All the copolymers were amorphous and show no crystalline DSC endotherm on repeated heating and cooling cycles. Table shows glass transition values for the ST-ICAA copolymers prepared in this work with no correlation to the size and position of the ICAA ring substitution apparently due to non-uniform composition, monomer unit distribution, and/or molecular weight and MWD. A single Tg was observed for all the copolymers with values 84-154ºC. Information on thermal stability of the copolymers (Table ) was obtained from thermogravimetric analysis (Table ). Decomposition of the copolymers in nitrogen occurred in two steps, first in the 247-500ºC range with residue (2-11% wt), which then decomposed in the 500-800ºC range. The decomposition products were not analyzed in this study, and the mechanism has yet to be investigated.