Castor-oil-based UV-curable hybrid coatings
Scientists have prepared a novel UV-curable hybrid coating with self-healing, recyclability, removability, and hydrophobicity.
UV-curable thermosets with self-healing and reprocessing properties – especially those derived from renewable feedstocks – are highly desired for practical applications. In a new work, repairable, recyclable, removable, and hydrophobic UV-curable polyurethane coatings derived from renewable castor oil were constructed by the employment of dynamic hindered urea bonds (HUBs). The resulting UV-curable materials not only showed high biobased contents (45.1%–47.6%), but also exhibited good thermal, mechanical, coating, and hydrophobic performance.
Enhanced performance
Furthermore, due to the rapid dissociation or exchange of HUBs and intramolecular hydrogen bonds, the resulting UV-curable coatings exhibited excellent repairability, weldability, recyclability, and removability at moderate temperatures. For instance, a selected sample demonstrated a scratch healing efficiency up to 97.0% at 140 °C for 60 min. In particular, the UV-cured sample could be physically recycled at least 4 times with enhanced performance in tensile properties, and the resulting coatings were easily removed or recycled by using low-toxicity organic solvents like ethyl acetate and dimethylformamide.
The study bas been publsihed in Progress in Organic Coatings, Volume 165, April 2022.
