Synthesis and characterization of new aromatic polyamides bearing crown ethers or their dipodal counterparts in the pendant structure. I. Benzo‐12‐crown‐4 and ortho‐bis(2‐ethoxyethoxy)benzene

Abstract

Two novel isophthalic diacid‐based monomers have been synthesized by inclusion in ring position 5 of a functionalized benzoylamine moiety. The functionalization includes a 12‐crown‐4 ether group fused with the benzene subunit and a dipodand substructure, formally a disubstitution of the benzene ring, with two sequences of ethyl‐terminated ethylene oxide units, which represent the open‐chain counterpart of the alicylic crown moiety. The polycondensation of the two diacids with five aromatic diamines yielded 10 new polyamides with crown or podand pendant substructures. The polyamides had previously been chemically characterized by NMR, IR, and elemental analysis. The polymers showed high glass transition temperatures of up to 349 °C, good thermal stability (Tdonset, N2 ≈ 400 °C), and improved solubility in organic solvents. The presence of acyclic or alicyclic oxyethylene sequences as crown ether or podand substructures and an additional amide side group per repeat unit made the polymers essentially amorphous and improved their water absorption ability in comparison with nonsubstituted polyamides. Water uptake values as high as 12% were observed at 65% relative humidity. All the polyamides showed a good film‐forming ability, and the mechanical properties of these films are considered to be satisfactory for experimental aromatic polyamides. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2270–2281, 2006

Synthesis and characterization of new aromatic polyamides bearing crown ethers and acyclic ethylene oxide units in the pendant structure. III. Benzo‐18‐crown‐6 systems and their open‐chain counterparts

“…With respect to polyamides with benzo-12-crown-4 moieties, gel formation under standard Yamazaki conditions was not observed, and instead soluble, high-molecular-weight polyamides were obtained. 4 In relation to polymers with dipodal substructures, all those derived from P8 diacid gave gels under standard Yamazaki conditions, but gel formation was observed with only one of the polymers derived from P6 and with none of the ones derived from P4.…”

“…4,5 Thus, the propensity to produce a gel increases with an increment in the oxyethylene sequences in crown or podal substructures.…”

“…In previous articles, 4,5 we reported the synthesis and characterization of new aromatic polyamides bearing benzo-12-crown-4, benzo-15-crown-15, and their dipodal counterparts as pendant substructures. In this work, we extend that study to polyamides containing pendant moieties of benzo-18-crown-6 and their dipodal counterparts.…”

“…The T g 's of polyamides derived from MPD lie between the values for PPD and DDE. 4,5,27,28 The thermal resistance, in terms of the initial decomposition temperature (T d ), was evaluated with TGA. The thermal stability under N 2 is fairly high, ranging from 390 to 415 8C for polymers derived from C6 and P8 diacid monomers (Table 2).…”

Colorimetric anion sensing by polyamide models containing urea-binding sites

“…In previous articles, we reported on the syntheses and characterisations of polymer materials with the following host units: crown ether (19)(20)(21), urea (22)(23)(24)(25) or pyrylium (13,18), along with their interaction with cations (26)(27)(28)(29)(30)(31), anions (13,18) or gas molecules (32). Herein, we report four model polyamide compounds (Scheme 1)…”