Ice release coatings of high durability for aerospace applications

Abstract

Current in-flight aircraft anti-icing and de-icing systems rely on active methods such as heat for ice mitigation, which tends to reduce the operating efficiency of the aircraft. Significant research is currently ongoing to develop anti-icing coatings for passive ice removal from aircraft surfaces. Although significant coating advances have been achieved in reducing ice adhesion and accretion, the majority of the developed prototypes cannot survive the harsh operating environments of an aircraft. Therefore, the goal of this work was to develop a coating with significant ice adhesion reduction and of sufficiently high durability to withstand typical aerospace operating conditions (with the exception of conditions at the wing leading edge areas). Low ice adhesion topcoats and clear coats have been developed based on qualified exterior aerospace coatings, and ice adhesion tests showed a decrease of up to 95% in the ice adhesion strength as compared to control coatings. These coatings are also as durable as current polyurethane aerospace topcoats. For example, the coatings did not sustain any damage for up to 30 min in a rain erosion test conducted at typical rain impact speeds to approximate real flight conditions. In addition, ice adhesion tests performed on degraded coatings (1,700 h of QUV Accelerated Weathering Test, UVB-313 nm lamp) showed that the ice release properties were retained.