Regioselective synthesis of polygamma (γ) acid

Abstract

The oxidative polymerization of 6-amino-4-hydroxy-2-naphthalenesulfonic acid in an aqueous alkaline medium leads to the formation of a polygamma (g) acid consisting of regioselective 1-4 oxazine rings.Spectral characterizations were performed by NMR, FT-IR, and UV-Vis techniques. The average molecular weight and polydispersity index of the gamma acid polymer (g-AP) were found to be 32 000 Da and 1.42, respectively. g-AP also presented an uncommon multicolored emission behavior in dimethylsulfoxide (DMSO). When excited at 405, 480, and 532 nm, g-AP emitted blue, green and yellow light, respectively. X-ray diffraction (XRD), differential scanning calorimetry (DSC), dynamic mechanical analyses (DMA), and transmission electron microscopy (TEM) illustrated that g-AP is composed of semicrystalline nanofiber structures with different lengths between 10-500 nm. The kinetic parameters related to the solid state thermal decomposition of g-AP were determined using differential isoconversional methods (Friedman and Kissenger) and integral isoconversional methods (FWO, KAS, Tang, Starink and Bosewell). By using the Tang, KAS, FWO, Starink, Bosewell, Kissenger and Friedman methods, the average values of the activation energies were calculated to be 184.4, 184.4, 185.4, 188.5, 183.6, 179.7 and 187.1 kJ mol À1 , respectively. The master plot curves also suggested a diffusion-type kinetic model for the solid state thermal decomposition stage of g-AP.

Biological Activity and Optical Sensor Properties of Green Synthesis Polymer

“…The ipso carbon of the NH2 group was assigned at 132.02 ppm, and the −C−N−C− peak of the bonding at 143.42 ppm. The peak of C−C bonding formed by the dispersion of radicals in the ring was observed at 142.74 ppm [27–29] . Other carbon signals related to polymerization are also seen in Figure 3.…”

“…The ChemistrySelect peak of CÀ C bonding formed by the dispersion of radicals in the ring was observed at 142.74 ppm. [27][28][29] Other carbon signals related to polymerization are also seen in Figure 3. Due to the proton elimination of the carbons at the points where the monomer units are attached to each other, the peak intensity decreases and as a result of the bonding, new peaks belonging to the carbons with different chemical environments are seen.…”

“…The observation of 1384 cm À 1 CÀ N stretching vibration and 1102 cm À 1 CÀ OÀ C stretching vibration confirms this. [27][28][29] ChemistrySelect 1…”

Synthesis route to regioselectively functionalized bifunctional polyarene

“…Finally, structural characterizations confirm the suggested structure of the resulting nanoparticles. The SO 3 H proton signals of monomer and polymer are observed at 9.86 and 9.03 ppm, respectively …”

“…The -SO 3 H proton signals of monomer and polymer are observed at 9.86 and 9.03 ppm, respectively. 25 SEM observations were used to investigate the surface morphological properties and particle size of PANSA. SEM images of PANSA in powder form are shown in Fig.…”