Synthesis and Properties of Novel Fluorinated Polyamides Based on Noncoplanar Sulfoxide Containing Aromatic Bis(ether amine)

Abstract

A novel sulfoxide containing bis(ether amine) monomer, 2,2′-sulfoxide-bis[4-methyl(2-trifluoromethyl)4-aminophenoxy) phenyl ether] (M2), was synthesized from the halogen displacement of 2-chloro-5-nitrobenzotrifluoride with dibenzosulfoxide (DH) in the presence of potassium carbonate, followed by catalytic reduction of bis(ether nitro) intermediate with Zinc/Ammonium chloride. A series of organic-soluble poly(ether amide)s (PA1–7) bearing sulfoxide and electronwithdrawing trifluoromethyl group were synthesized from bis(ether amine) with various aromatic diacids (1–7) via a direct polycondensation with triphenyl phosphite and pyridine. The resulting polymers had inherent viscosities ranging from 0.35 to 0.90 dL g−1 at a concentration of 0.5 g/dL in N,N-dimethylacetamide (DMAc) solvent at 25 °C. All the polymers showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents (e.g., N-methyl-2-pyrrolidone (NMP), DMAc, and N,N-dimethylformamide) and even dissolved in less polar solvents (e.g., pyridine, and tetrahydrofuran). Also these polymers could be cast into flexible and tough films from DMAc solutions. The glass-transition temperatures of these poly(sulfoxide ether amide)s were recorded between 160–220 °C. 10% weight loss temperatures were recorded in the range of 400–505 °C in nitrogen and 380–480 °C in air atmosphere.