The document investigates the effect of water uptake on the physical properties of amorphous inulin powder, including glass transition temperature and crystallinity. Amorphous inulin samples with varying water content were prepared and analyzed using modulated differential scanning calorimetry and wide-angle X-ray scattering. The results showed that water acts as a plasticizer at low contents but leads to crystallization at higher contents. A state diagram was proposed dividing the material behavior into glassy, intermediate rubbery, and crystalline states depending on water content.
2. INTRODUCTION
Inulin is a natural storage
carbohydrate mainly found
inplants from the Asteraceae
family. It is not a simple molecule,
but a mixture of linear oligo-
and/or polysaccharides
composed of
(2 1)-β-D-fructofuranan of
various lengths, ended by a
terminal a-D-glucopyranosyl
group
For now, commercial inulin is
mainly extracted from chicory root
and is available as a spray-dried
4. MODULATED DIFFERENTIAL SCANINGCALORIMETRY
(MDSC)
Differential scanning calorimetry (DSC) is a thermal
analysis technique which has been used for more than
two decades to measure the temperatures and heat
flows associated with transitions in materials as a
function of time and temperature .Such measurements
about physical and chemical changes that involve
endothermic or exothermic processes,or changes in
heat capacity.
5. WIDE-ANGLE X-RAY SCATTERING (WAXS)
WAXS has been used to study the structural
properties of polymer electrolytes containing silver
ions. The WAXS spectra of pure poly and poly
showed two broad amorphous peaks. The first of
these peaks was assigned to the interchain distance,
and the second peak was assigned to the distance
between the pendant groups of the polymer chains.
6. OBJECTIVE
The aim of this study was to
determine the physical changes of
theamorphous inulin powder at different water
contents. The physicalparameters investigated
were the glass transition temperature (Tg) and
the crystallinity index.
7. MATERIALS AND METHODS
Sample preparation
chicory
rootsextraction
dispersed in distilled
water at 95 0C
spray-
dried
inlet air 230 0C outlet air 120 0C.
air flow were 2l/ h and 2 barsDehydration in P2O5
( for one week )
Storage in
10. RESULTS AND DISCUSSION ( CON )
Thermal properties
Fig. 3. MDSC total heat flow using (a) non-hermetic aluminium pans of amorphous
inulin containing (1) 0.9, (2) 8.6, (3) 13.6, (4) 14.8, (5) 15.7, (6) 16.3 and (7) 18.9 g
water/
100 g dry inulin. (b) Hermetic aluminium pans of amorphous inulin containing (1) 0.9,
(2) 8.6, (3) 13.6, (4) 14.8, (5) 15.7, (6) 16.3 and (7) 16.9 g water/100 g dry inulin.
1
18.9
9
16.3
15.7
13.6
8.6
14.8
0.9
1
18.9
9
16.3
15.7
13.6
8.6
14.8
0.9
1
18.9
9
16.3
15.7
13.6
14.8
11. Fig. 4. Glass transition temperature–water content relationship (Tg–water content
state diagram). Zones I and II delimited amorphous in the glassy or rubbery state,
respectively, while zone III characterized crystallized inulin.
Thermal properties ( Con )
Powdered
Amorphous state
Sticky
still
amorphous
Crystallized
state
12. RESULTS AND DISCUSSION ( CON )
Understanding the thermal property change
Fig. 5. Temperature-Resolved Wide Angle X-ray Scattering
patterns of inulin containing 18.8 g water/100 g dry inulin. Darker
colours correspond to higher intensities.MDSC onset (145 C) and
endset (165 C) temperatures of the endothermic peaks are
represented by vertical lines.
Fig. 6. Evolution of the crystallinity index of crystallized
amorphous inulin during heating at 1.5 C min1, determined
from Temperature-Resolved WideAngle X-ray Scattering.
MDSC onset (145 C) and endset (165 C) temperature of the
endothermic peaks are represented by vertical lines.
Fig. 6. Evolution of the crystallinity index of crystallized
amorphous inulin during heating at 1.5 C min1, determined
from Temperature-Resolved WideAngle X-ray Scattering.
MDSC onset (145 C) and endset (165 C) temperature of the
endothermic peaks are represented by vertical lines.
13. CONCLUSION
The effect of water uptake during storage on amorphous
inulin properties has been investigated. Water content,
crystallinity indexes,thermal properties and glass transition
temperature evolution permitted the understanding of the
physical and behavioural changes of the amorphous material.
The Tg–water content state diagram allowed us to point out
three zones. Zone I was the plasticization effect of water on
Tg with inulin in a powdered amorphous state. The defined
zone II was an intermediate state between glassy amorphous
and crystallized inulin, with some macroscopic and thermal
property changes. In zone III, the product crystallized,
caked and no glass transition was observed. An endothermic
peakappeared at the initial glass transition, which was
attributed to themelting of inulin crystals, as confirmed by
Temperature-Resolved Wide Angle X-ray Scattering.
15. REFERENCE
Se bastien N. Ronkart , Michel Paquot , Christian
Fougnies,Claude Deroanne , Christophe S. Blecker .
Effect of water uptake on amorphous inulin properties.
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Cowie, J.M.G. , Polymers : Chemistry & Physics of Modern
Materials, 2nd. edition, Blackie Academic &
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P. S. Gill, S. R. Sauerbrunn and M. Reading. MODULATED
DIFFERENTIAL SCANNING CALORIMETRY. Journal
of Thermal Analysis, Vol. 40 (1993) 931-939
Ryoung-Joon Roe, Encyclopedia of Polymer Science and
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