The binary poly(acetoxystyrene)/poly(ethylene oxide) (PAS/PEO) blend system is fully miscible, as evidenced by a single glass transition temperature over a full range of compositions when analyzed by differential scanning calorimetry analysis, as a result of weak C−H···O hydrogen-bonding interactions between the carbonyl groups of PAS and the methylene groups of PEO. One- and two-dimensional correlation spectroscopies provide positive evidence for this specific interaction between the two polymers. In addition, a negative polymer−polymer interaction parameter “χ12” was calculated using the Flory−Huggins equation based on the melting depression of PEO. The presence of an amorphous PAS phase results in a reduction in the spherulite growth rate of PEO. Both the values of nucleation constant and the surface free energy of chain folding of PEO decrease with increasing PAS content, which indicates that the crystallization ability of PEO increases correspondingly.