1. No category

Synthesis and Characterization of Novel Cellulosics
Problem statement
Petroleum based polymeric materials
• Limited existing quantities of fossil supplies • Escalating cost • Problem of non biodegradability of petroleum based polymers • The recent environment conservative regulations. Th
t
i
t
ti
l ti
Natural polymers
 Renewable Renewable
Environment friendly
Contain many functional groups suitable to chemical
functionalization
Cost effective 2
Background
Cellulose is the most abundant renewable biopolymer. Over ~1010 tons are produced per year and only 3% are explored.
and only 3% are explored.
‐ Linear homopolymer of D‐anhydroglucopyranose
u ts co ected by β( ) g ycos d c
units connected by β(1‐4) glycosidic linkages ages
Cellulose source
DP
Cellulose
‐ Semicrystalline in nature
‐ High degree of polymerization (DP)
Cotton
Wood
Pulp
Valonia
Rayon
Bagasse
Acetobacter xylinum
8000-15000
8000-9000
500-2100
25000-27000
300
700-900
2000-6000
3
Cellulose
Cellulose exists in four different polymorphs I (Iα, Iβ), II, III, IV
∆
∆
Hydrogen bonds of
cellulose I
cellulose II
S. Kamel et al. Polymer Letters, 2008, 2, 758–778
M. De Souza Lima et al.. Macromolecular Rapid Communication, 2004, 25, 771‐787 4
Cellulose I and II particle types Particle Type
Particle size Length (μm) Width(nm) Crystallinity (%) Wood fiber &
Plant fiber
>2000 20‐50
43‐65
Microcrystalline cellulose
10‐50 10‐50(μm)
80‐85
Mi fib il t d
Microfibrilated
0 5 10’
0.5‐10’s 10‐100
10 100
45 58
45‐58
Nanofibrilated Cellulose
0.5‐2 4‐20
51‐69
Cellulose nanocrystals
0.05‐0.5 3‐8
54‐88
Algae cellulose
>1 20‐30
>80
Bacterial cellulose
>1 6‐50 65‐79
Cellulose II
Regenerated cellulose
g
27‐43
R. J. Moon, A. Martini, J. Nairn, J. Simonsen and J. Youngblood, Chem. Soc. Rev., 2011, 40, 3941–3994
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Applications of cellulose fiber derivatives
Cellulose esters
Films, fibers, explosives
coatings heat
coatings, heat resistant fabrics
Cellulose ethers Food additives, fibers, coatings, oil‐well drilling, g,
g,
gelling and foaming , paints, detergents, cosmetics controlled‐
cosmetics, controlled
release drug tablets
Oxidized cellulose
Wound dressing, pharmaceutical
pharmaceutical, skin care
S. Kalia et al. (eds.), Cellulose Fibers: Bio‐ and Nano‐Polymer Composites, Springer‐Verlag Berlin Heidelberg 2011
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Cellulose beads
Important features of bead cellulose
Cellulose fiber solution
•Excellent
Excellent mechanical stability mechanical stability
•Rigid spherical particles
•Narrow particle size distribution
•High chemical resistance and compatibility with
•High chemical resistance and compatibility with most commonly used solvents •High temperature stability •High selectivity of separation
•High selectivity of separation
Regeneration
Bead cellulose
Bead cellulose
Application of bead cellulose
 Metal adsorption
 Immobilization support
 Chromatography
 Drug delivery D. Zhoua, L. Zhanga and S. Guo, Water Res. 39, 3755 (2005). W. De Oliveira and W. Glasser, J. Appl. Polym. Sci. 60, 63 (1996).
V. Weber, I. Linsberger, M. Ettenauer, F. Loth, M. Höyhtyä and D. Falkenhagen, Biomacromolecules 6, 1864 (2005)
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Cellulose nanowhiskers (CNWs)
Cellulose nanowhiskers are defined as crystalline rod‐like nanoparticles which are obtained by acid hydrolysis of
nanoparticles which are obtained by acid hydrolysis of cellulose fibers
Plant cell
Microfibril
200nm
G. Siqueira, J. Bras, A. Dufresne, Biomacromolecules 2009, 10, 425‐432. M. A. S. Azizi Samir, F. Alloin, A. Dufresne, Biomacromolecules 2005, 6, 612‐626. S. Beck‐Candanedo, M. Roman, D. G. Gray, Biomacromolecules 2005, 6, 1048‐
1054. M. M. de Souza Lima, R. Borsali, Macromol. Rapid Commun. 2004, 25, 771‐787.
Acid
hydrolysis
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Cellulose nanowhiskers (CNWs)
Acid Hydrolysis
OH
H2SO4 /HCl
O
HO
O
OH
OH
OH
O
HO
O
OH
OH
HO
HO
O
OH
HO
O
OH
O
OH
H2SO4
Chracteristics of CNWs
Nano dimension
d
High aspect ratio
g
High surface area
High mechanical property
Y. Li, A. Ragauskas, Advance in diverse applications of nanocomposites 2011, pp.17‐36.
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Cellulose nanowhiskers
The geometric dimensions depend on the source of the cellulosic
material and hydrolysis conditions.
Cotton
Ramie
Wood
L/D=11.8
L/D=28.6
L/D=25.0
Tunicate
L/D=67.0
Dimensions:
Length: 100 – 1000 nm; Diameter: 4 – 50 nm. Habibi, Y.; Goffin, A.‐L.; Schiltz, N.; Duquesne, E.; Dubois, P.; Dufresne, A. J. Mater. Chem. 2008, 18, 5002. Azizi Samir, M. A. S.; Alloin, F.; Paillet, M.; Dufresne, A. Macromolecules 2004, 37, 4313. Roohani, M.; Habibi, Y.; Belgacem, N. M.; Ebrahim, G.; Karimi, A. N.; Dufresne, A. Eur. Polym. J. 2008, 44, 2489.Favier, V.; Canova, G. R.; Cavaille, J. Y.; Chanzy, H.; Dufresne, A.; Gauthier, C. Polym. AdV. Technol. 1995, 6, 351.
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Effect of reaction parameters on cellulose nanowhiskers properties
Effect of reaction conditions on whisker properties (H2SO4 hydrolysis, softwood pulp)
Reaction conditions
diti
(reaction time (min), acid/pulp)
Length (nm)
Aspect ratio
ti
Sulfur content(%)
Surface charge d it ( / 2)
density (e/nm
25, 8.75
141±6
28.2
0.89±0.06
0.33±0.02
45, 8.75
120±5
24.5
1.06±0.02
0.38±0.01
45 17 5
45, 17.5
105±4
23 3
23.3
1 26±0 01
1.26±0.01
Sample
Amounts of acidic groups on
Amounts of acidic groups on surface (mmol kg‐1)
Strong acid groups
Weak acid groups
H2SO4
84
26
HCl
0
<18
TEM images of (a) H
TEM images of (a) H2SO4 4 (b) HCl hydrolyzed whiskers
(b) HCl hydrolyzed whiskers
J. Araki et. al. Colloids Surfaces A, 1998, 142, 75 – 82. J. Araki et. al. J. wood Sci. 1999, 45, 258 ‐ 261
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Cellulose nanowhiskers potential areas of application
Nanocomposites
p
Packaging, Adhesive
Electronic displays Foams
Electronic displays, Foams
Aerogels, Films
Paper & Paperboard p
p
Coatings / barriers
Biomedical
Bioimaging nanodevice drug
nanodevice, drug delivery technology, skin care
Arboranano* is a new Canadian Forest NanoProducts
Network whose objective is to develop high value products from
nanocrystalline cellulose.
*Canada’s Business‐led Networks of Centers of Excellence program, FPInnovations
*C
d ’ B i
l dN t
k fC t
f E ll
FPI
ti
and NanoQuébec. 12
Typical chemical modification of cellulose
Substitution
Oxidation
Acid hydrolysis
Oxidative cleavage of C2‐C3 glycol
l l
Substitution
Oxidation
Mild reaction
Highly selective
Highly selective
Cellulose
Dialdehyde cellulose
Dialdehyde
cellulose
(DAC)
DAC acts as a reactive
intermediate
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Research Studies
To investigate and explore the versatility of cellulose, a renewable resource of raw materials using periodate oxidative
renewable resource of raw materials using periodate oxidative fragmentation synthetic approach
Chemical modification of cellulose through periodate oxidation
Cellulose fibers
Cellulose beads
Cellulose nanowhiskers
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