Hard but stretchable protective coating

Although foldable electronic devices have been commercially available for some time now, flexible protective coating with sufficient reliability is yet to be achieved. The integration of polyurethane acrylate and an organic-inorganic (O-I) siloxane hybrid is proposed in the present study as a promising protective coating, where both high strength and stretchability could be achieved to allow for the needed reliability for foldable electronics.

Great potential

In the work, a urethane-methacrylate siloxane hybrid (U-MSH) composite was fabricated by a physical blending of methacrylate-functionalised oligosiloxane and acrylate terminated urethane prepolymer followed by curing. The U-MSH composite demonstrates excellent performance in terms of optical (e.g., transmittance, Abbe number, UV stability) and mechanical properties (e.g., resilience under compression, tension, and scratch). These outstanding properties can be attributed to the synergetic effect of the combined polyurethane acrylate and O-I siloxane hybrid.

Excellent reliability of U-MSH coating film was successfully demonstrated using an outward-bending test, suggesting that U-MSH has great potential as a protective material for flexible electronics.

The study has been published in Progress in Organic Coatings, Volume 162, January 2022.