**Table 3.**

*Chemical composition of cocoa powder hulls.*

*Mechanical Properties and Chemical Stability of Bathroom Wall Composites Manufactured… DOI: http://dx.doi.org/10.5772/intechopen.102457*

**Figure 1.**

*Thermogravimetric and differential scanning calorimetry of raw cocoa powder hulls.*

Careful observation shows that from 440°C all organic matters have been degraded.

The spectrum in **Figure 1** shows four main phases of mass loss. The first mass loss of 8.00% by weight is between 40 and 100°C and has a peak around 86°C; it reflects the loss of free water contained in the cocoa shell powder. The second loss of mass corresponds to a loss of mass of 64.50% observed between 300 and 400°C, with a maximum DTG at 321°C. It is attributed to the destruction of sugars, in particular polysaccharides (hemicelluloses and cellulose) in cocoa shell powder [26]. The third loss of 22.60% observed between 321 and 401°C could reflect the degradation of the cellulose contained in the powder; in fact, cellulose would degrade at around 401°C. Between 401°C and 423°C, a loss of 5.12% is observed with a peak at around 423°C, which would be due to the destruction of lignin at 423°C, these results are consistent with those found by [26].

With regard to the physicochemical properties of these powders, we can conclude that the major compounds are cellulose, hemicellulose, and lignin, which are present in our powder, they degrade with a strong loss of mass [28]. In addition, hemicelluloses decompose at low temperature, due to their weak molecular structure. In addition to their low molecular mass, they have less regular structures in their chains [28]. The curve in **Figure 1** shows four thermal accidents. One endothermic peak is observed at low temperature around 86°C and three exothermic peaks lie between 321°C, 401°C, and 423°C. The peak around 86°C would correspond to the free water contained in the powders, and the other peaks would reflect respectively the degradation of the hemicelluloses, celluloses, and lignin of the cocoa powder hulls [28]. **Table 4** shows the different types of thermal phenomena that occur during the thermal analysis of the sample.


**Table 4.** *Types of thermal phenomena.*
