Novel Asymmetric Aromatic Polyimide Having Excellent Space Environmental Stability and Application for Solar Sail “IKAROS” Membrane

Abstract

Structure–property relations for isomeric aromatic polyimides containing asymmetric aromatic imide structures have been discussed. Asymmetric polyimide 2,3,3’,4’-oxyphthalic dianhydride(a-ODPA) with 4,4’-oxydianiline(4,4’-ODA) exhibited higher Tgs than those of symmetric s-ODPA/4,4’ODA. Furthermore, the polyimide indicated a large drop in the storage modulus, E’ beyond the Tg. Based on these results, novel asymmetric polyimide (ISAS-TPI) was developed for heat sealable polyimide film with high stability in space. This paper also presents an application of the thin ISAS-TPI film: the world’s first solar sail membrane, used for “IKAROS”