Self-healing anti-icing coatings prepared from PDMS polyurea

Abstract

With the help of double hydrogen bonds between urea groups, a self-healing anti-icing coating was prepared from polydimethylsiloxane (PDMS)-based polyurea (PDMSPU) that was synthesized from bis(3-aminopropyl)-terminated PDMS and 2,4-toluene diisocyanate. Furthermore, by incorporating a lubricant of inert silicone oil and the cross-linking agent of 1,3,5-tris-(4-aminophenoxy)benzene (TAPOB), the anti-icing coatings exhibited elastic, slippery and durable properties. The wettability, ice shear strength, abrasion-resistance, mechanical and self-healing properties of the prepared anti-icing coatings were systematically investigated. Results showed that the ice shear strength of the PDMSPU anti-icing coating with 150 wt% silicone oil was 7.9±2.9 kPa, significantly lower than that of pristine PDMSPU (74.7±7.2 kPa). The additional introduction of 2 wt% TAPOB could effectively counteract the adverse effect of the lubricant so that the tensile strength (∼1 MPa) of the coating could be comparable to pristine PDMSPU (855±96 kPa). The PDMSPU coating containing 150 wt% silicone oil and 2 wt% TAPOB could maintain the ice shear strength below 50 kPa against 10 icing/deicing cycles and at 12.0±3.3 kPa after 5000 abrasion cycles, and exhibit self-healing properties after treating at 60°C for 10 or 15 h. The slippery self-healing PDMSPU anti-icing coatings could be suitable for anti-icing surfaces in low temperature environments.