Properties of chitin whisker reinforced poly(acrylic acid) composites

198 Pages·2015·6.24 MB·English

by  Michael Ofem

PROPERTIES OF CHITIN WHISKER REINFORCED
POLY(ACRYLIC ACID) COMPOSITES

A thesis submitted to The University of Manchester for
the degree of Doctor of Philosophy in the Faculty of
Engineering and Physical Sciences

2015

Michael Ofem

School of Materials
TABLE OF CONTENT

TABLE OF CONTENTS 2
LIST OF FIGURES 5
LIST OF TABLES 10
LIST OF SYMBOLS 12
LIST OF ABBREVIATIONS 13
ABSTRACT 15
DECLARATION 16
COPYRIGHT STATEMENT 17
ACKNOWLEDGEMENTS 18

CHAPTER 1 Introduction 19
1.1 Background 19
1.2. Statement of Problem 21
1.3. Objectives 21
1.4 Thesis Structure 22
1.5 References 22

CHAPTER 2 Literature Review 25
2.1 Chitin 25
2.1.1 Chitin Sources 25
2.1.2 Extraction of Chitin 27
2.1.2.1 Chemical Extraction of Chitin 27
2.1.2.2 Biological Extraction of Chitin 28
2.1.3 Deacetylation of Chitin 31
2.1.4 Chemical Structure of Chitin 32
2.1.5 Applications of Chitin 33
2.2 Chitin Whiskers 34
2.2.1 Preparation of Chitin Whiskers 36
2.3 Mechanical Properties of CHW Based Nanocomposites 38
2.4 Thermal Properties 43
2.5 Other Properties of Chitin 44
2.6 Poly(acrylic acid) 47
2.7 Introduction to Raman Spectroscopy 50
2.7.1 Raman Effect 50
2.7.2 Classical Theory and Quantum Mechanical Approach of Raman
Scattering 52
2.7.3 Polarised Raman Spectroscopy 54
2.7.4 Applications of Raman Spectroscopy 56
2.7.5 Application of Raman Spectroscopy to Deformation of Cellulose
Reinforced Nanocomposites 58
2.8 CaCO /CHW Hybrid Composites 61
3
2.9 References 65
2
TABLE OF CONTENT

CHAPTER 3 Experimental methodology 77
3.1 Materials 77
3.2 Processing of Materials 78
3.2.1 Purification of Chitin 78
3.2.2 Preparation of Chitin Whisker (CHW) 78
3.3 Preparation of Pure Chitin and Pure Poly(acrylic acid) Films 79
3.4 Preparation of Chitin Whisker Reinforced Poly( acrylic acid) Composites 79
3.5 Preparation of CaCO /Chitin/PAA Composites 82
3
3.6 Characterisation of Composites 82
3.6.1 X-Ray Diffraction 82
3.6.2 Raman Spectroscopy 83
3.6.2.1 Calibration 83
3.6.2.2 Molecular Orientation 84
3.6.3 Mechanical Characterisation 85
3.6.3.1 Tensile Deformation 85
3.6.3.2 Raman Deformation 87
3.7 Scanning Electron Microscopy 87
3.8 Transmission Electron Microscopy and Image Analysis 88
3.9 Thermogravimetric analysis 88
3.10 Differential Scanning Calorimetry 88
3.11 References 89

CHAPTER 4 Raman and X-Ray Diffraction Characterisation 91
4.1 Introduction 91
4.2 Raman 91
4.2.1 Effect of Chitin Loading on Raman Spectra 93
4.3 XRD Characterisation 98
4.4 Conclusions 105
4.5 References 105

CHAPTER 5 Mechanical Properties of Chitin Whiskers Reinforced Poly (acrylic acid) 109
5.1 Introduction 109
5.2 Morphological Properties of CHW 109
5.3 Mechanical Properties 111
5.3.1 Effect of matrix molecular weight on tensile properties 116
5.3.2 Effect of Strain Rate on Mechanical Properties 119
5.3.3 Modeling of the Mechanical Behaviour 122
5.4 Morphological Characterisations of Free and Fractured Surfaces of Film 125
5.5 Micromechanical Deformation of Microfibrillated Chitin Film and Composites
128
5.5.1 Deformation of Microfibrillated Chitin film and Composites 128
5.5.2 Determination of the Modulus of CHW 132
3
TABLE OF CONTENT

5.6 Conclusions 135
5.7 References 135

CHAPTER 6 Thermal Properties of Chitin Whisker Reinforced Poly (acrylic acid) 141
6.1 Introduction 141
6.2 Thermogravimetric Analysis (TGA/DTGA) 141
6.3 DSC Analysis 148
6.4 Conclusions 154
6.5 References 155

CHAPTER 7 Preparation and Characterization of Chitin Whisker reinforced
Poly(acrylic acid)/Calcium Carbonate 159
7.1 Introduction 159
7.2 Raman Spectroscopy 159
7.3 X-Ray Diffraction of Chitin Whiskers Reinforced CaCO /Composites 165
3
7.4 Scanning Electron Microscopy Morphology 172
7.5 Conclusions 175
7.6 References 175

CHAPTER 8 Mechanical and Thermal Properties of Chitin Whiskers Reinforced
Poly(acrylic acid)/Calcium Carbonate. 179
8.1 Introduction 179
8.2 Mechanical Properties 179
8.3 Thermogravimetric Analysis (TGA/DTGA) 182
8.4 DSC Analysis 185
8.5 SEM of Fracture Surfaces 190
8.6 Conclusions 191
8.7 References 192

CHAPTER 9 Conclusions and Suggestions for Future Work 195
9.1 Conclusions 195
9.2 Suggestions for Future Work 196
9.2.1 Determination of Young’s Modulus of a Single Filament of Chitin
Whisker using Atomic Force Microscopy 196
9.2.2 TEMPO-Mediated Surface Oxidation of Chitin Whiskers 197
9.2.3 Effect of different Raman Polarisation Configurations on Stress Transfer
197
9.3 References 198

ords ounts 47,598
4
LIST OF FIGURES

Figure 2.1- Chitin (%) present in different organisms (superscripts: abased on the
weight of the organic cuticle; bbased on the dry weight of the body; cbased on the
fresh weight of the body; dbased on the total weight of the cuticle; ebased on the dry
weight of the cell wall). [Kaur and Dhillon, 2013] ………………………………………………….... 25
Figure 2.2- Schematic preparation of chitin and chitosan by chemical isolation from
raw material [Aranaz et al., 2009] …………………………………………………………………………… 28
Figure 2.3- Flow-sheet for production of chitin and protein hydrolysate from shrimp C.
Crangon shell waste. [Synowiecki and Al-Khateeb, 2000] ……………………………………….. 30
Figure 2.4- Chemical structures of cellulose, chitin and chitosan [Majeti and Kumer,
2000] ……………………………………………………………………………………………………………………… 31
Figure 2.5- Stru tures of (A) α- hitin and (B) β-chitin [Rinaudo, 2006] ……………………. 33
Figure 2.6- TEM micrographs of (a) CHWs in water, (b) CHWs after treatment in
Alkaline [Phongying et al., 2007] (C) TEM imaging of TEMPO-oxidized chitin
nanocrystals prepared under different conditions [Fan et al., 2008] ……………………… 37
Figure 2.7- Normalised (against matrix) properties of CHW reinforced composites at
different percentage laoding of CHW (A) Modulus, (B) tensile strength and (C) strain at
break. …………………………………………………………………………………………………………………….. 42
Figure 2.8- Water uptake at equilibrium of gly erol soy protein isolate sheet (●) and
SPI/CHW composites of SPI-5(o), SPI-10 ( ), SPI-15 (Δ), SPI- 20 (□), SPI-25 (▪) and SPI-
30 (◊) omposite onditioned at 98 RH% as a fun tion of time (A) and water uptake at
equilibrium (●) and water diffusion oeffi ient (o) as a fun tion of hitin whiskers
content for composites conditioned at 98% RH(B) [Lu et al. 2004] …………………………. 45
Figure 2.9- Variation in toluene uptake of PNRev (●), PCH5ev (o) PCH10ev ( ),
PCH15ev (Δ), and PCH20ev (□) samples as a fun tion of time at room temperature (25
°C)(A) and toluene uptake at equilibrium and toluene diffusion coefficients in
CHW/Vulcanized NR Composites immersed in toluene (B)[Nair and Dufresne, 2003A]
………………………………………………………………………………………………………………………………... 46
Figure 2.10- Formation of poly(acrylic acid) (PAA) …………….………………………………...... 47
Figure 2.11- Mechanical properties of gelatine gel reinforced PAA. Faturechi et al
[2014] (Modified) ………………………………………………………………………………………………….. 48
Figure 2.12- Tensile strength (a) and tensile strain (b) of composite hydrogels having
different graphene oxide nanosheet (GONS) content [Faghihi et al. 2014]
(Modified)………………………………………………………………………………………………………………… 49
Figure 2.13- Schematic diagram of Stokes, Rayleigh and anti-Stokes Raman scattering
of molecules. Reproduced with modification[Smith and Dent, 2005] ……………………… 51
Figure 2.14- Schematic diagram of a Renishaw Raman spectrometer, where A is a
mono hromator, B is a 40× obje tive lens and a 10 μm pinhole, C is an adjustable
mirror, D is a fixed mirror, E is a holographic notch filter, F is a 1/2 wave plate, G is an
analyser, H is a slit, I is an isosceles triangle mirror, J is a diffraction grating assembly, K
is a focusing lens, L is a charge-coupled device (CCD) detector, M is an optical
microscope, and N is a sample [Tanpichai, 2012] ………………………………………………….... 55
5
LIST OF FIGURES

Figure 2.15 Raman band shift rates with respect to strain for NaOH/urea matrix and
LiCl/DMAc solvent system and celloluse nanocomposites using tunicate (TCNWs) and
cotton (CNWs) whiskers as fillers for the peak initially located at 1095 cm-1 [Pullawan et
al. 2014] (Modified).………………………………………………………………………………………………… 59
Figure 2.16- ypi al shi s in the peak posi ons for Raman bands ini ally lo ated at
(a) 1095 cm−1 and (b) 8 95 cm−1 for all-cellulose nanocomposites produced using a
LiCl/DMAc solvent system derived matrix reinforced with 15 v/v % tunicate cellulose
nanowhiskers [Pullawan et al. 2014] ……………………………………………………………………… 60
Figure 2.17- Typical shifts in the peak position of the Raman band initially located
at 1 095 cm-1 as a function of strain for the composites of PVA and 4 wt % MFC
compared to data obtained from pure MFC networks. Solid lines are linear regressions
on the data; MFC: Gradient = -0.34 ± 0.06 cm-1 %-1, R2 = 0.99 and MFC/PVA composite:
Gradient = -0.44 ± 0.02 cm-1 %-1, R2 = 0.99. The point at which debonding is thought to
occur is indicated [Tanpichai et al., 2014] ……………………………………………………………….. 61
Figure 2.18- SEM image of the rod shape of the isolated crystal (a) and magnified
image of the square area on the crystal surface in (b) [Nishimura et al., 2008] …...... 62
Figure 2.19- Structures of polymer matrixes and soluble additives [Hosoda and Kato,
2001] ……………………………………………………………………………………………………………………… 63
Figure 2.20- SEM images of the development of the planar films into microarrays by
the subsequent overgrowth without any additives for visual determination of the
polymorphs: (a, b) calcite; (c, d) vaterite; (e, f) aragonite.[Kotachi et al.,2006] ……….. 64
Figure 2.21- Optical micrographs of calcium carbonate grown at 10 °C with 2.4 x10-3 wt
% PAA250k on 100 °C (a) and 260 °C baked (b) chitosan. Arrows indicate planar films.
Black shadows are granular particles [Kotachi et al., 2006] …………………………………….. 65

Figure 3.1- Raman peak for the silicon standard …………………………………………………….. 84
Figure3.2- Set-up to investigate the molecular orientation of chitin film and its
composites ……………………………………………………………………………………………………………. 85
Figure 3.3-Illustration of mechanical test sample of chitin, PAA films and composites 86
Figure 3.4- A 2 KN load cell customised DEBEN deformation rig used to deform chitin
film, its composites and molecular orientation of CHW within the matrix ………………. 87

Figure 4.1- Raman spectra of chitin film, 25PAA and 45PAA …………………………………….92
Figure 4.2- Raman spectra CHW/25PAA composites films at different CHW content. 94
Figure 4.3- Raman spectra CHW/45PAA composites films at different CHW content. 96
Figure 4.4- Chemical route for synthesis of CHW/PAA based composites ……………… 97
Figure 4.5-Ratio of the intensity of the band at 1698 cm-1 to the intensity of the band
at 1622 cm-1 as function of CHW content for 25PAA and 45PAA composites ………….. 98
Figure 4.6- X-ray powder diffraction of (A) chitin and (B) 25PAA …………………………......99
Figure 4.7- X-ray powder diffraction of CHW reinforced PAA composites ……………… 101
Figure 4.8- X-ray powder diffraction patterns of (A) 45PAA100 and (B) its composites
with CH ………………………………………………………………………………………………………………. 103
6
LIST OF FIGURES

Figure 4.9- Graphical presentation of (A) crystalline index and (B) particle size of 45PAA
and 25PAA composites against CHW weight …………………………………………………………. 105

Figure 5.1- Suspension of chitin whiskers prepared by acid hydrolysis …………………… 110
Figure 5.2- TEM image of CHW .…………………………………………………………………………….. 110
Figure 5.3- 3D pie chart of CHW (A) length (B) width from image analysis of TEM. 111
Figure 5.4- Typical stress-strain curves for (A) chitin film, 25PAA and (B) CHW/25PAA
composites at different loading levels of whiskers (20 mm gauge length) …………….. 112
Figure 5.5- Tensile strength for (A) chitin film, 25PAA and (B) CHW/25PAA composites
at different loading of CHW and different gauge lengths ……………………………………… 113
Figure 5.6- Strain at break for chitin film, 25PAA and CHW/25PAA composites at
different loading of CHW and different gauge lengths ………………………………………….. 114
Figure 5.7- Young’s modulus for (A) hitin film, 25PAA and (B) CH /25PAA omposites
at different loading of CHW and different gauge lengths ……………………………………. 116
Figure 5.8- Typical stress-strain curves for 45PAA and CHW/45PAA composites at
different loading levels of whiskers (20 mm gauge length) …………………………………… 117
Figure 5.9- Tensile strength for 45PAA and CHW/45PAA composites at different
loading of CHW and different gauge lengths ………………………………………………………... 118
Figure 5.10- Strain at break for chitin 45PAA and CHW/45PAA composites at different
loading of CHW and different gauge lengths ………………………………………………………… 119
Figure 5.11- Young’s modulus for 45PAA and CH /45PAA omposites at different
loading of CHW and different gauge lengths ………………………………………………………… 119
Figure 5.12- Effect of gauge length on (A) tensile strength (B) strain at break and (C)
re ipro al gauge length on Young’s modulus of hitin film, 25PAA and CHW/25PAA
composites ……………………………………………………………………………………………………………. 120
Figure 5.13- Effect of gauge length on (A) tensile strength (B) strain at break and (C)
re ipro al gauge length on Young’s modulus of 45PAA and CHW/45PAA composites
………………………………………………………………………………………………………………………………. 121
Figure 5.14- Experimentally measured tensile modulus for CHW/25PAA at different
volume fraction compared with theoretically estimations by a combination of the
Halpin-Tsai and Tsai-Pagano models ……………………………………………………………………. 124
Figure 5.15- Experimentally measured tensile modulus for CHW/45PAA at different
volume fraction compared with theoretically estimations by a combination of the
Halpin-Tsai and Tsai-Pagano models ……………………………………………………………………. 124
Figure 5.16- Free surfaces SEM images of (A) 25PAA10, (B) 25PAA30, (C) 25PAA50, (D)
free surface chitin film high magnification and (E) free surface chitin film low
magnification (F) fractured chitin …………………………………………………………………………. 126
Figure 5.17- Fractured SEM images of (A) 25PAA10, (B) 25PAA30, (C) 25PAA50, (D)
25PAA70, (E) 25PAA90 and (F)25PAA100 …………………………………………………………….. 127
Figure 5.18- Raman spectra for chitin …………………………………………………………………… 128
Figure 5.19- Raman spectra for 25PAA10, 25PAA30, 25PAA50, 25PAA70 and 25PAA90
before deformation ……………………………………………………………………………………………… 129
7
LIST OF FIGURES

Figure 5.20- Raman band located at 1622 cm−1 as a function of tensile strain for chitin
sfilm, 25PAA10, 25PAA30 and 25PAA50 composites ……………………………………………. 130
Figure 5.21- Curve shifts in the Raman spectra for a (A) chitin film, (B) 25PAA10, (C)
25PAA30 and (D) 25PAA50. Shown is the region around the Raman band located at
1622 cm-1 at 0 % strain (black) before and 1.2 or 1.4 % strain (red) after deformation
…………………………………………………………………………………………………………………………….... 131
Figure 5.22- Histogram distributions of 30 point measurements of CHW and its
composite at the Raman band initially located at 1622 cm-1. Data were collected at a
fixed spot position at different levels of tensile deformation as shown in the key… 130
Figure 5.23- Intensity of the Raman band located at 1622 cm-1 for 25PAA10 and
25PAA50 films as a function of the angle of the specimen with respect to the
polarisation axis at 0 % strain ……………………………………………………………………………… 133

Figure 6.1- TGA curves of (A) chitin and 25PAA100 and (B) CHW/PAA composites .. 142
Figure 6.2- DTGA curves of (A) chitin and 25PAA100 and (B) CHW/PAA composites. 143
Figure 6.3- TGA (A) and DTGA (B) curves of 45PAA100 ………………………………………… 145
Figure 6.4- TGA curves of CHW/45PAA composites ………………………………………………. 145
Figure 6.5- DTGA curves of CHW/45PAA composites ………………………………………….... 146
Figure 6.6- DSC heating curves of (A) chitin film and (B) 25PAA100 ……………………….. 151
Figure 6.7- DSC heating curves of 2nd scan of CHWs/25PAA composites ……………….. 151
Figure6.8- DSC heating curves of (A) 45PAA100 and (B) 2nd scan of CHW/45PAA
composites ……………………………………………………………………………………………………………. 153

Figure 7.1- Raman spectra of CaCO crystallisation: (A) in the absence of CHW and PAA
3
(b) in the presence of CHW (c) in the presence of PAA. (A=aragonite, C=calcite and V=
vaterite) ………………………………………………………………………………………………………………. 161
Figure 7.2- Raman spectra of CaCO particles synthesized at 30 °C in the presence of
3
PAA (A) 25PAA10, (B)25PAA30, and (C) 25PAA50 at different filler loading of CHW
(A=aragonite, C=Calcite and V=vaterite) ……………………………………………………………… 162
Figure 7.3- Raman spectra of CaCO particles synthesized at 30 °C in the presence of
3
PAA (A) 25PAA70 and (B) 25PAA90 at different filler loading of CHW. (A=aragonite,
C=Calcite and V=vaterite) …………………………………………………………………………………...... 164
Figure 7.4- XRD pattern of CaCO synthesized at 30 °C (A) without PAA or CHW (B) in
3
the presence of CHW and (C) in the presence of PAA (A=aragonite, C=calcite and V=
vaterite) ………………………………………………………………………………………………………………. 166
Figure 7.5- XRD pattern of CaCO synthesized at 30 °C in the presence of PAA (A)
3
25PAA10, (B)25PAA30, (C) 25PAA50, (D)25PAA70 and (E) 25PAA90 …………………….. 168
Figure 7.6- SEM images of CaCO particles synthesized at 30 °C without PAA
3
incorporation. (A) high and (b) low magnification images of rhombohedral calcite
(arrow pointing at traces of spherical vaterite) ………………………………………………….... 172
Figure 7.7- SEM images of CaCO particles synthesized at 30 °C in the presence of (A)
3
PAA (arrow pointing at spherical lumpof vaterite) and (B) CHW ……………….…………. 173
8
LIST OF FIGURES

Figure 7.8- SEM images of CaCO particles synthesized at 30 °C in the presence of PAA
3
(A) 25PAA10, (B)25PAA30, (C) 25PAA50, (D)25PAA70 and (E) 25PAA90 at different
filler loading of CHW …………………………………………………………………………………………… 174

Figure 8.1- Typical stress-strain curves for (A) chitin film, 25PAA and (B)
CHW/25PAA/CaCO composites at different loading levels of whiskers (10mm gauge
3
length) ………………………………………………………………………………………………………………….. 180
Figure 8.2- TGA curves of CHW/PAA/CaCO composites ………………………………………. 182
3
Figure 8.3- DTGA curves of CHW/PAA/CaCO composites …………………………………… 184
3
Figure 8.4- Weight loss of CHW/PAA/CaCO composites ……………………………………. 185
3
Figure 8.5- DSC heating curves of (A) chitin and (B) poly(acrylic acid) …………………. 186
Figure 8.6- DSC heating curves of CHW/PAA/CaCO composites (A) 1st scan (B) cooling
3
and (C) 2nd scan …………………………………………………………………………………………………… 187
Figure 8.7- SEM images of fracture surfaces of (A) 25PAA10Ca and (B) 25PAA30Ca 190
Figure 8.8- SEM images of fracture surfaces of (A) 25PAA50Ca, (B) 25PAA70Ca and
(C) 25PAA90Ca …………………………………………………………………………………………………….. 191

Figure 9.1- Schematic diagram of the measurement of mechanical property using AFM
cantilever [Cheng and Wang 2008] (modified) …………………………………………………… 197
9
LIST OF TABLES

Table2.1- Conditions of extraction of chitin from sea sources and extracted chitin
characteristics [Rhazi et al., 2000 modified] ……………………………………………………………. 26
Table2.2- Chitin derivatives and their proposed uses [Majeti and Kumar, 2000]
(modified) ………………………………………………………………………………………………………………. 35
Table2.3- Sizes, preparation time and temperature of CHW prepared from different
sources …………………………………………………………………………………………………………………… 38
Table2.4- Mechanical properties of CHW filled natural rubber using data obtained from
tensile tests:  ensile modulus (E), conventional rubber modulus (E ), stress at break
100%
(σ ), and elongation at break (ε ) [Nair and Dufresne, 2003A]
B B
…………………………………………………………………………………………………………………………………. 41
Table2. 5- Sorption characteristics, tensile strength and elongation, ion exchange
capacity and methanol permeability of composites [Smitha et al. 2004] (Modified)....50
Table2.6- Direction of the incident and scattered lasers relative to the reference axis
and the position of the optical components for different polarisation configurations
[Deng, 2010] (Modified) …………………………………………………………………………………………. 55
Table2.7- Raman band from Raman spectra of α-chitin, [Ehrlich et al., 2007, Gelder et
al., 2007, Bo et al., 2012] where m, mw and s are the strength of the intensity
(medium, medium weak and strong) …………………………………………………………………….. 56

Table3.1- Properties of poly(acrylic acid) as supplied by Sigma Aldrich …………………… 77
Table3.2- Properties of the chitin as supplied by Sigma Aldrich …………………………….. 77
Table3.3- Weight and volume fractions of CHW reinforced poly( acrylic acid)
composite (PAA ≈250,000) ………………………………………………………………………………….. 80
mw
Table3.4- Weight and volume fractions of CHW reinforced poly( acrylic acid)
composite (PAA ≈450,000) …………………………………………………………………………………… 80
mw
Table3.5- Weight fractions of CHW, PAA and PAA /chitin/CaCO composites
3
(PAA ≈250,000) .……………………………………………………………………………………………….... 81
mw

Table4.1- Raman bands for chitin film and poly(acrylic acid) (PAA)………………………… 93
Table4.2- Raman shift due to CHW content for 25PAA composites ……………………….. 95
Table4.3- Raman shift due to CHW content for 45PAA composites ………………………. 96
Table4.4- Values of d-spacing and Bragg diffraction angles for chitin, 25PAA and their
composites ……………………………………………………………………………………………………………. 101
Table4.5- Crystalline index (CI) and size (D) of chitin, 25PAA, 45PAA and their
composites. (Numbers in bracket are the standard deviations) …………………………….. 103
Table4.6- Values of d-spacing and Bragg diffraction angles for 45PAA and its
composites with CHW …………………………………………………………………………………………… 105

Table5.1- Summary of the extrapolated mechanical properties for chitin film, 25PAA
and 25PAA composites of the two matrices ………………………………………………………….. 122
Table5.2- Summary of the extrapolated mechanical properties for chitin film, 45PAA
and 45PAA composites of the two matrices. (Values in bracket are the standard
deviations) ……………………………………………………………………………………………………………. 122
10