Modified epoxy resin with SEBS-g-MAH to fabricate crack-free and robust hydrophobic coatings on the surface of PP/SEBS matrix

Epoxy resin (EP) has been widely used in superhydrophobic coating areas for excellent adhesion and robustness. However, large amounts of hydrophobic particles addition are required to make the polar EP coating presents hydrophobicity, which will simultaneously cause the epoxy resin to crack. In this work, suitable SiO₂ content was analyzed to pursuit the superhydrophobicity of epoxy resin coatings. Then, functionalized polyolefin elastomer maleic anhydride grafted styrene-ethylene/butylene-styrene (SEBS-g-MAH) was adopted to modify the cracking properties of the epoxy coatings. Results indicate that the coating with 50 wt% SiO₂ content can present Cassie's superhydrophobic state and the water contact angle reached 155^o, while the coating exists cracking performance significantly. Effects of SEBS-g-MAH on the surface performance of EP coatings were then investigated. EP/SEBS-g-MAH (5/5) coating can hardly find the cracks and the water contact angle still possesses 143^o, which means that SEBS-g-MAH can improve the interface interaction between EP and SiO₂ particles and modify the cracking behavior. Hence, the robust superhydrophobic coating by combining EP, SEBS-g-MAH and superhydrophobic SiO₂ particles was successfully fabricated on the surface of polypropylene (PP) / styrene-ethylene-butylene-styrene copolymer (SEBS) matrix.