(180a) Kinetically Trapping a Triblock Terpolymer Equilibrium Network Morphology for Use As a Polymer Electrolyte Membrane

We are exploring polymer electrolyte membranes exhibiting both high modulus and conductivity by kinetically trapping a triblock terpolymer equilibrium network morphology formed from poly[isoprene-b-(norbornenylethyl styrene-s-styrene)-b-ethylene oxide] (INSO). We show that INSO self-assembles into the O⁷⁰ network morphology, an architecture in which both structural and conductive components are independently and three dimensionally continuous. The ring-opening metathesis polymerization of norbornene functionality incorporated into the styrene block is shown to kinetically trap the O⁷⁰ morphology, preventing phase transitions induced by dissolving salts in the PEO phase. Dynamic mechanical spectroscopy is used to contrast mechanical properties of both uncrosslinked and crosslinked membranes; we find kinetic trapping slows segmental relaxation in glassy styrene by ca. one decade and prevents long-time relaxation of the O⁷⁰ unit cell. Ionic conductivity through PEO in INSO membranes, as determined by impedance spectroscopy, is found to be largely unaffected by the kinetic trapping mechanism.