Degradation weight loss

Film Titration, HPLC, gravimetric analysis, SEM, ESCA Hydrolysis, degradation, weight loss, changes in surface morphology [91, 102]... 

Fig. 11. Logarithm of heating time compared with temperature to attain various degrees of degradation of wood (35). No parentheses indicates weight loss on oven heating a single parenthesis indicates modulus of mpture on oven heating and double parentheses indicates weight loss on heating beneath...

NMR studies15 1 1 on polymers prepared with, 3C-labeled BPO have shown that the primary benzoyloxy and phenyl end groups formed by tail addition to monomer are thermally stable under conditions where the polymer degrades. They persist to > 50% weight loss at 300°C under nitrogen. Thus, these groups are unlikely to be directly responsible for the poor thermal stability of PS prepared with BPO as initiator. On the other hand, the secondary benzoate end groups, formed by head addition or transfer to initiator, appear extremely labile under these conditions. Their half life at 300°C is <5 min. 

Onset Onset Onset Weight Loss in the Major Degradation Steps (%) Peak Maximum Temperatures (T ad rC) Rate of Decomposition (div/df) at (%/min) Char Residue at 600°C... 

The second phase of polymer degradation is characterized by a decrease in the rate of chain scission (Fig. 19) and the onset of weight loss. Weight loss has been attributed to (1) the increased probability that chain scission of a low molecular weight polymer will produce a fragment small enough to diffuse out of the polymer bulk and (2) the breakup of the polymer mass to produce smaller particles with an increased probability of phagocytosis. The decrease in the rate of chain scission, as well as the increased brittleness of the polymer, is the result of an increase in the crystallinity of PCL,... 

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