Curing behaviour and mechanical properties of dicarboxylated telechelic poly(epsilon-caprolactone)s/styrene-(epoxidized butadiene)-styrene triblock copolymer reactive blends

End-carboxylated telechelic poly(epsilon-caprolactone)s (XPCLs) with differ ent molecular weights were blended into a triblock copolymer of styrene-(ep oxidized butadiene)-styrene (ESBS) to investigate the curing behaviour and the mechanical properties of the XPCL/ESBS binary reactive blend. It was fo und that the time-torque cure curve showed a significant torque increase af ter a very short induction period, in which the degree of the torque increa se depended on the molecular weight of XPCL, This indicates that substantia l crosslinking reaction takes place between the XPCLs and the epoxidized po lybutadiene of the ESBS. Stress-strain curves of the blends after cure depe nded on the molecular weight of XPCL and the blend ratio. The XPCL/ESBS ble nds had sufficient thermal stability to show elastomeric behaviour at eleva ted temperature above the glass transition of the styrene domains of ESBS b ecause of formation of crosslinking points between unlike polymer component s by the reactive blending. (C) 1999 Society of Chemical Industry.