- Space environmentally stable polyimides and copolyimides derived from [2,4-bis(3-aminophenoxy)phenyl] diphenylphosphine oxide
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Polyimides with a combination of properties including low solar absorptivity (α) in thin films, atomic oxygen (AO), and ultraviolet (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 (2), with aromatic dianhydrides in a polar aprotic solvent. The diamine was prepared from commercially available starting materials in a two-step reaction in relatively high yield. Copoly(amide acid)s and copolyimides were prepared using 2 in combination with other commercially available aromatic diamines. The chemistry as well as physical and mechanical properties of the polymers and films will be discussed.
- Watson, Kent A.,Palmieri, Frank L.,Connell, John W.
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- Space environmentally durable polyimides and copolyimides
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Polyimides displaying low color in thin films, atomic oxygen resistance, vacuum ultraviolet radiation resistance, solubility in organic solvents in the imide form, high glass transistion (Tg) temperatures, and high thermal stability are provided. The poly(amide acid)s, copoly(amide acid)s, polyimides and copolyimides are prepared by the reaction of stoichiometric ratios of an aromatic dianhydride with diamines which contain phenylphosphine oxide groups in polar aprotic solvents. Controlled molecular weight oligomeric (amide acid)s and imides can be prepared by offsetting the stoichiometry according to the Carothers equation using excess diamine and endcapping with aromatic anhydrides The polyimide materials can be processed into various material forms such as thin films, fibers, foams, threads, adhesive film, coatings, dry powders, and fiber coated prepreg, and uses include thin film membranes on antennas, second-surface mirrors, thermal optical coatings, and multi-layer thermal insulation (MLI) blanket materials.
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