Novel Ferrocene-Based Organometallic Poly(ether sulfone amide imide)s: Preparation, Characterization, and Properties

A new ferrocene-based diamine (ESAFDA) with built-in ether, sulfone, and amide groups was prepared via reaction of two synthetic precursors. Firstly, 1,1′-ferrocenedicarbonyl chloride was prepared from 1,1′-ferrocenedicarboxylic acid using oxalyl chloride. In another reaction, nucleophilic substitution reaction of 3-aminophenol with bis(4-chlorophenyl sulfone) was used for synthesis of 3,3′-(4,4′-sulfonyl bis(1,4-phenylene) bis (oxy)) dianiline (SBOD). Finally, the diamine was prepared via nucleophilic reaction of SBOD with 1,1′-ferrocenedicarbonyl chloride. The precursors and the diamine were characterized by conventional methods and the diamine was used for preparation of different ferrocene-based poly(ether sulfone amide imide)s through polycondensation with three different dianhydrides. The polymers were characterized by elemental analysis, FTIR and ¹H-NMR spectroscopy. Various properties of the polymers including inherent viscosity, molecular weight, solubility, thermal stability and behavior, flame-retardant nature, mechanical properties, and crystallinity were studied. Presence of ferrocene structure in companion to ether, sulfone, and amide units in the backbone of polyimides led to improved solubility of the polymers in polar aprotic solvents and enhanced thermal stability and flame-retardant character of polyimides.