| Popis: |
The characterization of polymers via analytical pyrolysis often necessitates a detailed understanding of the polymer degradation process during heating in vacuo or in an inert atmosphere. Elucidating the degradation pathways of condensation polymers with heteroatoms in their backbone chains is not an easy task, because their thermal degradation yields a number of complex polar compounds. The major pyrolysis products of these polyesters were the corresponding diols and anhydrides, such as phthalic anhydride and maleic anhydride, as well as products formed through the six-membered cyclic transition state. The relative yields of these products strongly depended on the chain length and the branching structures between neighboring ester groups in the polymer chain, as well as the degradation conditions used. Monomeric (butenoic) and oligomeric acids were observed in its pyrograms; presumably, these products are predominantly formed via the six-membered transition state. |
