This paper presents a new process for obtaining eco-epoxide adhesives synthesized from bio-renewable raw material (tannic acid—TA) and used for bonding lightweight materials (aluminum (Al) and carbon fiber reinforced polymer (CFRP)). Two synthesized bio-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA, were used as a replacement for the toxic epoxy component based on Bisphenol A. The effect of eco-epoxy components on the interface adhesion was measured by the determination of adhesion parameter b, which was compared to the reference epoxy (REF). The increase of adhesion parameter b was 77.5% for A and 151.5% for B. The adhesion of both eco-adhesives was tested using the bell peel test (BPT) with the Al and CFRP adherends. When compared to REF, the average peel load for B was 17.6% (39.3%) and 58.3% (176.9%) higher for the Al and CFRP adherends, respectively. Complete adhesion failure of REF reflected the weak adhesion to both Al and CFRP, which was improved by the addition of eco-epoxy components A and B showing the presence of cohesive failure. The microhardness testing method of interface adhesion was proven to be a fast and reliable testing method, providing a qualitative indication in adhesive selection.

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).