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Phase transition
behavior of NaCMC, PLys and CMC-PLys
complex films in the presence of various amounts of water is measured by a DSC.
Cooling and heating rates are 10 oC/min, sample weight of 3-5 mg in a sealed type aluminum vessel. For the measurement of
samples containing sorbed water, a small amount of pure water is added using a
microsyringe. The water content (Wc, g/g) is calculated by the following
equation 1 20.

 

Water content,Wc (g/g) = mass of sorbed water/ mass of dry sample                                          (1)

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Rachtanapun
P et al. (2011) Synthesize and characterize carboxymethyl cellulose powder obtained
from Mimosa pigra. The effects of various NaOH concentrations on the degree of substitution, viscosity and thermal
of carboxymethyl cellulose are also investigated. Thermal properties are studied using DSC. The results obtained
revealed that the melting point of the samples decreases as the percentage of NaOH
is increased 21.

Effect of various NaOH concentrations on
thermal properties of CMC powder

The effects
of various NaOH concentrations on the thermal property of cellulose from Mimosa
pigra peel and CMCm powder are determined by differential scanning calorimetry.
The melting temperature (Tm) of cellulose (Mimosa pigra pulp) is 107.3 oC, and CMCm synthesized with 30, 40, 50, and 60% NaOH was 114.5, 106.7,
98.3, and 98.1 oC, respectively. The melting temperature of carboxymethyl
cellulose obtained from mimosa (CMCm) slightly decreases as the level of NaOH
increased. While the %NaOH in the alkalization reaction increases, the
substitution of carboxymethyl group also increases.
The change in melting temperature results from the interference with
crystallinity is caused by the presence
of random irregularities produce by the somewhat bulky side groups from carboxymethyl
group 21.

Akram M.
et al. (2016) identify the thermal behavior
of plain CMC and to characterize the resulting by-products resulting from
pyrolysis processes. The pyrolytic behavior
of the plain CMC at low temperature ranges between 260 and 300 oC.
By preliminary experiments conducted using differential scanning calorimetry to
define the temperature range necessary for the process. Results of DSC under
temperature ramp-up conditions present in
Figure 3 shows an endothermic peak indicating the loss of water content in
the range of 45-160 oC. Further, two overlapping exothermic peaks
are depicted at 284 and 304 oC revealing the splitting off of various
functional groups along with the decomposition of the cellulose chain and its
subsequent carbonization. The first exothermic peak coincides with the
decomposition process while the second is caused by the breaking down of the
decomposition products (acetic acid and various volatile organic matters) 22.

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