Effect of the Physicochemical Properties of Starch Adhesives on the Mechanical Properties of Composites from Cellulosic Materials Doped with Rust

Abstract

The study examined the potential use of starch obtained from cassava and yam sources for the production of stable industrial adhesives that can be utilized in the production of composites. Cassava and yam tubers used in the study were obtained from Mowe and Ile-Ife (both in southwestern Nigeria) and washed free of sand and impurities before sun-drying. Starch and protein were then extracted from the cassava and yam tubers. The results indicated that both cassava and yam starches were suitable for this purpose. However, the particle size of the starch granules was found to be an important factor in determining the physicochemical properties of the adhesive. Composites produced with cassava starch adhesive were found to be more resistant to moisture than those produced with yam starch. Additionally, cassava adhesive was able to utilize more lignocellulosic fibers while still maintaining stability, provided that its limit was not exceeded. Furthermore, the addition of 2% metal additive (Fe3+ ions) improved the properties of the composites through coordination. Cassava starch-based composites were found to exhibit higher crystallinity than those produced with yam starch. The adhesive produced from these starch samples was found to be competitive with formaldehyde-based resins, with the added advantage of being non-toxic and capable of neutralizing the protons of acids with their excessive hydroxyl groups. Overall, the use of these cellulosic materials in the production of composites presents an environmentally friendly solution to the problem of waste and pollution. The study findings suggest that the starting materials are inexpensive, widely available, and environmentally friendly, and that they can produce products of greater economic importance.