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Fig. 35: Reaction order as a function of temperature .......................................................... 121
Fig. 36: Frequency factor as a function of temperature....................................................... 121
Fig. 37: Activation energy as a function of temperature ...................................................... 122
Fig. 38: A simple graphical representation of appearance of TGA/DTA charts
obtained by pyrolysis of EVA................................................................................................. 125
Fig. 39: Mass loss rates as a function of time for different types of EVA. These results
are extrapolated from the model for all types of EVA.......................................................... 127
Fig. 40: Relative mass loss curves (EVA + EVA*) represented in function of time
and defined (parameterised) by VA percentage.................................................................... 132
Fig. 41: On the same model as the preceding curves, this one represents the mass loss
for the single EVA (the first stage)......................................................................................... 123
Fig. 42: Points corresponding to the table of calculations of VA percentage in order
to visualise errors in function of EVA type considered for modelling ................................ 133
Fig. 43: Relative errors as a function of VA percentage....................................................... 134
Fig. 44: CEA personnel in the middle of manipulating plutonium with plastic gloves ...... 135
Fig. 45: Representation of mass in time for EVA/PS mixture (25/75 ratio) for the heating
rate of 10 °C.min -1 . N.B.: Experimental mass is in green, theoretical in blue..................... 145
Fig. 46: Representation of mass variations in time for EVA/PS mixture (25/75 ratio)
at the heating rate of 10 °C.min -1 ............................................................................................ 146
Fig. 47: Superposition of TGA curves for pure EVA, pure PVC, and the mixture of both,
at three different ratios (X-Y %, where X stands for EVA, and Y stands for PVC) .......... 153
Fig. 48: Kinetic scheme of EVA degradation......................................................................... 156
Fig. 49: Mathematical expression of the kinetic model of EVA pyrolysis ........................... 156
Fig. 50: Comparison of experimental and calculated curves for pure PVC ....................... 157
Fig. 51: Kinetic scheme of PVC degradation......................................................................... 157
Fig. 52: Kinetic model of PVC expressed mathematically.................................................... 158
Fig. 53: Broido-Schafizadeh reaction scheme ....................................................................... 158
Fig. 54: Comparison of the experimental and calculated curve for the pure cellulose
pyrolysis................................................................................................................................... 160
Fig. 55: Comparison of experimental and calculated curve for EVA/PVC mixture .......... 161
Fig. 56: Comparison of experimental and calculated curves for EVA/Cellulose mixture
pyrolysis................................................................................................................................... 163
Fig. 57: Superposition of TGA experimental curves of pure cellulose, pure EVA
and of the mixture of both...................................................................................................... 164
Fig. 58: Gram-Schmidt of pure EVA ..................................................................................... 169
Fig. 59: Absorption spectrum during the EVA degradation at 1,006.87 s .......................... 170
Fig. 60: Characteristic spectrum of acetic acid..................................................................... 170
Fig. 61: Absorption spectrum during the degradation of EVA at 1,579.19 s...................... 171
Fig. 62: Gram-Schmidt of the pure PVC ............................................................................... 172
Fig. 63: Characteristic transmitance spectrum (= 1 - absorbance) of HCl ........................ 172
Fig. 64: Absorption spectrum during the PVC degradation at 922.6 s ............................... 173
Fig. 65 : Gram-Schmidt of EVA/PVC mixture...................................................................... 174
Fig. 66: Absorption spectrum during the degradation of the EVA/PVC mixture
at 785.23 s ................................................................................................................................ 174
Fig. 67: Absorption spectrum for the degradation of EVA/PVC mixture at 785.23 s........ 175
Appendix C
Fig. C-1: Thermogravimetric unit TGA 92............................................................................ 203
Fig. C-2: Microbalance B92.................................................................................................... 204
Fig. C-3: Furnace..................................................................................................................... 205
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