Fibre-Plastic Composites: Oil Palm Frond and Rubberwood Fibres Blended with Polypropylene

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UNIVERSITI PUTRA MALAYSIA

FIBRE-PLASTIC COMPOSITES:

OIL PALM FROND AND RUBBERWOOD FIBRES

BLENDED WITH POLYPROPYLENE

LIEW KANG CHIANG

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FmRE-PLASTIC COMPOSITES:

OIL PALM FROND AND RUBBERWOOD FmRES BLENDED�H POLYPROPYLENE

By

LIEW KANG CHIANG

Thesis submitted

in

fulfilment of the requirements for

the Degree of Master of Science

in

the Faculty of Forestry,

Universiti Putra Malaysia.

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ACKNOWLEDGEMENTS

The author wishes to express his sincere gratitude to his supervisory committee consisting of

Dr.

Jalaluddin

Harun

and Dr. Paridah Md Tahir (UPM), Dr.

Khairul

Zaman Hj. Mohd. Dahlan (MINT) and Dr. Mohd. Nor Mohd. Yusoff (FRIM) for their untiring and invaluable guidance, cons�ctive criticisms, comments and suggestions throughout the course of this study.

Special thanks are due to Universiti Putra Malaysia for sponsoring the author's study and also to the Dean of Faculty of Forestry, UPM, Assoc. Prof. Dr. Rusli Mohd., for his pennission to use the available facilities.

Words of thanks are also conveyed to Mr. Wan Ali Wan Yusof and Mrs.Chantara Thevy Ratnam of MINT, Mr. Yong Fook Onn, Mr. Saimin Basir and

Mr.

Mohd. Deraman of FRIM, Mr. Hoi

Oi

Kuan, Miss Azilah Ab. Jalil and

Puan Aminah

Jusoh of the Electron Microscope Unit, Faculty of Veterinary Medicine and Animal Science,

UPM,

and Mr.

Harmaen Ahmad Saffian, Mr. Zainal Abidin and Mr. Abd.

Razak

of Faculty of Forestry,

UPM,

for their assistance during the experimental work. Acknowledgement is also due

to those involved directly or indirectly in the completion of this study.

Lastly, the author would like to dedicate his deepest gratitude to his parents, sister, brother, housemates and also his dearest, Sin Yeng, for their support and encouragement.

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. . . . . . .

1 IT

LITERATURE REVIEW... . ...

... ... ... ....

6

Oil Palm... ... ....

6

General Overview... ...

... ... ... ... ... .. ...

6

Development ofthe Oil Palm Industry... ... ... ... .... . 7

Availability of Oil Palm Frond Biomass.. ...

.... ... ... ... . . . . . ....

8

Morphological and Chemical Characteristics of Oil Palm Fibres... .

10

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Rubberwood

... ... . ,. ...

13

General Overview.. ...

... ... ... .... .... .

13

Availability and Utilisation of Rubberwood... . .

.... ... .... ... ...

14

Morphological and Chemical Characteristics of Rubberwood...

16

Polymer ... . . .

, ... ...

18

General Overview... . . .

... .... ...

18

Types of Polymers... ... . ... . . . . .. . . .

... ..

19

Engineering Plastics... .

. . .. . .. ...

20

Polyolefin: Polypropylene... . .

. .. ... ... .

23

General Overview... ...

... .... ... ... ... .... ... ... .. ... ...

23

Properties of Pol ypropyi en e ... . . . .

, ... ... ...

24

Wood-Plastic Composite...

... ... ... ... ... ... ... ... ... ... ...

26

General Overview. ...

... ... ... ... ... ...

26

Properties of Wood-Plastic Composite... . . . .

...

29

Applications of Wood-Plastic Composite... . . ...

30

Research on WoodlFibre-Plastic Composite... . . . ... . . . . ....

33

Short Pineapple-Leaf-Fibre-Reinforced Low-Density-Polyethylene (P ALF-LDPE) Composite.. ...

.

.... ... ... .. ... ... ... 34

Sander Dust, Saw Dust, Shaving Fines and Polypropylene Composites . .. . ... . . ... . . .. . . ... . .. . . ... .

. , ... ... ... ... ..

35

Present Study . . .

, . ... ... ... ... ... ... ... ... ... ... ... ... .. , ...

36

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ill MATERIALS AND METHODS...

... ... ... ....

38

Introduction

... .. , ... ... .. , ... ... . , . .. , ... ... ... ... ... ... ... ... ... ... .. , ... ... . ,. .

38

Preparation of Raw Materials... ... ...

... ....

39

Oil Palm Frond Fibre... ...

.... ... ... .. ...

39

Rubberwood Fibre... ...

42

Polymer: Polypropylene... ...

.

...

42

Experimental Design ...

.

... ... .

, . ... " . . ..

44

Preliminary Experiment..

... ... '" .. , . .. ..

46

Preparation of Composite...

... ...

47

Blending Mixture... .

. . ...

47

Composite Pressing... .

.

...

.

...

.. ... ... .

50

Preparation of Test Samples... ...

... ..

53

Sample Conditioning... ...

.... ... ... ... ... ... ... ..

53

Sample Dimensions... ...

... ... .. ... ...

53

Evaluation of Test Samples... ...

.

...

57

Melt Flow Index

(MFI)....

... ... ... ... ... ... . 57

Thickness Measurement... ..

.

....

..

.

...

58

Tensile Properties... ...

59

Flexural Properties... ...

.

...

59

Impact Resistance...

.

..

.

...

.

...

.

...

60

Hardness... .

. . ....

61

v

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Scanning Electron Micrograph Observations... ... ... ... . 61

Statistical Analysis... ... ... .. ... ... .. 62

IV RESULTS. .. ... . . ... ... ... ... ... ... 63

Oil Palm Frond Fibre-Polypropylene Composite... ... ... .. . ... ... ... ... 67

Effect of Fibre Content on the Properties of Oil Palm Frond Fibre-Polypropylene Composite... ... ... ... ... ... .... ... ... ... ... ... ... ... ... ... . 67

Effect of Fibre Size on the Properties of Oil Palm Frond Fibre-Polypropylene Composite... ... ... ... ... ... ... ... ... ... .... ... ... ... ... .... 71

Rubberwood Fibre-Polypropylene Composite... ... .... ... ... ... ... ... ... ... 81

Effect of Fibre Content on the Properties of Rubberwood Fibre-Polypropylene Composite... ... ... ... ... ... ... ... .... ... ... ... ... ... ... .... 81

Effect of Fibre Size on the Properties of Rubberwood Fibre-Polypropylene Composite .... . , ... ... . , . . , . .. , ... '" .... , . . ,. . 86

V DISCUSSION . . ... ... . . , ... ... ... ... ... ... .. , ... ... ... ... '" ., . .. , ... .. 95

Effect of Fibre Content on the Properties of Oil Palm Frond Fibre- and Rubberwood Fibre-Polypropylene Composites ... . . . ... . '" ... . , ... , ... ... ... 95

Effect of Fibre Size on the Properties of Oil Palm Frond Fibre- and Rubberwood Fibre-Polypropylene Composites... .. . .. ... ... ... . .. ... ... .. 104

Statistical Analysis . . ... . . . . , ... ... ... ... ... ... ... ... . .. ... ... ... ... ... ... ... .. 106

VI CONCLUSIONS

AND

RECOMMENDATION . ... . . . ... . . . , . 113

Conclusions... ... . . . .. . ... ... 113

Recommendations. .. ... ... ... ... ... ... ... .... ... .. . .... . .. 115

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BIBLIOGRAPHy... .

...

... ... .. 117

VITA... ... ... ...

127

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LIST OF TABLES

Table Page

1

Oil Palm Area and Palm Oil Production in Malaysia.... ..

.

...

.

...

8

2

Estimated Total

Annual

Availability of Fronds from Year

1990

to

2000

(million dry tonnes)... ...

9

3

Fibre Dimensions of Oil Palm Residues, Douglas Fir and Rubberwood ... ..

, .. , " . ... .. , ... ... ... ... ... ... ... ... ... ... .... ... ... ..

10

4

Chemical Compositions of Oil Palm Residues, Douglas Fir, Rubberwood, Bagasse and COconut... ...

... .. ...

12

5

Area Under Natural Rubber Plantations in Malaysia

(

'000

ha)....

13

6

Projection of Production and Consumption of Rubberwood Logs

1991-201 5

(cu. m)... ...

.

..

.

..

.

15

7

Rubberwood Utilisation (prior to

1978)... ...

1 5

8

Chemical Compositions of Rubberwood...

.

..

.

17

9

Properties of Polypropylene...

.

...

25

10

Properties of Different Types of Wood Fibres and Polypropylene Composites... ... ...

37

11

Typical Properties ofPropelinas Grade

500G...

44

12 Independent Variables in the Study...

...

... ... ...

45

13

Preliminary Experimental Conditions... ...

.

...

. . .

46

14

Weight of Fibre and PP According to Their Ratios.... ...

...

47 1 5

Properties of Oil Palm Frond Fibre-Polypropylene Composite using Different Fibre Contents and Fibre Sizes ...

.

, .. , .. , .. , .. , ...

68

16

Properties of Rubberwood Fibre-Polypropylene Composite using Different Fibre Contents and Fibre Sizes ... ...

..

...

'" ..

82

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17

Effect of Fibre Contents and Fibre Sizes on the Properties of Oil

Palm Frond Fibre-Polypropylene Composites. .. ...

... ... ... ... ...

107

18

Effect of Fibre Contents and Fibre Sizes on the Properties of

Rubberwood Fibre-Polypropylene Composites... .

.. ... ... ... ...

108

19

Effect of Fibre Content on the Properties of Oil Palm Frond

Fibre-Polypropylene Composite .

...

. .

..

.

. " .,. ... ... ... ... . . . .. .

109

20

Effect of Fibre Content on the Properties of Rubberwood

Fibre-Polypropylene Composite

..

. ..

..

.. , ... ... .. , .. , ... ... ... ... ... ...

1 10

2 1

Properties of Experimental Composites and Other PP- and

PE-Filled Composites. .. .

.. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ....

1 12

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LIST OF FIGURES

Figure Page

1 Classification of Plastics... . . . ... . . . ... . . . . 21 2 Basic Structure Unit of Polypropylene... ... 23 3 Emerging Materials, Chemicals, and Fuels from Biomass... ... ... 28 4 Type V Dumbell Sample Dimensions for Tensile Test Sample

(ASTM D638-91)... ... ... ... ... ... ... ... ... ... ... ... ... .... ... 54 5 (1) Sample Dimensions and

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Allowable Range of Loading

Nose and Support Radii for Flexural Testing (ASTM

D790-96) ... ... ... ... ... ... ... ... '" ... ... ... ... ... ... ... ... ... ... ... ... .... 55 6 Sample Dimensions for IZ OD Impact Resistance Test Sample

(ASTM D256-90b) ... .. , .,. '" .. , ... '" '" .. , ... ... .. , ... ... ... 56 7 Tensile Strength (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Oil Palm Frond Fibre-Polypropylene Composite ... , . ... , .,. 69 8 Tensile Modulus (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Oil Palm Frond Fibre-Polypropylene Composite ... . " '" .. , ... ... ... ... '" .. 70 9 Flexural Modulus (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Oil Palm Frond Fibre-Polypropylene Composite ... ... ... ... .. , ... .. 72 10 IZOD Impact Resistance - Notched (J/mm) for Different Fibre

Sizes (rrun) as a Function of Different Fibre Contents (% w/w) of Oil Palm Frond Fibre-Polypropylene Composite... 73 11 ROCKWELL Hardness R for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Oil Palm Frond Fibre-Polypropylene Composite... ... ... ... ... ... ... ... ... .... 74 12 Tensile Strength (Mpa) for Different Fibre Contents (% w/w) as

a Function of Different Fibre Sizes

(

nun

)

of Oil Palm Frond

Fibre-Polypropylene Composite ... '" ... ... '" ... ... ... ... ... ... ... 75 x

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1 3

Tensile Modulus (MPa) for Different Fibre Contents (% w/w) as

a Function of Different Fibre Sizes (mm) of Oil Palm Frond

Fibre-Polypropylene Composite ... ...

' "

.

,

.

' "

....

' "

... ... ... ...

77

1 4

Flexural Modulus (MPa) for Different Fibre Contents (% w/w)

as a Function of Different Fibre Sizes (mm) of Oil Palm Frond

Fibre-Polypropylene Composite ... ... ..

, ' "

... ...

' "

...

.

..

.

..

.. ...

78

1 5

IZOD Impact Resistance - Notched (J/mm) for Different Fibre

Contents (% w/w) as a Function of Different Fibre Sizes (mm)

of Oil Palm Frond Fibre-Polypropylene Composite ...

' " .

..

79

1 6

ROCKWELL Hardness R for Different Fibre Contents (% w/w)

as a Function of Different Fibre Sizes (mm) of Oil Palm Frond

Fibre-Polypropylene Composite ... ... ...

,

.

,

.

...

. "

... ... .

, .

...

80

17

Tensile Strength (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Rubberwood

Fibre-Polypropylene Composite ... ...

,

...

.

.. ...

83

18

Tensile Modulus (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Rubberwood

Fibre-Polypropylene Composite .. ....

' " .

.

....

. ,

.

,

.

' "

...

. . . . ' " . . .

..

84

1 9

Flexural Modulus (MPa) for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Rubberwood

Fibre-Polypropylene Composite ...

,

.

, .

.

,

.... ..

,

... ...

.

.. .

.

...

.

....

85

20

IZOD Impact Resistance - Notched (J/mm) for Different Fibre

Sizes (mm) as a Function of Different Fibre Contents (% w/w)

of Rubberwood Fibre-Polypropylene Composite ...

' " .

.

. .

.

. . ,

...

87

21

ROCKWELL Hardness R for Different Fibre Sizes (mm) as a

Function of Different Fibre Contents (% w/w) of Rubberwood

Fibre-Polypropylene Composite ... ... ...

' "

..

,

..

, ' "

.

.... ... ...

88

22

Tensile Strength (MPa) for Different Fibre Contents (% w/w) as

a Function of Different Fibre Sizes (mm) of Rubberwood

Fibre-Polypropylene Composite ... ..

, .

...

' " .

.

. , . ,

.

..

.

. ,

.

.. ..

..

.

. 89

23

Tensile Modulus (MPa) for Different Fibre Contents (% w/w) as

a Function of Different Fibre Sizes (mm) of Rubberwood

Fibre-Polypropylene Composite ...

,

...

' " ' "

... ... ... ... .

.

...

90 Xl

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24 Flexural Modulus (MPa) for Different Fibre Contents (% w/w)

as

a Function of Different Fibre Sizes (mm) of Rubberwood Fibre-Polypropylene Composite... ... ... ... ... ... ... ... ... ... ... ... ... 91 25 IZOD Impact Resistance - Notched (J/mm) for Different Fibre

Contents (% w/w)

as

a Function of Different Fibre Sizes (mm) of Rubberwood Fibre-Polypropylene Composite... ... ... ... ... ... 92 26 ROCKWELL Hardness R for Different Fibre Contents (% w/w)

as

a Function of Different Fibre Sizes (mm) of Rubberwood Fibre-Polypropylene Composite... ... ... ... ... .. . ... . ... ... ... ... ... 93

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LIST

OF

PLATES

Plate Page

1 Oil Palm Fronds -Raw Material... ... ... ... ... ... ... .... . .. ... 40

2 Atmospheric Refiner - Sprout-Waldron (Model l 05A)... 40

3 Screening Vibrator... ... ... ... .. .. ... 41

4 Oil Palm Frond Fibres According to Their Sizes� (a) < 0.5

mm,

(b) 0.5 - 1

mm

,

(c)

1- 2

mm

, and (d)

>

2

mm

.. . . . ... ... ... ... 41

5 Rubberwood Fibres According to Their Sizes� (a) < 0.5

mm

, (b) 0.5 -1

mm

, (c) 1- 2 mm, and (d) > 2

mm

... . .. . . .. . ... 43

6 Granular Polypropylene Homopolymer (Propelinas 500G)... 43

7

Brabender Plasti-Corder PL-2000 (Type 2000-6)... ... ... 48

8 Brabender Mixer Type W 350 E - 2 Heating Zones... ... 49

9 Hot and Cold Press Machine ... " '" ... . .. ... 51

10 Moulded Composite.... ... ... ... . 52

11 Disintegrated Fibres (at the end of fibre bundles) Produced from Pulping Process (left: rubberwood fibre, right: oil palm frond fibre) of 1 - 2

mm

Fibre Size. Inner Horizontal Blue Lines represent 1

mm

Length. Magnification: 40X ... ... ... " . ... . 64

12 SEM showing Lack of Adhesion of Fibre and Matrix in Fractured Surface of RWF-PP (20% fibre content,

<

0.5

mm

fibre size) Composite. Magnification: 400X ... '" ... ... '" .. ' " .. 97

13 SEM showing Lack of Adhesion of Fibre and Matrix in Fractured Surface ofRWF-PP (20% fibre content,

>

2

mm

fibre size) Composite. Magnification: 800X ... ...

'" ... ... ... ... ... ...

97

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14 SEM showing Lack of Adhesion of Fibre and Matrix In Fractured Surface of OPFF-PP (20% fibre content, < 0.5 nun

fibre size) Composite. Magnification: 700X ... ... ... .. . ... ... ... .. 98 15 SEM showing Fibre Damage (Splitting) from the Tensile

Fractured Surface of RWF-PP (80% fibre content, > 2 mm fibre size) Composite. Magnification: 400X ... ... '" ... ... ... 98 16 SEM showing Fibre Damage (Peeling) from the Tensile

Fractured Surface of OPFF-PP (80% fibre content, > 2 mm fibre

size) Composite. Magnification: 1 OOX .

.

. .

. , '" ... ... ... ... ... ... ...

99

17 SEM showing Flexural Fractured Surface of OPFF-PP (20% fibre content, < 0.5 mm fibre size) Composite. Magnification:

300X... ... ... ... ... ... ... ... ...

.

....

99

18 SEM showing Flexural Fractured Surface of OPFF-PP (20% fibre content, < 0.5 mm fibre size) Composite. Magnification:

200X

... ... .

.

. . , . ... . ,. ... ... ... ... ... ... ... ... ... ... ... 100

19

SEM showing Flexural Fractured Surface of OPFF-PP (20% fibre content, < 0.5 mm fibre size) Composite. Magnification:

300X ... ... .. , ... ... ... ... ... ... ... ... ... ... ... ... ... 100 20 SEM showing the Inability of IZ OD Impact Test Piece to

Absorb Impact Energy

in

Fractured Surface of RWF-PP (20% fibre content, < 0.5 mm fibre size) Composite. Magnification:

450X ... ... '" ... ... .. , ... ... '" .. , ... ... ... .. , ... ... .... 102 21 SEM showing the Inability of IZ OD Impact Test Piece to

Absorb Impact Energy in Fractured Surface of OPFF-PP (20% fibre

content,

<

0.5

mm

fibre size) Composite.

Magnification:

250X ... ... '" ... ... ... ... ... , '" .. , '" ... . ,. '" ... ... ... ... ... 102 22 SEM showing the Surface of RWF-PP (80% fibre content, < 0.5

mm fibre size) Composite Prepared for ROCKWELL Hardness

Testing. Magnification: 300X ... ... ... ... ,. '" ... ... .. 103 23 SEM showing the Surface of OPFF-PP (80% fibre content, > 2

mm fibre size) Composite Prepared for ROCKWELL Hardness

Testing. Magnification: 200X ... . , . ... ... ... '" ... ... ... . .. ... ... .. 103

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ABS: ASTM: DOS: FELCRA: FELDA: HOPE: JIS: MRRDB: p: PMMA: PP: PYA: RISDA: wt: LIST OF ABBREVIATIONS Acrylonitrile-butadiene-styrene

American Society for Testing and Materials Department of Statistic

Federal Land Consolidation and Rehabilitation Authority Federal Land Development Authority

High density polyethylene Japanese Industrial Standard

Malaysian Rubber Research Development Board probability

Polymethyl methacrylate Polypropylene

Polyvinyl acetate

Rubber Industries of Smallholders' Development Authority weight

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia

in

fulfilment of the requirements for the degree of Master of Science.

FffiRE-PLASTIC COMPOSITES:

OIL PALM FROND AND RUBBER WOOD FffiRES BLENDED WITB POLVPROPYLENE

By

LIEW KANG CHIANG

MARCB1998

Chairman : Dr. Jalaluddin Barun

Faculty : Forestry

Natural lignocellulosic fibres have become more important nowadays

because "new" types of composite material can be produced from them. The

. objectives of this study are to evaluate the suitability of producing

fibre-polypropylene composite using oil palm frond fibre and rubberwood fibre. The

effects of different fibre size and fibre content on the physical and mechanical

properties of the composite produced are assessed to give an insight into

fibre-matrix adhesion and fibre damages.

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In this study, crude fibres of oil palm fronds were atmospherically refined

into fine fibres whilst rubberwood fibres were obtained from a local fibreboard

plant. These fibres were later screened into different sizes:

<

0.5 mm, 0.5 - 1 mm, 1

-2

mm and

> 2

mm. The screened fibres were melt-blended with polypropylene at

different ratios in a Brabender Plasti-Corder equipped with a mixer of type

W

350

E

-

2

Heating Zones. The mixing condition

was

set at a rotor speed of 30 rpm at

180°C for 30 minutes. Moulded composites were prepared for evaluation of tensile,

flexural, IZOn impact resistance - notched and ROCKWELL hardness according to

ASTM

standards.

Results indicate that both oil palm frond and rubberwood composites

showed reduction in tensile strengths but increment in tensile modulus as fibre

content increase. Oil palm frond composite possessed higher tensile strength

and

modulus than rubberwood composite.

As

fibre size increased, the strength of both

types of composites also increase. Flexural modulus for oil palm frond and

rubberwood composites increased with fibre content. Rubberwood composite using

coarser fibre sizes (1

-2

mm,

> 2

mm) exhibit higher modulus. Unlike rubberwood,

oil palm frond composite shows higher modulus when finer « 0.5 mm, 0.5 - 1 mm)

fibres were used. IZOn impact resistance - notched test piece showed a decreasing

impact for oil palm frond composite as the fibre content increases but rubberwood

composite experienced the opposite effect. An increase in fibre size increases the

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impact strength of both types of composites.

ROCKWELL

hardness decreased for

oil palm frond and rubberwood composites

as

fibre content and fibre size increases.

All evaluations are statistically analysed at p<O.05. Supportive photographic

evidences of the above results are shown by Scanning Electron Micrographs.

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Abstrak tesis yang dikemukakan kepada Senat Universiti

Putra

Malaysia sebagai

memenuhi keperluan untuk ijazah Master Sains.

KOMPOSIT GENTIAN-PLASTIK:

ADUNAN GENTIAN PELEPABKELAPA SAWIT DAl�KAYUGETAH DENGAN POL�ROpaENA

Oleh

LIEW KANG CHIANG

MAC 1998

Pengerusi : Dr. Jalaluddin Barun

Fakulti : Perhutanan

Bahan lignoselulosa telah menjadi semakin penting pada masa kini kerana

komposit "barn" boleh dihasilkan daripadanya Objektif penyelidikan ini adalah

. untuk menilai kesesuaian dalam menghasilkan komposit gentian-polipropilena

dengan menggunakan gentian pelepah kelapa sawit and gentian kayu getah. Kesan

saiz gentian dan kandungan gentian yang berlainan dalam sifat-sifat fizikal dan

mekanikal pada komposit juga dikaji bagi memberi pandangan ke dalam perekatan

gentian-matrik dan kerosakan gentian.

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Dalam penyelidikan ini, gentian kasar daripada pelepah kelapa sawit dikisar

secara atmosfera kepada gentian balus sementara gentian kayu getah diperolehi dari

kilang tempatan yang menghasilkan papan gentian.

Gentian-gentian ini

kemudiannya ditapis kepada saiz berlainan�

<

0.5 mm, 0.5 - 1 mm, 1 -

2

mm dan

>

2

mm. Gentian ini diadun-Iebur dengan polipropilena menggunakan "Brabender

Plasti-Corder" yang dilengkapi dengan pengadun jenis

W

350

E -2

Zon Pemanasan,

pada kandungan gentian berlainan. Keadaan adunan ditetapkan pada kelajuan 30

rpm pada 180°C untuk 30 minit. Komposit dibentuk dan disediakan untuk ujian

tegangan, lenturan, ketahanan impak IZOD - berlekuk dan kekerasan ROCKWELL

berdasarkan piawaian ASTM.

Keputusan memberi gambaran yang kedua-dua komposit pelepah kelapa

sawit dan kayu getah menunjukkan pengurangan dalam kekuatan tegangan tetapi

kenaikan dalam modulus ,tegangan apabila kandungan gentian meningkat.

Komposit pelepah kelapa sawit mempunyai kekuatan tegangan dan modulus yang

lebih tinggi daripada komposit kayu getah.

Apabila saiz gentian meningkat,

kekuatan kedua-dua jenis komposit juga b

ertam

bah.

Modulus len

turan

untuk

komposit pelepah kelapa sawit dan kayu getah meningkat dengan kandungan

gentian. Komposit kayu getah menggunakan saiz gentian yang Iebih kasar (1 -

2

rom, >

2

mm)

mempamerkan modulus yang tinggi. Berlainan dengan kayu getah,

komposit pelepah kelapa sawit menunjukkan modulus yang Iebih tinggi bila gentian

yang Iebih halus « 0.5

mm,

0.5 1 mm) digunakan. Ketahanan impak IZOD

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berlekuk menunjukkan penurunan impak untuk komposit pelepah kelapa sawit bila kandungan gentian meningkat tetapi komposit kayu getah mengalami kesan yang bertentangan. Kenaikan dalam saiz gentian juga menaikkan nilai impak untuk kedua-dua jenis komposit. Kekerasan ROCKWELL menurun untuk komposit pelepah kelapa sawit

dan

kayu getah apabila kandungan gentian

dan

saiz gentian meningkat.

Semua penilaian dianalisa secara statistik pada p<O.OS. Bukti sokongan untuk keputusan di atas diperkuatkan melalui gambar "Scanning Electron Micrographs" .

(23)

CHAPTER I

INTRODUCTION

In the early days, human beings used wood to make their tools, weapons and

shelter to keep them from the sun and rain. Wood possesses flexible cellulosic

fibres arranged in an amorphous matrix of lignin and hemicellulosic polymer. This

renewable resource has changed in terms of its properties over the years through the

expansion of man's knowledge such as making the wood stronger and last longer.

They have also modified the wood through coating or filling the porous structure of

wood with

tars,

pitches, creosote, resins and salts (Meyer, 1982).

In

short, human

beings have learnt

to

modify wood to produce better and more expensive products.

Due to their characteristics, products made from hydrophilic lignocellulosic

material such as wood and non-wood vary greatly in mechanical properties and

dimensional stability. The composites produced are more susceptible to moisture

making them easily decayed by fungi and other biodegradation agents.

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2

Furthermore, due to constant change in weather conditions, their dimensions

would be altered as a result of fibre movements which would in tum make it

unstable. Over the years, extensive research were carried out to incorporate

lignocellulosic materials with different kinds of plastics to improve its inherent

properties. With the introduction of thermoplastic polymer, these works take

another route of application. These thermoplastic polymers are strong, lightweight,

durable and resistant to microorganisms. Furthermore, synthetic plastics possess a

hydrophobic character whereby they inhibit natural enzymatic activities. Chemical

treatments have been used on wood

to improve its strength and stability through

chemical impregnation, acetylation of hydroxyl groups, cross-linking of the

cellulose with formaldehyde, cyanoethylation, ethylene oxide addition

to the

hydroxyl groups, ozonolysis, propiolactone grafting of side chains, polyethylene

glycol (pEG) bulking of cell walls and phenol-formaldehyde treatments (Meyer,

1982). Through these treatments, improvements on wood properties were achieved

and many new products were developed.

In

recent years, the abundance of oil palm and rubber tree biomass have

posed a disposal problem

to plantation owners.

Currently, the abundant

lignocellulosic resources are either burnt, thus causing pollution to the environment,

or just left

to deteriorate at the plantation site for nutrient cycling. With the ever

changing technology nowadays, fibres produced from these resources can be put

(25)

3 into better use as they can be converted into composite products such as

particleboard and fibreboard.

Apart from the conventional particleboard and

medium density fibreboard, these fibres can also be incorporated into plastic

material. Usually, wood flour are used as a cheap filler in the matrix. The cost,

availability, renewability, and recyclability of lignocellulosics offer the production

of large volume, low-cost, high performance structural composites which are most

suited to the automobile industry and durable goods market (Narayan, 1992).

Research has shown that oil palm biomass have a potential future for the production

of composite products and into commercialisation. Among the areas studied were

conversion of oil palm trunk into sawn timber and veneer (Ho

et.

aI., 1 985),

particleboards (Chew and Ong, 1985; Lim and Khoo, 1986), cement-board (Lim

and Khoo, 1986; Rahim

et.

ai., 1991), gypsum-bonded particleboards (Khozirah

et.

aI., 1991), pulp and paper (Mohd. Nor, 1985; Khoo and

Lee,

1985) and animal feed

(Ismail

et.

ai., 1991; Abu Hassan

et.

ai., 1991).

Wood or non-wood fibres

can

Fibre-Plastic Composites: Oil Palm Frond and Rubberwood Fibres Blended with Polypropylene

UNIVERSITI PUTRA MALAYSIA