Molecular Tailoring of Fluorocarbon Ether Bibenzoxazole Polymers to Lower Glass Transition Temperatures
Technical rept. Jun 1973-Sep 1974
AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH
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The synthesis of fluorocarbon ether biso-aminophenol monomers was accomplished by a multistep route from long-chain fluorocarbon ether diiodides and the reaction conditions optimized. Polycyclocondensation of these monomers with novel, long-chain fluorocarbon ether diimidate esters led to linear fluorocarbon ether bibenzoxazole FEB polymers soluble in hexafluoroisopropanol and Freon 113. Polymer structures were verified by elemental and infrared analysis. Some of the Feb polymers were obtained in moderate to high molecular weights with inherent viscosities in the range of 0.4 to 0.5 dlg. High fluorocarbon ether content gave the desired low glass transition temperatures without significant sacrifices in thermooxidative stabilities. Rubbery polymers with glass transition temperatures as low as -58C -72F were obtained. With respect to thermooxidative stability, onset of weight loss of the FEB polymers during thermogravimetric analysis in an air atmosphere occurred in the 350-400 C 660-750 F range.
- Polymer Chemistry