Janus Nanosheets Synchronously Strengthen and Toughen Polymer Blends

Strength is usually compromised with toughness of polymer blends. We report a new way to synchronously strengthen and toughen a typical blend of epoxy resin/nitrile-butadiene rubber (EP/LNBR) with Janus nanosheets (JNs). The silica-based JNs contain a reactive epoxide group and nitrile-butadiene rubber on the opposite sides. They are robust of high strength and toughness. The JNs are covalently bound at the EP/LNBR interface upon blending and cross-linking, which can effectively transfer stress in between the two phases. At the saturation coverage of the interface with the JNs, mechanical properties of the blends reach the maxima. Excess JNs will stack into multiple layers at the interface, which will lead to interfacial slippage and thus to worse properties. This report may open a new avenue to achieve higher performance polymer materials by using Janus materials.