faculty of resource science and technology … of cellulose fibers from...isolation of cellulose...

ISOLATION OF CELLULOSE FIBERS FROM BANANA LEAVES

Premanarayani Menon D/O Narayanan Nair

Bachelor of Science with Honours

(Resource Chemistry)

2013

Faculty of Resource Science and Technology

Isolation of Cellulose Fibers from Banana Leaves

Premanarayani Menon D/O Narayanan Nair (27964)

A final report submitted in the fulfillment of the requirement for the degree of

Bachelor of Science with Honours

(Resource Chemistry)

Supervisor: Dr. Chin Suk Fun

Co-Supervisor: Associate Professor Dr. Pang Suh Cem

Resource Chemistry

Department of Chemistry


Universiti Malaysia Sarawak

2013

I

Acknowledgment

First and foremost I would like to express my gratitude to my supervisor Dr. Chin Suk Fun for

her supervision, support and insightful comments that have helped me to improve the quality

of this project. Without her help, I would not be able to experience a remarkable progress in

my final thesis. I really appreciate her effort in assisting me to accomplish this project

successfully.

I would like to thank the Department of Chemistry, Universiti Malaysia Sarawak for giving

me the opportunity to fulfill my Final Year Project. I am thankful for all the materials,

equipment, instruments and other facilities which were provided in order to complete my

project.

I would like to appreciate Physical Chemistry lab group members especially Ms. Ain and Ms.

Fiona for their assistance and support throughout the project. I am grateful for the valuable

experience, knowledge and laboratory skills that I have attained throughout this project.

Finally, I would like to thank my friends and family for their effort and guidance for the

project development. We have exchanged knowledge and helped each other in order to finish

our task. Their encouragement had given me the motivation to complete this project. I hope

God bless all those who have helped me in the process of completing my final year project.

II

Declaration

I declare that this thesis entitled “Isolation of Cellulose Fibers from Banana Leaves” is the

result of my own research except as cited in the references. The thesis has not been accepted

for any degree and is not concurrently submitted in candidature of any other degree.

Signature ……………………………………

Name …………………………………….

Date ……………………………………..

III

Table of Content

Acknowledgement ....................................................................................................................... I

Declaration.................................................................................................................................. II

Table of contents .......................................................................................................................III

List of Abbreviations .................................................................................................................. V

List of Tables ............................................................................................................................ VI

List of Figures .......................................................................................................................... VII

Abstract ........................................................................................................................................1

1.0 Introduction ...........................................................................................................................2

1.1 Problem Statement .....................................................................................................4

1.2 Objectives ..................................................................................................................5

1.3 Hypothesis .................................................................................................................5

2.0 Literature Review ..................................................................................................................6

2.1 Cellulose ....................................................................................................................6

IV

2.2 Ultrasonic technique for isolation of cellulose ..........................................................7

2.3 Morphology of the chemical-purified cellulose ........................................................9

2.4 Influence of acid hydrolysis reaction.......................................................................10

2.5 Mixed Acid Treatment ............................................................................................12

2.6 Conventional process of isolation of cellulose ........................................................13

2.7 Isolation of cellulose from grape skin .....................................................................14

2.8 Isolation of cellulose from palm kernel cake...........................................................15

2.9 Isolation of α-cellulose from wholewood material ..................................................17

3.0 Materials and Methods ........................................................................................................20

3.1 Materials ..................................................................................................................20

3.2 Isolation of cellulose ................................................................................................20

4.0 Results and Discussion ........................................................................................................22

4.1 Treatment of sample with acidified sodium chlorite ...............................................22

4.1.1 Chemical composition analysis with FTIR .............................................23

4.1.2 Surface morphology analysis....................................................................29

4.2 Treatment of delignified sample with sodium hydroxide .......................................32

4.2.1 Chemical composition analysis with FTIR ..............................................33

4.2.2 Surface morphology analysis with FTIR ..................................................36

4.3 Effect of ultrasonication time on the morphology of isolated cellulose ..................42

5.0 Conclusion ...........................................................................................................................46

6.0 Reference .............................................................................................................................48

V

List of Abbreviations

Methanoic acid HCOOH

Ethanoic acid CH3COOH

Sodium chlorite NaClO2

Sodium hydroxide NaOH

Micrometer µm

Nanometer nm

Kilojoule per mole Kj/m

Kilohertz KHz

Mililitre ml

Weight percent wt%

Power W

Hours hrs

Degree Celcius 0C

Hydrogen Peroxide H202

Response Surface Methodology RSM

Fourier Transform Infrared Spectroscopy FTIR

Scanning Electron Microscope SEM

Multiple Sample Isolation System for Solids MSISS

Polytetrafluoroethylene PTFE

VI

List of Tables

Table Page

Table 1: Parameters involved in the chemical pretreatment of sample 21

(Concentration of acidified sodium chlorite and reaction duration)

Table 2: Parameters involved in chemical pretreatment of sample 21

(Concentration of sodium hydroxide and reaction duration)

VII

List of Figures

Figure Page

Figure 1: Procedure for individualizing cellulose nanofibers 8

Figure 2: Structure of hemicellulose 14

Figure 3: Structure of S, H and G-lignin 15

Figure 4: Structure of Cellulose 16

Figure 5: Structure of Multiple Sample Isolation System For Solids (MSISS) 18

Figure 6a: FTIR spectra of the untreated sample 24

Figure 6b: FTIR spectra of the sample treated with 2 wt% of NaClO2 for 1hr 24

Figure 6c: FTIR spectra of the sample treated with 2 wt% of NaClO2 for 3hrs 24


Figure 7b: FTIR spectra of the sample treated with 2 wt% of NaClO2 for 5hrs 25

VIII



Figure 8b: FTIR spectra of the sample treated for 1hr with 2 wt% of NaClO2 26

Figure 8c: FTIR spectra of the sample treated for 1hr with 4 wt% of NaClO2 26


Figure 9b: FTIR spectra of the sample treated for 1hr with 6 wt% of NaClO2 27

Figure 9c: FTIR spectra of the sample treated for 1hr with 8 wt% of NaClO2 27

Figure 9d: FTIR spectra of the sample treated for 1hr with 10 wt% of NaClO2 27


Figure 10b: FTIR spectra of the sample treated with 10 wt% of NaClO2 for 1hr 28


Figure 11a: SEM images of sample treated with 2 wt% of NaClO2 for 1hr 29

IX

Figure 11b: SEM images of sample treated with 2 wt% of NaClO2 for 3hrs 29

Figure 11c: SEM images of sample treated with 2 wt% of NaClO2 for 5hrs 29

Figure 11d: SEM images of sample treated with 2 wt% of NaClO2 for 7hrs 29

Figure 12a: SEM images of sample treated for 1hr with 2 wt% of NaClO2 31

Figure 12b: SEM images of sample treated for 1hr with 4 wt% of NaClO2 31

Figure 12c: SEM images of sample treated for 1hr with 6 wt% NaClO2 31

Figure 12d: SEM images of sample treated for 1hr with 8 wt% of NaClO2 31

Figure 12e: SEM images sample treated for 1hr with 10 wt% NaClO2 31

(2000 x magnification)

Figure 12f: SEM images sample treated for 1hr with 10 wt% NaClO2 31


Figure 13a: SEM images of sample treated with 10 wt% of NaClO2 for 1hr 31

Figure 13b: SEM images of sample treated with 10 wt% of NaClO2 for 3hrs 31

X


Figure 14b: FTIR spectra of the sample treated with 2 wt% of NaOH for 1hr 33

Figure 14c: FTIR spectra of the sample treated with 2 wt% of NaOH for 3hrs 33

Figure 14d: FTIR spectra of the sample treated with 2 wt% of NaOH for 5hrs 33

Figure 14e: FTIR spectra of the sample treated with 2 wt% of NaOH for 7hrs 33


Figure 15b: FTIR spectra of the sample treated for 1hr with 2 wt% of NaOH 34

Figure 15c: FTIR spectra of the sample treated for 1hr with 4 wt% of NaOH 34

Figure 15d: FTIR spectra of the sample treated for 1hr with 6 wt% of NaOH 34


Figure 16b: FTIR spectra of the sample treated with 8 wt% of NaOH for 1hr 35

Figure 16c: FTIR spectra of the sample treated with 10 wt% of NaOH for 1hr 35

XI

Figure 16d: FTIR spectra of the sample treated with 10 wt% of NaOH for 3hrs 35

Figure 17a: SEM images of sample before NaOH treatment 36

Figure 17b: SEM images of sample after NaOH treatment 36

Figure 18a: SEM images of sample treated with 2 wt% of NaOH for 1hr 37

(800 x magnifications)

Figure 18b: SEM images of sample treated with 2 wt% of NaOH for 1hr 37


Figure 19a: SEM images of sample treated with 2 wt% of NaOH for 3hrs 37


Figure 19b: SEM images of sample treated with 2 wt% of NaOH for 3hrs 37






XII







Figure 22b: SEM images of sample treated with 4 wt% of NaOH for 1hr 39


Figure 23a: SEM images of sample treated with 6 wt% NaOH for 1hr 39


Figure 23b: SEM images of sample treated with 6 wt% NaOH for 1hr 39


Figure 24a: SEM images of sample treated with 8 wt% NaOH for 1hr 40


Figure 24b: SEM images of sample treated with 8 wt% NaOH for 1hr 40


XIII









Figure 27a: Morphology of chemically isolated cellulose after ultrasonication 43

of 30 seconds

Figure 27b: Morphology of chemically isolated cellulose after ultrasonication 43

of 60 seconds

Figure 27c: Morphology of chemically isolated cellulose after ultrasonication 43

of 90 seconds

Figure 27d: Morphology of chemically isolated cellulose after ultrasonication 43

of 120 seconds

XIV

Figure 27e: Morphology of chemically isolated cellulose after ultrasonication 43

of 150 seconds

Figure 27f: Morphology of chemically isolated cellulose after ultrasonication 43

of 180 seconds

Figure 27g: Morphology of chemically isolated cellulose after ultrasonication 43

of 210 seconds

Figure 27h: Morphology of chemically isolated cellulose after ultrasonication 43

of 240 seconds

Figure 28: Effect of ultrasonication on the average diameter of isolated 45

Cellulose fiber

1

Isolation of Cellulose Fibers from Banana Leaves

N. Premanarayani Menon

Resource Chemistry Programme


Universiti Malaysia Sarawak

ABSTRACT

Banana leaves are one of the abundant agricultural wastes from banana plants cultivation.

Thus, isolation of cellulose from banana leaves aims to reduce the waste production.

Celluloses have received tremendous attention due to its potential application as reinforcing

agent. Cellulose fibers from banana leaves have been isolated and characterized by FTIR and

SEM. Banana fibers were treated with acidified sodium chlorite (NaClO2) and sodium

hydroxide (NaOH) to remove lignin and hemicellulose respectively. The chemical treatment

was subjected under different conditions, to study the effects of concentration, reaction

duration on the removal of lignin and hemicellulose as well as on the surface morphology of

the resultant cellulose fibers. Treatment of sample with 10 wt% of NaClO2 for 3 hours and 10

wt% of NaOH for 3 hours is the optimum conditions obtained from the study. Furthermore,

the morphology of the isolated cellulose was studied across different ultrasonication time. The

increase in ultrasonication time from 30 seconds to 240 seconds has resulted in the reduction

of the diameter of cellulose fibers.

Keywords: Banana leaves, isolation, cellulose fiber.

ABSTRAK

Daun pisang merupakan salah satu sisa bahan buangan pertanian selepas penanaman pokok

pisang. Justeru, pengekstrakan selulosa daripada daun pisang bertujuan untuk

mengurangkan sisa-sisa bahan buangan. Kelebihan sellulosa terfokus dalam aplikasi

sellulosa sebagai penguat sellulosa. Gentian selulosa daripada daun pisang telah diekstrak

dan dicirikan oleh FTIR dan SEM. Gentian daun pisang telah dirawat dengan natrium klorida

(NaClO2) dan natrium hidroksida (NaOH) untuk membuang lignin dan hemiselulosa masing-

masingnya. Rawatan kimia telah dijalankan dalam keadaan yang berbeza, untuk mengkaji

kesan kepekatan, masa tindak balas terhadap penyingkiran lignin dan hemiselulosa serta

perubahan terhadap morfologi permukaan gentian selulosa. Rawatan sampel dengan 10 %

NaClO2 selama 3 jam dan 10 % NaOH selama 3 jam merupakan keadaan optimum yang

diperolehi daripada kajian ini. Tambahan pula, kesan perbezaan masa ultrasonikasi terhadap

morfologi selulosa telah dikaji. Didapati bahawa diameter gentian selulosa telah menurun

apabila masa ultrasonikasi meningkat dari 30 saat kepada 240 saat.

Kata Kunci: Daun pisang, gentian selulosa, pengekstrakan.

2

1.0 Introduction

Isolation of Cellulose from agricultural wastes has gained a lot of attention from the scientists

and researchers due to its high demand in paper industries, food industries, pharmaceutical

and cosmetics. Agricultural by products such as banana leaves considered as an alternative

source for the production of cellulose. In tropical and sub-tropical region, bananas are

produced in large amount (Aziz et al., 2011). Banana leaves are used for wrapping food and

serving food (Mohapatra et al., 2010). However, after that the leaves are thrown away and this

generates agriculture wastes. Accumulation of agriculture waste has affected the environment.

Cellulose is an organic compound and it is a linear polysaccharide that is commonly found as

main constituent of primary cell wall of green plants (Saxena & Brown, 2008). According to

Habibi et al. (2008), cellulose represents about 1.5 x 1012

tons of the total biomass produced

in nature in a year. Thus, cellulose can be considered as an unlimited source and it can be used

to manufacture eco-friendly products. Cellulose is restored by nature through photosynthesis.

However, it is depleted in the form of pre-harvest and post-harvest agricultural losses and

wastes of food processing industry. In developing countries, like India, a major portion of the

cellulose generated remains unutilized and goes for wastes, namely in the forms of waste from

forest resources, wood, paper, and board after human uses, pulp, textile, agriculture, and food

industries (Elanthikkal et al., 2010)

In recent studies, many researches have been done in the aspect of characterization of

cellulose, hemicelluloses and lignin. Besides that, studies were carried on their usage, sources

3

and composition of cellulosic and lignocellulosic wastes of agriculture and food industry

(Nada et al., 2010). Furthermore, conversion of cellulose into value-added products of food

and medical application and constraints in their conversions were reviewed in details. For

example, microcrystalline cellulose is expected to act as water retainer, suspension stabilizer,

or as a reinforcing agent for products such as medical tablet (Nuruddin et al., 2011). The

extending property of cellulose which includes high stiffness and high degree of crystalline

makes it ideal as reinforcing agent (Bhattacharya et al., 2008).

The research covers the production of cellulose for various purposes which includes

reinforcement in composite and pulps for producing paper. Besides that, these cellulose

wastes have an enormous potential to be utilized for the production cellulosic material such as

cellulose biofilms and cellulose nanoparticles. Cellulose can be used as a raw material for

production of commodity product in industries (Gupta et al., 2012). Besides that, it has the

potential to produce derivative products such as rayon (Shin et al., 2012).

This study has practical significances. A proper method is developed to separate the cellulose

from the mixture of banana fibers. Methods are developed and the parameters are studied in

order to improve the quality of the results obtained. The minimum concentration of NaClO2

and NaOH at a fixed reaction duration required for a complete removal of lignin and

hemicellulose was determined respectively. On the other hand, the minimum reaction duration

of NaClO2 and NaOH treatment at a fixed concentration was also determined respectively.

Finally, the reaction condition that reveals the complete removal of hemicellulose and lignin

and better separation of cellulose fibers was chosen as the optimum condition for isolation of

4

cellulose from banana leaves. Furthermore the effect of ultrasonication time on the

morphology of the isolated cellulose was investigated.

1.1 Problem Statement

1. Accumulation of agriculture wastes including banana leaves pose potential environmental

problems.

2. Cellulosic fibers from banana leaves have potential use and can be applied in various

fields.

3. The banana fibers consist of a mixture of components. It is required to remove other

components such as lignin and hemicelluloses in order to obtain cellulose fibers.

4. Surface morphology and chemical composition of cellulose are affected by various

parameters involved in pretreatment and isolation process.

5

1.2 Objectives

The objectives of this study are:

(i) To isolate cellulose from banana leaves.

(ii) To study the effects of the parameters such as the duration of chemical treatment,

concentration of chemicals on the chemical composition and surface morphology of

cellulose.

(iii) To study the effect of ultrasonication time on the surface morphology of isolated

cellulose.

1.3 Hypothesis

The hypothesis of this study is that the lignin and hemicellulose from the mixtures are

removed completely and more individualized cellulose can be obtained by optimizing the

reaction conditions.

6

2.0 Literature Review

2.1 Cellulose

Cellulose is a type of natural fiber. Cellulosic fibers that are produced by plants are referred as

natural fibers. Natural fibers have many advantages which includes low cost, low density,

high toughness, acceptable specific strength properties and biodegradability (Lee et al., 2007).

The composition of natural fibers includes cellulose, lignin and hemicelluloses. Others

components such as pectin, pigments and extractives can be found in lower quantities. The

rigid microfibrillated cellulose is embedded in a soft matrix mainly composed of lignin and

hemicelluloses. It is abundantly found in wood or other lignocellulosic plant (Wang et al.,

2010).

Cellulose can only be dissolved in certain specific complexes and high concentrated acid and

base due to its degree of polymerization and partial crystalline structure. Therefore it does not

easily dissolve in common solvents (Klemm et al., 2005). Cellulose is a linear polymer of

poly-β (1 4) D-glucose (Zuluaga et al., 2007). It is composed of both amorphous and

crystalline region. It has secondary OH at C-2, secondary OH at C-3 and primary OH at C-6

position (Kadla & Gilbert, 2000). Besides that, cellulose can form strong intermolecular and

intramolecular hydrogen bond. Thus it does not melt before thermal degradation (Oh et al.,

2005a). Cellulose also acts as a structural polymer.

7

In order to fulfill the demand of industrial use, cellulose is often modified in terms of its

physical and chemical properties as well as enzymatic means. Cellulose exhibit changes in its

solubility, properties and behavior of the polymer. The chemical modification that takes place

is based on the free hydroxyl group in the glucopyranose units (Oh et al., 2005b). This results

in the formation of cellulose derivatives. One of the industrial applications includes the

production of rayon through viscose process where cellulose is converted to sodium cellulose

by treatment with sodium hydroxide (Oh et al., 2005b).

2.2 Ultrasonic technique for isolation of cellulose

Cellulose nanofibers were isolated from wood by using high intensity ultrasonification

combined with chemical pretreatments (Chen et al., 2010). Matrix substances such as

hemicellulose and lignin are mixed together with the cellulose. Thus, chemical methods were

used to separate the matrix from cellulose nanofibers. After the chemical treatment, the

compositional changes were revealed through FTIR spectroscopic analyses. The prominent

peak at 1731 cm-1

represents the acetyl and uronic ester groups of the hemicelluloses or the

ester linkage of carboxylic group of the ferulic and p-coumeric acids of lignin and/or

hemicelluloses (Chen et al., 2010). On the other hand, the peak at 1513 cm-1

represents the

carbon-carbon double bond stretch of the aromatic rings of lignin (Elanthikkal et al., 2010).

The absence of these peaks in the treated fibers indicates the effective removal of lignin and

hemicelluloses (Elanthikkal et al., 2010).

8

The ultrasonic treatment was carried out with an output power of 400, 800, 1000 and 1200W

to isolate the nanofibers. Increase in ultrasonic power from 400W to 1200W was accompanied

by the increase in dispersion of the nanofibers suspension (Chen et al., 2010). Ultrasonic

energy was transferred to cellulose through a process called cavitation. Cavitation refers to the

formation, growth, and violent collapse of cavities in water. The energy transferred is called as

sonochemistry which is approximately 10-100 kJ/mol. The energy transferred is within the

hydrogen bond energy scale. The impact of ultrasonic energy disintegrates the micron sized

cellulose fibers into nanofibers. The nanofibers obtained were with wide distribution in width

due to the complicated multilayered structure of plant fibers and the intermolecular hydrogen

bond (Chen et al., 2010). Ultrasonic technique produced cellulose with higher surface area.

Finally, colloidal suspensions were produced (Chen et al., 2010) (Figure 1).

Figure 1: Procedure for individualizing cellulose nanofibers (Chen et al., 2010)

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