Bilayer nanocomposite molecular coatings from elastomeric/rigid polymers: Fabrication, morphology, and micromechanical properties

dWe fabricated bilayered nanocomposite coatings composed of a hard polymer layer placed on top of an elastomeric layer. The primary layer of poly[styr ene-b-(ethylene-co-butylene)-b-styrene] (SEBS) was attached to the surface by grafting to a chemically reactive silicon surface functionalized with ep oxy-terminated SAM. The SEES layer served as the compliant interlayer in th e bilayered polymer coating. The topmost hard layer was a high performance polymer made of epoxy resin (EP! and an amino functionalized poly(parapheny lene) (PPP). We built the bilayered structure by spincoating the EP/PPP mix ture on top of the grafted SEES layer. The solidification of the topmost la yer was initiated at low temperatures (40 - 50 degreesC) to avoid dewetting . The curing of the film was finished at 110 degreesC (15 hours) and the EP /PPP layer was strongly attached to the SEES layer. It was found that the E P/PPP layer did not penetrate inside the elastic primary layer during the s olidification The elastic response of the hard polymer layer was affected s ignificantly by the underlying elastomeric layer. The SEES layer served as a compliant interlayer capable of dissipating the interfacial stresses orig inating from dissimilarities in the physical properties between the polymer coating and the inorganic substrate.