FT-IR imaging of polymer dissolution by solvent mixtures. 3. Entangled polymer chains with solvents

FT-IR imaging was used to study the dissolution of entangled poly(alpha-methylstyrene) (PAMS) in binary solvent mixtures of systematically varied amounts of methyl isobutyl ketone (MIBK) in deuterated cyclohexane (C6D12). FT-IR images and concentration profiles were obtained, and the results were compared and contrasted with the results of the previously reported unentangled system. It was found that, in many of the solvent systems, the solvent did not dissolve the polymer uniformly at the polymer-solvent interface, causing cracking and roughening of the polymer edge, which can be directly seen in the images. In addition, there was evidence of solvent segregation, which was not seen in the unentangled PAMS.