Amino acid-modified polysiloxane

The development of high-bond strength polysiloxane adhesives has faced challenges due to limitations in adhesive strength and cohesion. To address this issue, a new study introduced a biobased N-acetyl-L-cysteine (NACL) modified polysiloxane adhesive with antimicrobial properties. This adhesive exhibited enhanced bonding strength through the formation of a substantial number of hydrogen bonds. The carboxyl group in NACL underwent an acid-base neutralisation reaction with sodium ethoxide, resulting in the formation of ionic aggregates.

Inhibition against Staphylococcus aureus

These aggregates, along with hydrogen bonding, enhanced the mechanical properties of polysiloxane, leading to a further improvement in bond strength. At ambient temperature, the modified polysiloxane adhesive displayed remarkable lap shear and peel strengths, with maximum values of 8.16 MPa and 20.48 N/m for metallic iron, 3.56 MPa and 14.99 N/m for metallic aluminum, and 5.55 MPa and 20.52 N/m for metallic copper. Furthermore, the inclusion of NACL in the polysiloxane adhesive demonstrated pronounced inhibition against Staphylococcus aureus. As such, this high-performance polysiloxane adhesive has significant potential for use in the metallic bonding of medical devices, adhesive coating of metallic surfaces, and skin adhesion coating.

The study has been published in Progress in Organic Coatings, Volume 183, October 2023.