Hard Epoxy Coating with Lasting Low Ice Adhesion Strength

A high-hardness(H) coating typically has an elevatedice adhesion strength (& tau;), while a soft coating tends to shedice easily. We recently reported a one-step process for a bilayerpolyurethane coating that achieved both high H andlow & tau;, effectively decoupling H from & tau;.However, these low & tau; values remained stable only through 12icing/deicing cycles, beyond which & tau; rapidly increased. To maintainconsistently low & tau;, another bilayer coating is prepared usinga diamine, an epoxy compound, and poly(glycidyl methacrylate) withpoly(dimethylsiloxane) (PDMS) side chains. This coating features abulk hardness of 0.31 & PLUSMN; 0.03 GPa, PDMS nanopools in the matrix,and a liquid-like PDMS brush layer on the surface. A silicone oilmixture (SOm) can be added to the formulation before coatingformation. Increasing the SOm content enlarges PDMS/SOm nanopools and surface roughness. Lubricated coatings areproduced by applying SOm or individual silicone oils (SOs)of varying viscosities to preformed nonporous and microporous coatings.This study compares ice-shedding properties of these coatings over30 icing/deicing cycles. Results show that the smooth bilayer epoxycoating, lubricated with 1.55 g/m(2) SOm, maintains & tau; values <5 kPa, 100 times lower than glass, after 30 icing/deicingcycles. This marks the first polymer coating to simultaneously exhibithigh H alongside such consistently low & tau; valuesover numerous icing/deicing cycles.

Automated summary

A high-hardness coating can resist ice adhesion, while a soft coating is prone to ice shedding. A bilayer polyurethane coating was developed that achieved both high hardness and low ice adhesion strength. Another bilayer coating with a diamine, epoxy compound, and poly(glycidyl methacrylate) with poly(dimethylsiloxane) side chains was prepared to maintain consistently low ice adhesion strength over numerous icing/deicing cycles. This study compared the ice-shedding properties of different lubricated coatings and found that the smooth bilayer epoxy coating, lubricated with a silicone oil mixture, maintained low ice adhesion strength even after 30 icing/deicing cycles.