Sulfonated copoly(norbornene)s bearing sultone pendant groups and application as proton exchange membranes candidates

Novel copolynorbornenes bearing pendant sultone groups (designated as P(BN/SulNBOH) and P(BN/SulNBOMe)) have been successfully synthesized via copolymerization of functionalized norbornenes bearing sultones (designated as SulNBOH and SulNBOMe) with 2-butoxymethylene norbornene (BN). The catalyst system showed high catalyst activity (10 4 g polymer /mol Ni ·h) and the obtained copolymers have high molecular weight and a narrow molecular weight distribution. Furthermore, the achieved copolymers P(BN/SulNBOH) and P(BN/SulNBOMe) were converted into sulfonated copolymers sP(BN/NBOH) and sP(BN/NBOMe). Both sP(BN/NBOH) and sP(BN/NBOMe) membranes displayed low water uptake, high thermal properties, good mechanical properties, and better proton exchange membranes properties. The proton conductivities measured in the hydrated state at 80 °C ranged from 10 −5 to 7.19 × 10 −3  S·cm −1 . Novel copolynorbornenes bearing pendant sultone groups are synthesized. The achieved copolymers are converted into the sulfonated copolymers. The proton conductivities of the membranes measured in the hydrated state at 80 °C ranged from 10 −5 to 7.19 × 10 -3  S·cm −1 .