Development of a novel adhesive composed of all-natural components

Recent synthetic adhesives can release toxic fumes, such as formaldehyde, which is a serious problem. Thus, there is an urgent need for a non-toxic adhesive for assembling furniture and for other uses indoors and in close proximity to people. Therefore, the aim of this study was to develop a non-toxic glue based on all-natural ingredients. First, we considered mixtures of plant-derived tannins and animal-derived gelatin or ovalbumin. Some compositions demonstrated a high capacity for long-term storage and strong gluing properties. However, none of them were water-resistant. Therefore, we replaced the gelatin with poly-l-lysine to improve the glues' water-resistance. In further tests, these mixtures passed the Euronorm EN314 class 1 standard. Thus, we have developed a two-component adhesive (tannin and ε-poly-l-lysine) which is both harmless and environmentally friendly.