 6.0592 11.376 1090 0.0104

5 20 4.1805 5.0027 1030 0.0040

Figure 4.10: Graph of Tensile Strength vs. algae composition

y = -0.215x + 8.6996 R² = 0.8673

0

2

4

6

8

10

0 5 10 15 20 25

Ten

sile

Str

en

gth

/ (N

/mm

)

Composition /(%)

Graph of Tensile Strength vs Composition

47

The tensile strength of the LDPE and algae blend exhibits lower mechanical

properties than the pure LDPE sample. This is probably because the algae’s

molecular structure did not bind or form bonds with the polyethylene structure

causing it to be an isolated particle. These in terms serves as a point of rupture thus

the bonding surrounding the algae grains are weak. Thus the plastic blended using

algae as filler is weaker than that of the pure LDPE itself. But among the

compositions with algae, the composition with 10% of algae shows best tensile

strength. This is possibly due to the fact that 10% of algae composition is well

homogenised as and better molecular bonds are established among the intermolecular

structure of the polymer itself. As for the % of elongation, the trend below show that

it decreases as the algae composition increases. This is because more algae filler

makes the plastic made more brittle.

Figure 4.11: Graph of Elongation vs. Algae Composition

y = -0.0012x + 0.0279 R² = 0.8759

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0 5 10 15 20 25

Elo

nga

tio

n (

%)

Composition (%)

Graph of Elongation vs composition

48

4.6 Water Absorption Testing

Water absorption test are done by soaking the moulded sample into water for

duration of 24 hours. The amour of water absorbed is calculated in percentage to give

a clearer picture. From the results obtained, we can conclude that increasing the

composition of the algae increases the water absorbing ability of the plastic blended

greatly, hence it has a poor water resistance property. The figure below shows the

trend of water absorption with varying algae composition.

Table 4.5: Water absorption profile with varying algae composition

Figure 4.12: Graph of Water Absorbance vs. Composition

Sample Composition (%) Initial Weight

(g)

Final weight

(g)

Water

absorbance

(%)

1 0 5.0139 5.1188 21

2 5 6.8466 8.3109 22.3

3 10 6.9561 10.820 55.5

4 15 7.1779 18.5103 157.87

5 20 7.4023 22.638 205.81

y = 10.104x - 8.542 R² = 0.8948

-50

0

50

100

150

200

250

0 5 10 15 20 25

Wat

er

Ab

sorb

ance

(%

)

Composition (%)

Graph of Water Absorbance vs Composition

49

Hence we can conclude that using algae filler is not suitable for situation

which involves high moisture thus limiting its application. Algae after absorbing the

water will swell up and become mushy, thus it will decrease the mechanical

properties of the blended plastic.

4.7 Conclusion

As a conclusion, after reviewing all the characterization of the algae and

plastic blend produced from marine algae, we can conclude that it does not show a

very promising potential as compatible filler with LDPE matrix. But the tensile

strength obtained is fair as this material can be used for other purposes which does

not involve high amount of force being applied to it.

50

CHAPTER 5

Conclusion and Recommendations

The characterization of the plastic blending produced that have been done via

mechanical, thermal and physical testing will be used to draw a conclusion and

answer our objectives of this research. In this research, we have discovered that the

optimum processing parameter for the plastic blending sample in dog bone shape is

at 140 and 35 min pressing time. The best composition was found to be 10% of

algae blend where it exhibits the best mechanical property and other characteristics

such as melting point, thermal degradation and other tests. However a lot of

modifications and alternative polymer processing techniques must be applied to be

able to commercialize plastic blends made out of marine algae. Hence without any

modification, the red marine algae are not a suitable material to be used for plastic

blending. The general trend shows with increasing composition of the algae, the

tensile strength decreases. The water absorption property on the other hand increases

drastically suggesting that plastic made from algae will have very weak performance

under are with high humidity. The glass transition temperature also increases with

increasing composition.

51

To improve the quality of the plastic blended using marine algae, the algae

must first be treated or hydrolyzed to obtain the polymer extract i.e. carrageenan

from the marine algae and use that as a blending resin instead of using it as a bio-

filler. This ways, the algae plastic can be homogenized easily and it will be more

compatible other polymer matrix. The Agar which can be extracted from the red

seaweed should also be studied as it possesses good bio-polymer properties. Journals

suggest that agar can help slow down brittle properties of plastic materials produced

while enhancing the effectiveness of binding agent. It also has a strong radio wave

radiation resistance. Apart from that, chemicals such as coupling agents and binders

can be used to test if it can help the bonding process of the molecular structure to

make them stronger. Binders such as ethyl glycol should be used during the extrusion

process to make sure superior blending. Injection molding should be used instead of

compression molding. This is because injection molding will ensure a better dog

bone sample without any air bubbles and uneven distribution of algae and matrix.

This will enhance the tensile property of the plastic produce. Biotechnology

techniques can play a very crucial role in making algae a viable source for plastic

fillers or bio-polymers. This is because algae can be genetically modified and grown

for specific purposes i.e. for polymer extraction.

52

Other researches can also be considered to be done with marine algae. Marine

algae have an enormous water absorbing ability. This makes it a very weak plastic

material in terms of conditions with moisture. Instead, this property should be

embraced and researches should be done to produce super absorbent from marine

algae’s instead. I believe algae will definitely excel in the prospect. Other than that,

the high protein ingredient contained by algae allows it to be researched to produce

cosmetic products such as cream with anti-aging properties, hair nourishment

shampoo and so on.

53

REFERENCES

Ali A. El Gamal, Biological importance of marine algae (2009)

A.J.F. Carvalho a, A.A.S. Curvelo a, A. Gandini a,b, Surface chemical modification

of thermoplastic starch: reactions with isocyanates, epoxy functions and stearoyl

chloride (2004)

Antonio J.F. Carvalho a,*, Marcia D. Zambon b, A. Aprigio da Silva Curvelo b,

Alessandro Gandini , Thermoplastic starch modification during melt processing:

Hydrolysis catalyzed by carboxylic acids (2005)

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54

Appendix A: Gantt Chart

Appendix B: Differential Screening Calorimetric Analysis

Appendix C: Thermo-Gravimetric Analysis

55

APPENDIX A

Undergraduate Research Project 1 Gantt Chart

Undergraduate Research Project 2 Gantt Chart

FEB MARCH APRIL MAY

Brainstorm

Deciding Title

Plan Work

Research Topic

Search

Literature

Chapter 1

Chapter 2

Chapter 3

Abstract

Presentation

Submission Of

Draft

Proposal

Submission

SEPT OCT NOV DEC

Material Order

Application for

Equipments

Plan Work

Run

Experiment

Search

Literature

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Abstract

Presentation

Submission Of

Draft

Report

Submission

56

APPENDIX B

DSC Analysis Results

5% algae composition DSC result

57

10% algae composition DSC result

58

15% algae composition DSC result

59

```

20% algae composition DSC result

60

APPENDIX C

TGA Analysis Results

TGA analysis for pure LDPE

61

TGA analysis for 5% algae composition

62

TGA analysis for 10% algae composition

63

TGA analysis for 20% algae composition