Curing Behavior and Final Properties of Nanostructured Thermosetting Systems Modified with Epoxidized Styrene‐Butadiene Linear Diblock Copolymers

Abstract

Abstract Nanostructured thermosetting materials based on thermosetting matrices were prepared by modification of an epoxy system with linear PS‐ block ‐PB copolymers. The nanostructured thermosets were obtained through PS block segregation. Depending on the block‐copolymer content in the thermosets and its epoxidation degree, the PS domains can display micellar, worm‐like or hexagonally‐packed cylinder structures, retaining the stiffness of the epoxy matrix, where the hexagonally cylindrical morphology lead to a significant increase in fracture toughness. The rheokinetics of microphase separation during network formation was investigated. Nanostructures are judged to be formed by polymerization‐induced microphase separation, in marked contrast to equilibrium self‐organized structures that are preformed, with the microphases fixed via a curing reaction. magnified image