Preparation, Structure And Properties Of Styrene Butadiene Rubber And Natural Rubber Super-hydrophobic Surfaces

In this paper, the super-hydrophobic surfaces were prepared with rubber as matrixmaterial. The structures and properties of SiO₂particles and super-hydrophobic rubbersurfaces before and after modification were systematically investigated by Fourier transforminfrared spectroscopy（FT-IR）, Raman spectroscopy, thermogravimetric analysis （TGA）,scanning electron microscope （SEM）, energy dispersive spectroscope （EDS）, polarizingoptical microscopy （POM）, water contact angle （WCA）, sliding angle （SA）, hydrophobicdegree, adhesion behavior, aging resistance, acid and alkali resistance and mechanicalproperties and so on.Firstly, the super-hydrophobic SBR-SiO₂coatings were prepared by dip coating，inwhich the precipitated silica was modified with hydroxyl silicone oil （HSO）, and SBR wasreasonably cross-linked with dicumyl peroxide （DCP） before costing. The results show thatthe coating has good appearance without any cracks and water contact angle of the coatingreaches157.0°when HSO/SiO₂mass ratio is1:1, SiO₂content is70phr, DCP content is5phr,the cross-linking temperature is155℃, and the cross-linking time is20min. Thesuper-hydrophobic coatings have good hot air aging resistance, ultraviolet （UV） agingresistance, acid resistance and abrasion resistance, but the alkali resistance ofsuper-hydrophobic coatings is poor.Secondly, the nature rubber super-hydrophobic surfaces were prepared by etchingaluminium template method and gas grafting method. The results show that the water contactangle of the NR surface reaches153.9°and its sliding angle is less than7°when HCl solutionmass concentration is9%, etching time is12min¹6min, ultrasonic treating time is10min,grafting temperature is90℃, grafting time is24h. EDS analysis shows that NRsuper-hydrophobic surfaces contain Si and Si-CH₃. The NR surface has poor acid and alkaliresistance, hot air aging resistance and UV aging resistance.Thirdly, the super-hydrophobic surfaces were prepared by solid phase grafting ofH-Si69-SiO₂particles on NR surface in the process of NR hot pressing molding. Theorthogonal experiment shows that the hydrophobic degree of H-Si69-SiO₂particles ismaximum and up to32.81%when reaction temperature is110℃, reaction time is24h, modifier amount is1.8, and its weight ratio is3:2. TGA shows the HSO and Si-69comprehensive weight grafting rate reaches2.15%. The water contact angle of NRsuper-hydrophobic surface reaches152.1°, and sliding angle is3°⁷°, and trapped aircontent is87.3%in Cassie model. The super-hydrophobic NR surface has poor acid and alkaliresistance, hot air aging resistance, UV aging resistance and poor mechanical properties.In the end, FT-IR or Raman spectra analysis shows that the modified silica particles andNR super hydrophobic surface has Si-CH₃. SEM analysis shows that the three kinds ofsuper-hydrophobic surfaces have micro-nano hierarchical rough structure. The micro-nanohierarchical rough structure in combination with the low surface energy of Si-CH₃rendergood super-hydrophobic properties of the rubber surfaces.