Considerable
effort has been expended in the study of the thermal
decomposition of cellulosic materials, to explain the order of reaction and
also to estimate the activation energy and the rate of decomposition. Various
investigations of cellulose pyrolysis include isothermal studies and dynamic
thermogravimetric analysis in different oxidizing and inert atmospheres by many
researchers 17.

Thermal analysis and kinetic study

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Hydration has a significant influence on the
physical properties of carbohydrates that reflect on its direct applications
as, cosmetics,
anti-freezing properties in food or protective film abilities. Several
mechanisms have been proposed for moisture absorption by carbohydrates. Douglas
de Britto et al. (2009) study degree of humidity, non-isothermal and isothermal
degradation of CMC. The degree of humidity determines
in triplicate assays by heating the sample up to 150 oC and holding
the isotherm for 20 min. Before the analysis,
the samples were conditioned in a chamber with 100% degree of humidity for 1
week. For the non-isothermal experiments,
the samples heated from room temperature to 500 oC at a heating rate
varying from 2.5 to 15.0 oC min?1. For the isothermal experiments, the samples heated at a rate of 10
oC min?1 to 150 oC, maintained at this
temperature for 10 min and then equilibrated to the desired temperature for 80
min. He also studies the total sorbed
water measured by TG analysis. The degree of humidity found for cellulose in a
100% relative humidity ambient was 13.6±1.0, which is very close to that
reported for cotton and amorphous cellulose.

The gases generated by the pyrolysis of
cellulose consist mainly of H2, CO2, CO, CH4,
C2H6, C2H4, trace amounts of larger
gaseous organics and water vapor. This is an extremely complex process,
generally undergoing a series of reactions. The simplest feature of this
process is the DTG peak temperature, corresponding to the maximum reaction
rate, Tm, and the weight loss value. The TG curves for cellulose and
some CMC, salts scanned at heating rate ?=10 oC min?1 over
the range 100–500 oC, in nitrogen atmosphere 18.

x

Hi!
I'm Homer!

Would you like to get a custom essay? How about receiving a customized one?

Check it out