LAUSR

Abstract A series of ladder-like silsesquioxane and their compositional gradient hybrid coatings with epoxy were fabricated by solution-diffuse technique, which involved pre-curing of epoxy followed by coating the silsesquioxane/tetrahydrofuran solution and then post-curing. The resulting material combined the advantages of the two components. The corresponding synergetic effects of the composite coating were evaluated by various coating characteristics, such as adhesion strength, hardness, thermal stability, flame retardancy, hydrophobicity, optical transparency and chemical resistance. The semi-interpenetrating polymer network structure can avoid serious phase separation at the interface between silicon and epoxy layer, and the gradient interface structure was proved by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Moreover, the influences of various ladder-like silsesquioxane and commercial linear polysiloxane on the performance of the ultimate coating were analyzed. Compared with the composite coating used linear polysiloxane, those containing ladder-like silsesquioxane behave significantly higher thermal stability, adhesion properties and chemical resistance. It is believed that the simple preparation method and excellent properties may promote large-scale application of the latter in the field of high-performance coatings.