Control of interaction strength in hydrogen-bonded polymer blends via the density of the hydroxyl group

Deuterium-labeled polystyrene modified by random distributions of the comonomer p-(1,1,1,3,3,3-hexafluoro-2-hydroxyisopropyl)-alpha- methylstyrene [DPS(OH)] has been blended with poly(butyl methacrylate) (PBMA) and studied with small-angle neutron scattering(SANS). Miscibility is induced via hydrogen bonding between the DPS(OH) hydroxyl group and PBMA carbonyl groups. As the density of the hydroxyl group increases, the susceptibilities of the related blends decrease, while those of the pure DPS(OH) increase. The extrapolated spinodal temperature increases linearly with comonomer density, and the hydrogen-bond enthalpy deduced from the SANS data is in good agreement with previously reported values.