Addition curing thermosets endcapped with 4‐amino [2.2] paracyclophane

A new family of addition curing polyimides were prepared that contained 4-amino (2.2)-paracyclophane as the endcap. An improved synthesis of the endcap 4-amino-(2.2) cyclophane was accomplished increasing the yield to 60 percent and simplifying the procedure. DSC and rheological analysis of endcapped polyimide oligomers confirmed that the onset for polymerization of the ethylene bridge was 250 C. C-13 CP/MAS NMR was used to determine the structural changes of the oligomers after thermal treatment. The cyclophane capped polyimides were successfully compression molded to form void free neat resin specimens. Tg's as high as 353 C were obtained by thermomechanical analysis for postcured samples. Preliminary thermal stability studies suggest that these resins have a high onset of decomposition ranging from 549 to 567 C. 16 refs.