Molecular composite materials formed from block copolymers containing a side-chain liquid crystalline segment and an amorphous styrene/maleic anhydride segment

Side-chain liquid crystalline block polymers containing a poly[6-[4-(4′-methoxyphenyl)phenoxy]hexyl methacrylate] (PMMA-LC) segment and a styrene-co-maleic anhydride segment (alternating structure) were prepared via reversible addition fragmentation chain transfer (RAFT) polymerization. PMMA-LC was initially prepared via RAFT polymerization mediated by 2-(2-cyanopropyl)dithiobenzoate (CPDB). The resulting polymer was subsequently isolated and used to re-initiate styrene/maleic anhydride alternating copolymerization. The block copolymerization proceeded to intermediate conversions with narrow polydispersities, however at higher conversions some molecular weight broadening was observed and this was attributed to radical-radical termination reactions. The resulting polymers were analyzed via size exclusion chromatography (SEC), differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Microporous honeycomb structured films were cast from solutions of the block copolymers to form porous molecular composites.