A series of polyacrylonitirle-b-polystyrene (PAN-b-PSt) block copolymers was synthesized via initiators for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) and the morphologies of these polymers in thin film were studied. Appropriate ICAR ATRP conditions, for the synthesis of a PAN-Br macroinitiator, were selected to reduce copper catalyst concentration (<100 ppm) and to preserve chain end functionality. Chain extension with styrene by ICAR ATRP was also accomplished with 100 ppm of copper catalyst. The degree of polymerization (DP) of PAN was constant at 55 and the DP of PSt was varied from 5 to 37 by targeting different conversions of styrene during chain extension. Differential scanning calorimetry (DSC) of the block copolymer powders was performed to determine the onset of PAN cross-linking for all block copolymer samples. Interestingly, with increasing PSt contents the cyclization temperature of PAN increased, which indicates interference by PSt with PAN cyclization. Thin films of all PAN-b-PSt samples were cast and AFM imaging was performed to reveal different morphologies, including lamella and bicontinuous. The films were pyrolyzed to create nitrogen-enriched carbon. Pyrolysis yields ranged from 29 to 60% and surface areas ranged from 300 to 400 m2/g. Additionally, SAXS was used to investigate the morphologies of the PAN-b-PSt samples in thin film and their resulting carbons. 

ICAR ATRP to synthesize and morphology studies of PAN-<i>b</i>-PSt block copolymers

248th National Meeting (2014)

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ICAR ATRP to synthesize and morphology studies of PAN-b-PSt block copolymers