Synthesis and thermal characterization of novel poly(azomethine-urethane)s derived from azomethine containing phenol and polyphenol species

Abstract

Oligophenol-based poly(azomethine-urethane)s (PAMUs) were newly synthesized in two steps. At the first step, the prepolymers including the phenol and oligophenol based-Schiff bases were prepared by a condensation reaction of o-dianisidine with 4-hydroxybenzaldehyde/3-ethoxy-4-hydroxybenzaldehyde, and the polycondensation reactions of the corresponding Schiff bases in an aqueous alkaline media. At the second step, the PAMUs were obtained by copolymerization of the prepolymers with toluene-2,4-diisocyanate (TDI) under an argon atmosphere. The structures of the obtained compounds were confirmed by FTIR, UV-vis, 1 H NMR, and 13 C NMR, and size exclusion chromatography (SEC) techniques. The synthesized compounds were also characterized by TG-DTA and DSC analyses. Thermal decomposition steps at various temperatures were clarified by FTIR analyses of the degraded products. The physical changes to the synthesized PAMUs after exposing them to the thermal degradation steps are displayed.

Photophysical, Electrochemical, Thermal and Morphological Properties of Polyurethanes Containing Azomethine Bonding

“…In the FT-IR spectral data of Schiff bases (PDA, PDAM and PDAN), imine (-NDCH) and hydroxyl (-OH) stretch vibrations are observed in the range 1592 to 1643 and 3347 to 3366 cm ¡1 , respectively. According to FT-IR spectral data of TDI and HDI, characteristic isocyanate -CDO and -CDN stretch vibrations are observed at 2234-2250 and 1615-1584 cm ¡1 , respectively, which agrees with the literature values (20,31). According to Table 1, hydroxyl (-OH) stretch vibration of Schiff bases, -CDO and -CDN stretch vibrations of TDI and HDI disappear due to urethane formation and the new stretch vibrations appear between 3285-3380 and 1663-1747 cm ¡1 , respectively, which could be attributed to urethane -NH and carbonyl (-CDO) stretch vibrations, respectively.…”

Synthesis, characterization, and thermal degradation of new aromatic poly(azomethine-urethane)s and their polyphenol derivatives

“…The obtained PAMUs were washed by methanol (2×50 ml), acetonitrile (2×50 ml), and distilled water (2×100 ml) to remove the unreacted components. The products were dried in a vacuum oven at 75°C for 24 h (yields 91, 90, and 93% for MP-2AP,MP-3AP, and MP-4AP, respectively) [21].…”

Thermal, fluorescence, and electrochemical characteristics of novel poly(urethane-imide)s

“…According to Figure 4, urethane (-NHCO) protons of PUI-1, PUI-2, and PUI-3 are observed at 9.14, 10.04, and 6.15 ppm, respectively. [5,26] Aliphatic CH 2 O-of PUI-1, PUI-2, and PUI-3 is observed at 3.58, 3.65, and 3.65 ppm, respectively. Aliphatic -CH 3 protons of PUI-1 are observed at 2.11 ppm.…”

“…The products were dried in a vacuum oven at 75°C for 24 h (yields 85, 82, and 88% for PUI-1, PUI-2, and PUI-3, respectively). [26,27] …”