Miscibility of Carboxy-Terminated Polystyrene/Poly[2-(N,N-dimethylamino)ethyl methacrylate] Blends

The miscibility/immiscibility behavior of CPS/PDMAEMA binary blends were investigated by means of DSC and optical microscopy. CPS was prepared by RAFT polymerization. CPS in a molecular weight range of 5 200–14 400 g · mol−1 was found to be miscible with PDMAEMA as shown by the existence of a single glass transition, whereas benzyl‐terminated polystyrene with a similar molecular weight was immiscible with PDMAEMA. DSC results suggested that the carboxylic acid terminal groups effectively operated as miscibility enhancers in polystyrene/PDMAEMA blends. Moreover, it was observed that this effect depended on the molecular weight of CPS and the hydrogen bonding function of solvents. The miscibility of blends of PDMAEMA with carboxy‐terminated telechelic polystyrenes was investigated by means of DSC and optical microscopy. Carboxy‐terminated telechelic polystyrenes formed miscible blends with PDMAEMA, demonstrating that the carboxylic acid terminal groups functioned effectively as miscibility enhancers in PDMAEMA/polystyrene blends.