MALDI-TOF, 13C NMR and FT-MIR analysis and strength characterization of glycidyl ether tannin epoxy resins

• Development of green chemistry in industry using natural polyphenols.
• The use of natural polyphenols, such as tannins in the industry.
• Preparation of bio epoxy and environmentally friendly.
• Alternative bisphenol A toxic and carcinogenic to natural polyphenols.

The chemical modification of tannin through epoxidation is a way to develop new applications for tannins and to improve tannin resins performances. In this paper the influence of reaction conditions was studied. Commercial tannin bark extract was epoxidized. The resulting products were characterized by FT-IR Spectroscopy, 13C NMR and MALDI-TOF mass spectrometry. Tannin epoxidation has been confirmed by 13C NMR and FT-MIR. Wood specimens were bonded with mixed diglycidyl ether of bisphenol A (DGEBA) and glycidyl ether tannin (GET) epoxy resin formulations. The bonded joints were tested for block shear strength. The results obtained indicated that such formulations, based on up to 75% commercial natural materials are capable of satisfying the shear strength requirements of relevant international standards.