The non-oxidative thermal degradation of poly(di- n-alkyl itaconates). II. Analysis of the polymer residue

The residues remaining after the thermal degradation of poly(di- n-alkyl itaconates) with ester substituents ranging from methyl to n-octyl were studied. It was found that the thermal stability of the polymers decreased with increasing size of the alkyl group. Depolymerisation was the main degradation pathway with the depolymerisation zip length being very small and independent of the alkyl substituent. The number of bonds broken per monomer unit, s/ P 0, increased with increasing temperature and time of degradation, as well as with increasing size of the alkyl substituent. The threshold temperature of degradation of each polymer was calculated from the values of s/ P 0. At lower degradation temperatures and times branching occurs in PDBI and PDHI and crosslinking in PDOI.