Synthesis, characterization, thermal and electrochemical properties of poly (phenoxy-imine)s containing benzothiazole unit

• Published in: Polymer bulletin (Berlin, Germany) Germany), 2024-06, Vol.81 (8), p.7231-7254
• Main Authors: Kaya, İsmet, Dinçer, Emin, Yağmur, Hatice Karaer
• Format: Article
• Language: English
• Subjects: Aminobenzothiazoles; Aqueous solutions; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Electrochemical analysis; Energy gap; Ethanol; Gel chromatography; Glass transition temperature; Heat resistance; Hydrogen peroxide; Imines; Molecular weight; NMR; Nuclear magnetic resonance; Organic Chemistry; Original Paper; Oxidizing agents; Physical Chemistry; Polymer Sciences; Polymerization; Polymers; Protons; Sodium hypochlorite; Soft and Granular Matter; Surface properties; Thermal resistance; Thermodynamic properties
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/s00289-023-05062-3

In this study, Schiff bases (SCH-1 and SCH-2) were synthesized from the condensation reaction of 2-aminobenzothiazole with 3-hydroxy-4-methoxybenzaldehyde and 3-hydroxy-4-ethoxybenzaldehyde. Poly(phenoxy-imine)s were synthesized from Schiff bases via oxidative polycondensation by NaOCl (6–14% aqueous solution) as oxidant in alkaline medium and H 2 O 2 (35% aqueous solution) as oxidant in THF medium. The structures characterizations of Schiff bases and poly(phenoxy-imine)s were confirmed by FT-IR, 1 H and 13 C NMR, CV, UV–Vis and TGA analyses. Limit oxygen index (LOI) and the heat resistance index ( T HRI ) temperature were determined from thermogravimetric measurements of compounds. P-SCH-2-A showed the highest LOI as 45.50 with self-extinguishing according to other polymers (18–30). The optical band gap of P-SCH-2-A was determined to be 1.99 eV. Additionally, the optical band gap energy of compounds were calculated by using the Tauc method. According to the Tauc method, the optical band gap ( E g ) value of P-SCH-2-A was calculated to be 2.20 eV. The glass transition temperatures ( T g ) and surface properties of poly(phenoxy-imine)s were determined from DSC and SEM analyses, respectively. The weight average molecular weight ( M w) values of P-SCH-1-O, P-SCH-2-O, P-SCH-1-A and P-SCH-2-A were calculated to be 7400, 8400, 3100 and 19,100 g mol −1 from gel permeation chromatography (GPC) measurements. Graphical abstract