. The apparent solution kp may be
different from kp,g in cases of polar intersegmental interactions.
It has been reported that, because of hydrogen bonding
between the monomers and between the solvent and carboxyl
groups in the polar solvents, the acid exhibited an associated
structure forming oligmeric associates and monomer–solvent
association complexes [14,16], which would be result in higher
reaction rate than that in the melt.