3.7. Thermogravimetric analysis
The thermogravimetric curves of MCC, TCSt, pure PNAI, and PNAI/TCSt composite were illustrated in Fig. 4. Where MCC lost about 90 % of its original weight by increasing the temperature up to 300°C due to the decomposition of cellulose, TCSt lost about 45% of its weight at 199-252 oC this was in agreement with Freire et al. and Jandura et al. reports [41, 44], who explained the early decomposition of fatty acyl cellulose with long chain substitution (C11-C18) by the decrease in the degree of crystallinity of esterified cellulose. Then, TCSt lost about 25% at temperature range 255-350 and 460 oC due to the pyrolysis of the esterified and the non-esterified parts of cellulose. Furthermore, pure PANI shows three major stages for thermal weight loss, the initial stage of weight loss occurred at 74oC and PANI lost about 10 % of its original weight due to the evaporation of moisture. The second stage took place at temperature range 230–330 oC with a slight weight loss due to the loss of HCl dopant [45]. Finally, the last stage of weight loss occurred at 425–556 oC due to the decomposition of PANI molecules, this thermal degradation behavior was similar to the reported PANI degradation curve [21]. The degradation isotherm of TCSt/PNAI composite at (50%) composition exhibited a slight weight loss by 9 % at 67 0C …show more content…
This peak has a very low intensity reflecting the hydrophobic nature of the matrix. The linear relation between sig' (the real part of conductivity function) and the frequency at lower temperatures as shown in the inset of the figure in addition to the low dielectric loss values assure the perfect insulating feature of the matrix. The inset indicated that the conductivity tends to be in the order of femto Siemens per centimeter at 0.1
The thermogravimetric curves of MCC, TCSt, pure PNAI, and PNAI/TCSt composite were illustrated in Fig. 4. Where MCC lost about 90 % of its original weight by increasing the temperature up to 300°C due to the decomposition of cellulose, TCSt lost about 45% of its weight at 199-252 oC this was in agreement with Freire et al. and Jandura et al. reports [41, 44], who explained the early decomposition of fatty acyl cellulose with long chain substitution (C11-C18) by the decrease in the degree of crystallinity of esterified cellulose. Then, TCSt lost about 25% at temperature range 255-350 and 460 oC due to the pyrolysis of the esterified and the non-esterified parts of cellulose. Furthermore, pure PANI shows three major stages for thermal weight loss, the initial stage of weight loss occurred at 74oC and PANI lost about 10 % of its original weight due to the evaporation of moisture. The second stage took place at temperature range 230–330 oC with a slight weight loss due to the loss of HCl dopant [45]. Finally, the last stage of weight loss occurred at 425–556 oC due to the decomposition of PANI molecules, this thermal degradation behavior was similar to the reported PANI degradation curve [21]. The degradation isotherm of TCSt/PNAI composite at (50%) composition exhibited a slight weight loss by 9 % at 67 0C …show more content…
This peak has a very low intensity reflecting the hydrophobic nature of the matrix. The linear relation between sig' (the real part of conductivity function) and the frequency at lower temperatures as shown in the inset of the figure in addition to the low dielectric loss values assure the perfect insulating feature of the matrix. The inset indicated that the conductivity tends to be in the order of femto Siemens per centimeter at 0.1