Thermally Stable and Mechanically Strong Mesoporous Films of Poly(ether imide)-Based Triblock Copolymers

Polymer films must be thermally stable and mechanically strong to operate durably under extreme conditions (e.g., high temperature and tension). Herein we report the preparation of mesoporous films from poly(4-vinylpyridine)-block-poly(ether imide)-block-poly(4-vinylpyridine) (P4VP-b-PEI-b-P4VP) triblock copolymers. Owing to the high-performance engineering plastic PEI block, the mesoporous films are thermally stable up to 150 °C and show much higher mechanical strength than existing polystyrene-based films. Importantly, with a molecular weight of 27.7 kDa, the porous block copolymer films showed a tensile strength at break of 10.5 MPa and toughness of 0.68 MPa. The P4VP-b-PEI-b-P4VP films had predominant mesopores of tunable sizes and high specific surface areas, better than the commercial poly(ether sulfone) and polyamide films. The development of poly(ether imide)-based porous films provides an effective method for preparing thermally stable and mechanically strong membranes for extreme-condition operations.