Starch-Based Adhesive
A starch-based adhesive is an adhesive whose primary raw material is starch, which can be extracted from natural sources like corn, potato, and wheat. These adhesives can range from simple starch and water blends to more complex formulations modified with acids (dextrin adhesives) or alkalis (jelly gums), or enhanced with additional modifying ingredients or synthetic polymers.
Starch-based adhesives consist of two main components: amylose and amylopectin. They are widely regarded for their availability, low cost, renewability, and biodegradability, making them a promising natural adhesive option. The adhesive properties of starch stem from its numerous glycosidic bonds and hydroxyl groups, which provide inherent stickiness.
Despite their advantages, traditional starch-based adhesives have some limitations, such as poor water resistance, low bonding strength, and susceptibility to mildew. These limitations are primarily due to the abundance of hydroxyl groups in starch. However, through modification and formulation enhancements, these adhesives can be used effectively in various applications, including as a formaldehyde-free alternative in the wood industry and in packaging.