Processing studies and thermal stability of addition polymers from 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene and Bis-dienes

1,4,5,8-Tetrahydro-1,4;5,8-diepoxyanthracene reacts with various anthracene end-capped polymide oligomers to form Diels-Alder cycloaddition copolymers. The polymers are soluble in common organic solvents, and dehydrate thermally at temperatures of 300–350°C to give thermal oxidatively stable pentiptycene units along the polymer backbone. Because of their high softening points and good thermal oxidative stability, the polymers are candidates for matrix resins for high temperature composite applications. To assess their usefulness for such applications, several parameters have been studied affecting the properties of the final polymer. These parameters include varying the formulated molecular weight of the end-capped prepolymers, and use of meta-substituted aromatic diamine in place of some of the para-substituted diamine. Processability of the resins was studied using rheometric spectrometry, and a processing scheme was devised. Finally, several formulations of neat resins were compression molded into coupons, and evaluated for longterm stability in air at 315 and 371°C. The best combination of good processability and thermal oxidative stability was obtained from polymers synthesized with small amounts of meta-diamine substitution and higher formulated molecular weight prepolymers.