Superhydrophobic polyurea coating with excellent adhesion and abrasion resistance prepared via convenient microphase separation

The alicyclic and aliphatic polyurea/siloxane block copolymer PDMS20000-PUA and PDMS3000-PUA were synthesized, respectively. And they were selected as the matrix individually and together to fabricate robust superhydrophobic coating by convenient microphase separation method. The molecules of PDMS3000-PUA formed rough spiky aggregates under strong hydrogen bond force, and its contact angle (CA) reaches 132.5 degrees. While those of PDMS20000-PUA assembled into tiny hemispheres with a diameter of 0.54 mu m, and its CA is just 114.3 degrees for low roughness. The influence of blend and solvent composition on the surface morphology was further studied. It was found that porous hierarchical structures are generated through microphase separation of partial thermodynamic compatible PDMS20000-PUA and PDMS3000-PUA. The contact angle of the coatings reaches the maximum value of 141.7 degrees in 1:1 (v/v) tetrahydrofuran/isopropanol solvent with a hydrogen bonding value of 5.95 and a solubility parameter of 10.35 x 103(Cal/m3)0.5. By further improving blade coating to spray coating, the prepared surface exhibits excellent superhydrophobicity with a contact angle of 159.6 degrees and a sliding angle of 3.1 degrees. Moreover, the coatings also possess superior adhesion and wear resistance.

Automated summary

Alicyclic and aliphatic polyurea/siloxane block copolymers were synthesized and used as matrices to fabricate robust superhydrophobic coatings through microphase separation method. The surface morphology of the coatings was influenced by the blend and solvent composition. The coatings exhibited excellent superhydrophobicity with high contact angles and low sliding angles, as well as superior adhesion and wear resistance.