Formation of Icephobic Surface with Micron-Scaled Hydrophobic Heterogeneity on Polyurethane Aerospace Coating

Development
of an anti-icing surface on a desired industrial coating patch/object
has been the persistent challenge to several industries, such as aviation
and wind power. For this aim, performing surface modification to implement
the icephobic property on existing commercial coatings is important
for practical applications. This work accomplishes an icephobic coating
overlying a PPG aerospace polyurethane coating. It manifests a clear
capability to delay the formation of frost as well as to reduce the
adhesion strength of ice. This icephobic coating is sustained by a
unique hydrophobic heterogeneity in the micron-scale of segregation,
which is realized through solution casting of a specific copolymer
consisting of random rigid and soft segments, namely poly­(methyl methacrylate)
and poly­(lauryl methacrylate-2-hydroxy-3-(1-amino dodecyl)­propyl methacrylate),
respectively. A wrinkled pattern developed over the coating is observed
because of the diverse traits between these two segments. Besides,
the OH/NH groups of the soft segment are crosslinked by a diisocyanate
monomer upon drying and curing to strengthen the coating. More importantly,
integration of a small dose of paraffin wax into the copolymer induces
a spread of soft microdomains on the winkled pattern surface. It is
hypothesized that these dual heterogeneous assemblies are responsible
for the icephobicity since they instigate distinct interactions with
condensed water droplets. Lastly, the thermoelectric cooling (Peltier
effect) and the adhesion strength of ice on the typical coatings were
assessed. This investigation also includes examination on the icephobic
durability of coating, which is enhanced when a small amount of polyethylene
oligomer is incorporated into the coating.