Robust water-wettable nanoporous polymer membranes from reactive ABC triblock terpolymers

POLY 273

Monique Roerdink, roerdink@chem.umn.edu, Liang Chen, lchen@chem.umn.edu, and Marc A. Hillmyer, hillmyer@chem.umn.edu. Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455
Chemically and mechanically robust polymer membranes were prepared using an ABC triblock terpolymer of polylactide (PLA), polydimethylacrylamide (PDMA) and a copolymer of styrene and norbornene-functionalized styrene (PN/S) as a precursor. Films cast from a mixture of the terpolymer, dicyclopentadiene (DCPD) as a curing agent, a catalyst and solvent resulted in a crosslinked material with microphase separated morphology as determined by small-angle x-ray scattering. Macrophase separation of in-situ polymerized DCPD and the terpolymer was likely thwarted through simultaneous crosslinking of DCPD with the norbornene-functionalized block of the terpolymer. Upon exposure of the resultant nanocomposite to aqueous base, a majority of the PLA phase could be removed, suggesting a bicontinuous morphology. Pores with sizes ranging from 20–40 nm were evident after PLA removal by scanning electron microscopy. Importantly the PDMA remained in the material and rendered the nanoporous membrane water-wettable. These new materials are promising as separation membranes and catalyst supports.