Polybenzoxazoles, their synthesis and thermal degradation

Thermal Rearrangement of Functionalized Polyimides: IR-Spectral, Quantum Chemical Studies, and Gas Permeability of TR Polymers

“…Thus, our spectral observations do not contradict formation of benzoxazole rings, because of thermal rearrangement. Additional evidence in favor of this structure of TR polymers has been reported in several works. , However, the intensity of these bands (1619 and 1060 cm –1 ) is insignificant in our spectra. It is interesting to note that these absorption bands are especially strong for the TR polymers of PI1 (Figure b) and the TR polymer of PI3 (see Figure b, as well as Figure S1 in the Supporting Information).…”

“…According to the literature data, the benzoxazole ring in the formed polymers should reveal the following absorption bands: 1630, 1555, and 935 cm –1 ,; 1474, 1059 cm –1 , , ; and 1617, 1058 cm –1 . Thus, PIs based on the dianhydride of 3,3′,4,4′-benzophenontetracarbonic acid and 3,3′-dihydroxy-4,4′-diaminebiphenyl should exhibit new intensive absorption bands at 1617, 1500, 1250, 1058, and 850–900 cm –1 in its IR spectrum, which are characteristic for the appearance of benzoxazole rings in the polymer structure and modification of aromatic rings due to intramolecular rearrangement .…”

Synthesis, chemistry and applications of 5-hydroxymethyl-furfural and its derivatives

“…Moreover, polyamides obtained by the condensation of the diacid 40 and benzidine derivatives 238 presented a high resistance towards temperatures up to 500 °C. [238][239][240][241] Polyamides are also utilised for the preparation of membranes showing osmotic activity 242 .…”

Metallocene-containing polyesters from reaction of 3,5-pyridinedicarboxylic acid and metallocene dihalides and their preliminary ability to inhibit cancer cell growth

“…[45] Hopff and Krieger described the synthesis of polyamides though heating of the diamine salt with the ester of PA. [46] Shizunobu and Yashiko [47] synthesized polyesters from the reaction of PA with various aromatic and aliphatic acid dichlorides employing the melt and interfacial processes. Braz and coworkers [48] prepared polyoxamides from the reaction of PA with various acid dichlorides. Hergenrother, Wrasidlo, and Levine [49] synthesized polybenzothiazoles from the condensation of aromatic bis(mercaptoamines) and aromatic dicarboxylic acids including PA.…”