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C. Reynaud et al. International Journal of Refractory Metals Hard Materials 19(2001)425-435 The PF thermal decomposition has led to the for to the difference between the values of the ir absorptio mation of carbon dioxide, carbon monoxide, water and coefficient of each product, which furthermore varies some organic molecules containing C-H bond(alcane with the temperature, a rigorous quantitative compari for PA, monomer, dimer, etc. )in various quantities. The son between the different emitted gases cannot be per intensity of the characteristic absorption IR band of formed. Nevertheless, a semi-quantitative comparison each compound has been monitored during the thermal for each gas between the two PFA and the two atmo- related to the a mo,nt of the sas molecule however. due of the polyamide pea leads to higher amounl of 3. 3. 2. Green sample characteristics of monolithic blocks Carbon dioxide Fig. 4 indicates the influence of PFA nature and content on the bulk green density of the tape and the variation is compared to the idealised packing density of binary mixture derived by Furnas [14]. The PFA content is expressed on the basis of the ceramic volume tape ne PFa volume After thermocompaction, some residual porosity remains in the tape(16-24 vol%). However the bulk 全 green density increases with the PFA content and is higher than the bulk green density of the free PFA Eq.(1)derived by Furnas [14], where FIxture is theo- PFA bulk green density and f A is the PFa content Fig.2. Intensity of the gas IR-bands, related to I mg of PA-C, during PF PFA the thermal degradation under argon Carbon monoxide CS under O2 CS under Ar PA-C under O2 PA-C under Ar PFA and atmosphere of thermal degradation Fig. 3. Amount of gases produced during the thermal degradation(20C/min) of corn starch(CS)and PA-C under O2 or Ar gases(25 mI/min) % * 1 1 , -4 ' % + & E ' + 4, 0 , E F , , & * , 0 * ? *& , , % , * % > < 0 3 0 => $ : % 3 3 1 ;"$< % 1 J J % % '"A- $ .+ 4, 3 , % 3 % 3 9& '"+ ;"$< , 1 * 3 % 3 !77 % 3 % % 1 % 3 " " % 3 % E E* " %* " > % ' ! = + '+ %* 2 % ' = + $ 8 "+ 1 % 2 3 "3+ 4 5 67 869 ':'