New polytriazoleimides containing green synthesized titanium dioxide using Artemisia pallens plant extract: optical, dielectric, thermal and mechanical properties

Abstract

A novel aromatic diamine containing a pyridine pendant group, 1,2,3-triazole ring and ether linkage was synthesized by ‘click reaction’ in the presence of Cu(I) catalyst. Titanium dioxide (TiO₂) was introduced in poly(amic acid) to prepare poly(triazole-imide) (PTAI) nanocomposite film by typical solution casting and thermal imidization method. The TiO₂ was prepared from Artemisia pallens plant extract by sol–gel method. The structure of the PTAI was confirmed by FT-IR and NMR analyses. The morphologies of TiO₂ and PTAI as well as those of PTAI/TiO₂ nanocomposites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. PTAI/TiO₂ nanocomposite films containing different amounts of TiO₂ (0–15 wt%) were compared in terms of their morphologies and thermal, mechanical and optical properties. The tensile strength and elongation at break decreased with an increase in the TiO₂ percentage. Furthermore, the incorporation of TiO₂ in the polymer matrix significantly improved the glass transition temperature (260–283 °C) and thermal stability (T_5% were found to be in the range of 483–540 °C) of the composite films in terms of their char yield (found to be in the range of 49.3–60.1 at 800 °C). The dielectric constant (in the range of 3.12–4.10 at 1 MHz) and dielectric loss (in the range of 0.15–0.30 at 1 MHz) increased with an increase in the content of TiO₂. This effective approach shows a potential application in fabricating multifunctional polymer-based composites.