Diglycidyl Ether of Bis-phenol-A, Epoxy Resin and Triphenylamine Linked Azomethine-Based Polymer Networks as Thermally Resistant, Blue Light Emissive Smart Materials

A series of novel epoxy : phenol polymer thermosets (P1–P3) are synthesized from the reaction of phenol containing triphenylamine (TPA)-azomethine and epoxy resin, diglycidyl ether of bisphenol A with n = 0.03. TPA linked azomethine-based phenol were synthesized by the acid catalyzed reaction of aromatic/aliphatic amine and 4,4'-diformyl triphenylamine. Which were characterized by elemental, Fourier transform infrared (FT-IR) and ¹H NMR spectral analysis. The thermosetting polymers were characterized via FT-IR spectral analysis. The incorporation of TPA moiety in connection with azomethine linkage improved the processability of the resulting polymers, therefore, synthesized polymers are soluble in a variety of common organic solvents. Thermal features of P1–P3 were evaluated via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Aromatic TPA moiety in the thermosetting network has enhanced their thermal stability (upto 370°C) as compared to conventional epoxy : phenol thermosets. The photophysical properties of the thermosetting polymers were determined via UV-visible absorption and photoluminescence (PL) emission spectral analysis in NMP (10 μM) as well as in solid state. All the polymers were optically transparent and exhibit excellent blue light emission in the range 435–460 nm with PL quantum efficiency in the range 1.5–7.7. The mechanical stability of all the polymers was evaluated by tensile strength measurement. The above-mentioned characteristics indicate that the synthesized thermosetting polymers display appreciable thermal stability, efficient blue light emission and appreciable processability as well as good mechanical strength, which can be potential candidates as light emissive coatings and adhesives.