Intermacromolecular complexation due to specific interactions. 6. Miscibility and complexation between Poly{Styrene-co-[p-(2-Hydroxypropan-2-yl)Styrene]}and poly[n-butyl Methacrylate-co-(4-vinylpyridine)]

In recent years, considerable attention has been focused on polymer miscibility and Complexation due to hydrogen bonding. Monodisperse, proton-donating polystyrene (PS), that is, poly{styrene-co-p-(2-hydroxypropan-2-yl)styrene]} PS(t-OH)], was synthesized via chemical modification of polystyrene. Polyn-butyl methacrylate-co-(4-vinylpyridine)] (BVPy), as a proton acceptor, was prepared by free-radical copolymerization of the corresponding monomers at low conversion. In organic solutions of PS(t-OH)/BVPy blends, viscometry was employed to study the Complexation behavior. Solvents with different proton-accepting abilities were used and hence proved to exert distinctive effects on solution complexation. In very dilute solutions, the complex aggregate was observed by static and dynamic light scattering (LS). Differential scanning calorimetry (DSC) investigation proved that miscibility could be greatly enhanced when a small amount of hydrogen bonding was introduced into the originally immiscible PS/PBMA (polybutyl methacrylate) system. Although it was found that the T _g of the hydrogen-bonding polymer complexes occurred at higher temperatures with respect to linear weight-average value, DSC measurement alone could not accurately distinguish polymer complexes from ordinary miscible blends. Based on the data of miscibility from DSC and complexation from vis-cometry in 1,2-dichloroethane for a few tens of blends, which cover broad ranges of the contents of interaction sites, a map showing the immiscibility-miscibility-complexation transitions by strengthening the hydrogen bonding for the system of PS(t-OH)/BVPy was successfully constructed.