Synthesis and Characterization of Perfluoroalkyl Heterocyclic Elastomers
Final technical rept. 1 Sep 1968-1 Sep 1969
DOW CHEMICAL CO MIDLAND MI
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Perfluoro-4,9,14,19-tetraoxadocosane diimidate-dihydroxybenzidine polymers have been prepared from carefully purified monomers. DTA measurements show the glass transition temperature is -15C. and the onset of thermal decomposition occurs at 350 - 400C. in nitrogen. The highest intrinsic viscosity attained was 0.28. Polymers prepared from dihydroxybenzidine and methyl perfluoro-4,9-dioxadodecanediimidate soften at about 65C. with a Tg near 21C. Thermal decomposition takes place above 400C., and intrinsic viscosities to 0.38 have been attained. A new polymer has been prepared from the reaction of 3,3-diamino-4,4-dihydroxybenzophenone with methyl perfluorosebacimidate. The polymer softens at 205C., forms films and has excellent thermal stability. Whereas the reactions with dihydroxybenzidine are heterogeneous, this polymerization reaction is completely homogeneous since the polymer and both monomers are soluble in hexafluoroisopropanol. The intrinsic viscosity of the initial polymer was 0.23.
- Organic Chemistry