Durable icephobic surfaces
Durable icephobic materials form anti-ice coatings on a variety of substrates, including for aircraft, powerlines, vehicles, marine structures, communications towers, outdoor equipment, and the like. The icephobic may comprise an elastomeric polymer with a low crosslink density (e.g., ≤1,300 mol/m3) and low initial ice adhesion strength (e.g., τ ice ≤100 kPa prior to exposure to icing conditions). Further, the icephobic material maintains τ ice after 10 icing/deicing cycles that is ≥50% of the initial τ ice Introducing optional miscible liquids enhances interfacial slippage of chains in the elastomeric polymer. The low τ ice levels minimize ice buildup and eliminate necessary work to remove any accumulated ice via passive removal during normal operation. Other icephobic materials include linear polymers with plasticizers distributed therein or PDMS-silane coatings, both of which are free of any layers of surface liquids. Methods of making such icephobic materials are also provided.
1. A durable icephobic material comprising an elastomeric polymer defining an exposed surface and having a crosslink density of less than or equal to about 200 mol/m 3 , wherein the elastomeric polymer comprises one or more polymers selected from the group consisting of: a urethane-based polymer, polydimethylsiloxane (PDMS), and combinations thereof, and an exposed surface of the elastomeric polymer exhibits an initial ice adhesion strength of less than or equal to about 50 kPa prior to exposure to icing conditions and an ice adhesion strength after 10 cycles of icing and deicing conditions that is less than or equal to about 50% above the initial ice adhesion strength and the exposed surface of the elastomeric polymer is free of any layers of liquid.
2. The durable icephobic material of claim 1 , wherein the elastomeric polymer comprises the urethane-based polymer and is hydrophilic.
3. The durable icephobic material of claim 1 , wherein the elastomeric polymer comprises the urethane-based polymer formed from a first precursor selected from the group consisting of: toluene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, and combinations thereof, a second precursor comprising a polyol, and a third precursor selected from the group consisting of: di(ethyl)toluenediamine, di(methylthio)toluene diamine, and combinations thereof.
4. The durable icephobic material of claim 1 , wherein after 5,000 abrasion testing cycles, the ice adhesion strength remains less than or equal to about 50 kPa.
5. The durable icephobic material of claim 1 , wherein after acid/base exposure, corrosion testing, and peel testing, the ice adhesion strength remains less than or equal to about 50 kPa.
6. The durable icephobic material of claim 1 , further comprising a liquid miscible with and distributed within the elastomeric polymer that enables interfacial slippage, wherein the exposed surface of the elastomeric polymer is free of any layers of the liquid formed thereon.
7. The durable icephobic material of claim 6 , wherein the liquid is selected from the group consisting of: polydimethylsiloxane (PDMS) oil, polymethylphenylsiloxane (PMPS) oil, perfluoroether oils, natural oils, synthetic oils, and combinations thereof.
8. The durable icephobic material of claim 1 , wherein the crosslink density is less than or equal to about 50 mol/m 3 .
9. The durable icephobic material of claim 1 , wherein the initial ice adhesion strength is less than or equal to about 25 kPa.
10. The durable icephobic material of claim 1 having a thickness of greater than or equal to about 100 μm to less than or equal to about 1,000 μm.
11. The durable icephobic material of claim 1 , wherein the elastomeric polymer comprises the urethane-based polymer transparent to electromagnetic radiation in a visible light spectrum.
12. The durable icephobic material of claim 1 , wherein the elastomeric polymer comprises polydimethylsiloxane (PDMS) formed from a two-part PDMS siloxane precursor having a first part comprising tetra(trimethylsiloxy)silane, dimethylvinylated and trimethylated silica, and dimethylvinyl-terminated dimethylsiloxane and a second part comprising dimethyl, methylhydrogen siloxane, dimethylvinyl-terminated dimethylsiloxane, tetramethyl tetravinyl cyclotetrasiloxane, and dimethylvinylated and trimethylated silica.
13. The durable icephobic material of claim 1 , wherein the elastomeric polymer comprises polydimethylsiloxane (PDMS) formed from a PDMS-silane having two terminal chlorine functional groups and is represented by a structure:
where n ranges from 0 to 51.
14. The durable icephobic material of claim 13 , wherein the PDMS-silane is selected from the group consisting of: 1,3 dichlorotetramethyldisiloxane, 1,5 dichlorohexamethyltrisiloxane, 1,7-dichlorooctamethyltetrasiloxane, chlorine-terminated polydimethyl siloxane where n=3-6, chlorine-terminated polydimethyl siloxane where n=24-51, and combinations thereof.
15. A durable icephobic article comprising:
an exposed surface of the article comprising an elastomeric polymer having a crosslink density of less than or equal to about 1,300 mol/m 3 , wherein the elastomeric polymer comprises one or more polymers selected from the group consisting of: a urethane-based polymer, polydimethylsiloxane (PDMS), and combinations thereof, and an exposed surface of the elastomeric polymer exhibits an initial ice adhesion strength of less than or equal to about 100 kPa prior to exposure to icing conditions and an ice adhesion strength after 10 cycles of icing and deicing conditions that is less than or equal to about 50% above the initial ice adhesion strength and the exposed surface is free of any layers of free liquid formed thereon.
16. The durable icephobic article of claim 15 , wherein the durable icephobic article is a component in an aircraft, a vehicle, a marine vessel, outdoor equipment, snow or ice removal equipment, recreational equipment, a wind turbine, telecommunications equipment, power lines, and combinations thereof.
17. The durable icephobic article of claim 15 , wherein the exposed surface of the durable icephobic article comprising the elastomeric polymer is capable of preventing ice from forming thereon for at least 100 cycles of icing and deicing.
18. The durable icephobic article of claim 15 , further comprising a liquid miscible with and distributed within the elastomeric polymer to enable interfacial slippage, wherein the exposed surface is free of any layers of the liquid formed thereon.
19. The durable icephobic article of claim 18 , wherein the liquid has a melting point of less than or equal to about 32° F. (0° C.) and a viscosity of greater than or equal to about 5 cP to greater than or equal to about 10,000 cP at 40° C.
20. The durable icephobic article of claim 15 , wherein the ice adhesion strength after 10 cycles of icing and deicing is less than or equal to about 25 kPa.