Dynamic probe of the interface in lamellar forming non-linear block copolymers of the (BA)₃B and (BA)₃B(AB)₃ type. A dielectric spectroscopy study

Dielectric spectroscopy is employed in lamellar forming non-linear block copolymers of the type (BA)₃B and (BA)₃B(AB)₃ based on polyisoprene (A) and polystyrene (B), at temperatures well below the order-to-disorder transition temperature and below the glass transition temperature of the hard phase (polystyrene). We show here that dielectric spectroscopy can be used as a tool to probe the interface in ordered block copolymers with a basic triblock unit. Our estimate of the interfacial width is based on the mobility of the junction points at the interface and compares favorably with the estimated thickness from thermodynamics.