STABILIZATION AND MODIFICATION OF POLYCAPROAMIDE - Photochemical Reactions in Heterochain Polymers - page 46

While considering DTA curves (see Figure 1.22 and 1.23) it should be meant that thermal
decay of PCA (endotherm) occurs in inert atmosphere, whereas reaction of PCA oxidation
(exotherm) takes place together with it in the presence of air oxygen according to the
mechanism, proposed in the work [140].
Curves of mass conservation at temperature rise (Figure 1.24) show that initial PCA
(curve 4) is more stable in inert atmosphere, than in the air (curve 2). At the same time quite
another picture is observed for dyed samples. Here, the greatest effect of PCA protection is
observed at warming up in the air. So, initial PCA loses 60% of original mass at the
temperature of 400 0 C, while the dyed one - 18%. And it should be noted that PCA, dyed by
covalently linked dye, possesses higher resistance to thermooxidative destruction, than PCA,
dyed by the same dye without forming covalent bond.
Figure 1.23. DTA curves in argon, I- undyed kapron, 2- kapron dyed by active golden, yellow RCr
covalently linked 3- kapron, dyed by hydrolized golden-yellow.