Infrared spectroscopy is a fine tool with which to experimentally explore the effect of chain connectivity and functional group accessibility in hydrogen-bonded polymer blends. Such factors directly affect the fraction of intermolecular hydrogen-bonded groups that are formed and effectively reduce the hydrogen-bonding contribution to the free energy of mixing vis-A-vis analogous low-molar-mass analogues. In this study we report the results obtained from blends of copolymers containing vinyl cinnamate (VCIN) with copolymers containing 4-vinylphenol. The VCIN segment undergoes facile photocross-linking upon exposure to UV radiation, permitting the effect of cross-linking on functional group accessibility and phase behavior to be studied.