Synthesis and characterization of epoxy resin coating with improved fire resistance by the addition of modified tannic acid

The paper presents a new process for obtaining eco-epoxide materials with reduced combustibility or completely non-combustible, which are synthesized from bio-renewable raw materials, whose production process consists of two stages. A particular aspect of multiple environmental significance is the use of bio-renewable resources and the reduction of the share of the toxic epoxy component in the production of epoxy materials. The first stage considers the synthesis epoxy resin components: epoxy functionalized tannic acid (TA) – ETA, and synthesis of phosphate derivatives of TA - glycidyl ester of TA modified by phosphoric acid (PGET). The second stage considers the synthesis of bio-epoxy resins using ETA and PGET that are used as a replacement of the epoxy resin component (A) – bisphenol A based epoxy in a ratio 25-100% as a reactive diluent to obtain products that can be used in the construction and other industrial fields and have reduced combustibility or completely non-combustible. The second part presents the results of thermal and mechanical tests for some of the obtained derivatives. The addition of 25% of TA derivate improved the toughness as well as the tensile strength of epoxy material. Thermogravimetry showed that samples containing tannin epoxide showed more residue left. Partial or full replacement of the epoxy component with a tannin component produces eco-friendly material with while significantly increased fire resistance (V-2 to V-0).