Space environmentally stable polyimides and copolyimides derived from 2,4-bis(3-aminophenoxy) phenyl-diphenylphosphine

摘要

Polyimides with a combination of properties including low color in thin films, atomic oxygen (AO), and ultra-violet (UV) radiation resistance, solubility in organic solvents in the imide form, high glass transition (Tg) temperatures and high thermal stability have been prepared and characterized. The polymers were prepared by reacting a novel aromatic diamine, [2,4-bis(3-aminophenoxy)phenyl]-diphenylphosphine oxide (3-APPO), with aromatic dianhydrides in a polar aprotic solvent. The diamine was prepared from commercially available starting materials in a two-step reaction in high yields. Thin films prepared by solution casting of polyimide solutions exhibited very low color and high optical transparency (～80%) as determined by UV/visible spectroscopy. The polymers exhibited T{sub}gs ＞ 200 °C depending upon the structure of the dianhydride. A series of copoly(amide acid)s and copolyimides was prepared using 3-APPO in combination with other aromatic diamines. Based on the chemical structure of these materials it is anticipated that they will have good AO and UV resistance. They are potentially useful in a variety of applications on spacecraft such as thin film membranes on antennas, second-surface mirrors, thermal/optical coatings and multi-layer thermal insulation (MLI) blanket materials. The chemistry, physical and mechanical properties of the polymers will be discussed.