Preparation and Evaluation of Fish Scale Collagen Protein Bioadhesive

Abstract

The widespread adoption of composite products in many developing nations has come at a significant cost to human health due to the use of toxic synthetic adhesives in their manufacturing process. The objective of this study was to produce a bio-based adhesive with biodegradable, non-toxic, and environmentally friendly properties by chemically modifying fish scale collagen protein. The whole process was divided into three steps. In the first step, fresh fish scales were washed in running distilled water for 2-3 hours to remove odor and to eliminate contaminants and minerals. In the next step, 50g of fish scale was immersed in 0.5 M NaOH solution for 24 hours at a sample/ NaOH solution ratio of 1:10 (w/v) to open the fiber bundle and remove the connecting materials. The NaOH solution was changed after 3 hours and washed in cold distilled water until a neutral pH was achieved. The scales were immersed in 0.5 M CH3COOH (acetic acid) solution for four days to prepare the solution for formulating the adhesive. Finally, after four days the solution was boiled, filtrated, and concentrated to formulate the fish scale adhesive. Solid content, FTIR, Thermogravimetric analysis (TGA), Glass Transition Temperature (GTT), gel time and viscosity of the prepared adhesives were tested and evaluated following by ASTM standards. The adhesive showed excellent appearance, viscosity, solid content 34.75%, gel time 56 seconds and 200º C in GTT. Moreover, gel time, solid content, FTIR, viscosity analysis has shown that the fish scale adhesive has the possibility to perform better that has the potentiality to replace the synthetic adhesive.