Environmental benign synthesis of low-viscous triethanolamine based hyper- branched epoxy thermoset

Abstract

A room temperature curable, low viscosity hyper-branched (HPBs) epoxy resin has been synthesised by a single step A2 + B3 polycondensation reaction which would be a good proposition from an industrial point of view. An attempt has been made to obtain industrially suitable hyperbranched epoxy thermosets which exhibit high thermostability, high tensile strength and elongation at break (i.e. high toughness), where an aromatic (Bisphenol A, A2) and aliphatic (Triethanolamine, B3) moiety is combined in the hyperbranched structure of the resin with an aliphatic poly (amido-amine) as a hardener. The prepared resin show surprisingly low viscosity when the ratio of Bisphenol A: Epichlorohydrine (ECH) is maintained at a ratio of 1:3 i.e. a high amount of ECH is added and the remaining ECH is washed off by azeotropic distillation process. Prepared HPBs resins have been studied using 1H NMR, 13C NMR, IR, and TGA analysis. The hyperbranched epoxy resin with 20 wt% triethanolamine (TELA) show high performance and might be utilized in advanced thin film application.