Ceramers made from tantalum oxide and ductile engineering thermoplastics have potential for making X-ray absorbing, chemically resistant optical elements for space uses. To fabricate these materials, powders of general composition TaxOy(OSi(Me)3)z have been made by hydrolyzing Ta(OEt)5 with formic acid in the presence of C1Si(Me)3. These powders dissolve in alcohols with the replacements of the trimethyl siloxy group with the alkoxy moiety which may be of the group ethoxy, methoxy, and methoxy ethoxy. The soluble oligomeric tantalum oxide cluster can be mixed in any proportion with methoxyethanol solutions of phenoxy (hydroxy aryl-alkyl ether) polymer to form clear solutions which can be cast into films and subsequently powdered in liquid nitrogen. The powder with tantalum oxide weight percentages less than 60% (60 Ta-40 phenoxy) can be compression molded at 150°C into plaques that are transparent to visible light above 400 nm.
Although ultraviolet-visible (UV-Vis) spectroscopy reveals no change of the chemical resistance of the 60 Ta-40 phenoxy films was tested by exposure of N2H2—H2O for 2 hr at room temperature, there are some minor changes observed in the infrared (IR) spectrum of exposed thin films.
The 60 Ta-40 phenoxy films can be cast and compression molded into plaques which have the potential for high X-ray absorption, hydrazine resistance and good mechanical and optical properties.
KeywordsProton Nuclear Magnetic Resonance Tantalum Oxide Ethyl Formate Methoxy Ethoxy Stoichiometric Excess
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