Synthesis, characterization, and properties of novel fluorine containing aromatic polyamides

Abstract

A series of novel fluorine containing aromatic polyamides were synthesized by the direct polycondensation of various fluorine containing aromatic diamines and commercially available 5-t-butyl isophthalic acid. These polyamides have good solubility in several organic solvents such as dimethylformamide, N,N-dimethylacetamide, 1-Methyl-2-pyrrolidone, dimethyl sulfoxide, and tetrahydrofuran. The synthesized polymers exhibited inherent viscosities up to 0.93 dL/g and M w up to 1,52,000 with PDI of 2.49. The polyamides exhibited good thermal stability up to 4898C for 10% weight loss in nitrogen and high glass transition temperature up to 2738C. Dynamic mechanical analysis showed a very good retention of storage modulus up to the glass transition temperature. The tan d peak value at 1 Hz was used to calculate the T g and these values are in good agreement with differential scanning calorimetry data. The polyamide films were flexible with tensile strength up to 72 MPa, elongations at break up to 14%, and modulus of elasticity up to 1.39 GPa depending on the exact repeating unit structure. X-ray diffraction measurements indicate that these polyamides are semicrystalline. Rheology study showed same trend of melt viscosity behavior with different shear rate for all polymers. Water absorption study indicates the hydrophobic nature of the polymer.

Fluorinated Poly(Arylene Ether)s

“…In relation to this, fluorinated polymers were better candidates in terms of higher permeability and permselectivity [90,[107][108][109]. The bulky hexafluoroisopropylidene group also helps increase the free volume of the polymer, thereby improving various properties of the polymers together with gas permeability.…”

Fluorinated Polyamides

“…have been incorporated in the amine structure to improve the final properties of the resultant cardo PAs [2,5,10,12,13,43]. Researchers have developed different monomers containing flexible ether linkage for the synthesis of poly(ether amide)s. Banerjee and group have synthesized different fluorinated diamine monomers containing -CF 3 group and flexible ether linkage by variation of the starting cardo bis-phenol monomers.…”

“…In continuation, Banerjee and group varied the aromatic ring between the two flexible ether linkages in the amine moiety [2,4,12,13,[44][45][46]. Therefore, the structural variations of the bis-phenol moieties that are connected to two -CF 3 -substituted biphenylene moieties through aryl ether linkages were done.…”

Fluorinated poly(arylene ether)s with aliphatic chain appended cardo moiety: Synthesis and gas transport properties

“…into the polymer main chain [16][17][18][19]. In relation to this, fluorinated polymers were proved to be better candidates in terms of higher permeability as well as permselectivity [20][21][22][23]. Besides, design of fluorine-containing polymers is of special interest because of their low dielectric constant values and significant low water absorption rates.…”