Zirconium pendent poly(amic acid) and polyimide based on 3,4'-ODA and ODPA

Abstract

Aromatic polyimides long been attractive for applications in the aerospace and electronic industries. But many polyimide materials are readily oxidized by atomic oxygen (AO) in low earth orbit (LEO) because neutral atomic oxygen (AO) is the most predominant species. Polysiloxane-polyimide polymer blend, manufactured by Dupont as a back up material for the International Space Station (ISS) solar array design, is very durable in ground-based plasma ash testing. However this silicon containing material was observed to produce volatile contaminants, which form and escape via cracks in the coating when tested on the Long-Duration Exposure Facility, which was 69 months in LEO. In 1993, Dr. Illingsworth found that a Zr complex produced no volatile intermediates upon ground-based plasma AO exposure. In addition, zirconium complexes were thought to have all other properties required for atomic oxygen resistance (AOR) materials: ZrO sub 2 is one of the most stable metal oxides; a ZrO sub 2 protective layer should formed if the initial protective layer is compromised, i.e., a 'self-healing' property similar to that of Si-AOR film should be exhibited; Zr is relatively abundant. In this study, we synthesized and characterized a high AO durable polymer by binding Zr (adsp)(dsp) complex to the polymer chain.