“Adhesives releasing toxins including carcinogenic formaldehyde are almost everywhere in our homes and offices,” says Jonathan Wilker, a professor of chemistry and materials engineering at Purdue University.

Purdue researchers have developed an adhesive that combines the bonding chemistry of shellfish with a corn-derived polymer.
(Photo credit: Purdue University/Jonathan Wilker)

Mussels extend hairlike fibers that attach to surfaces by using plaques of adhesive. Proteins in the glue contain the amino acid DOPA, which harbors the chemistry needed to facilitate the “cross-linking” of protein molecules, providing strength and adhesion. Purdue researchers have combined this bonding chemistry of mussel proteins with a polymer called poly(lactic acid), a bio-based polymer derived from corn.

Findings are detailed in a research paper published Jan. 4 in the journal Macromolecules. The paper was authored by Wilker and graduate students Courtney L. Jenkins and Heather M. Siebert in Purdue’s Department of Chemistry. Jenkins is now an assistant professor of chemistry at Ball State University.

“Results presented here show that a promising new adhesive system can be derived from a renewable resource, display high-strength bonding and easily degrade in a controlled fashion,” Wilker says.

The researchers tested the adhesive by measuring the force needed to pull apart metal and plastic plates that were bonded together, finding that it compared favorably with various commercial products. Unlike synthetic glues, however, the adhesive can be degraded in water.

“This new system may help lead us toward nontoxic materials sourced from nature, capable of being broken down into benign components, and enhanced recyclability of the products all around us,” Wilker says.

The research was funded by the U.S. Office of Naval Research.