Thermodynamic phase analysis of acrylic polymer/hindered phenol hybrids: Effects of hydrogen bonding strength

The upper critical solution temperature-type thermodynamic phase diagrams of acrylic polymer/hindered phenols damping materials were drawn to investigate its'long-term stability. We report that increasing the intermolecular hydrogen bonding strength between the hindered phenol and carbonyl groups of PBMA could effectively reduce the Flory-Huggins interaction parameter χ. Meanwhile, increasing the steric hindrance of the phenolic hydroxyl groups and the sizes of small molecules may sufficiently weaken intramolecular hydrogen bonding interactions. These effects suppress the self-aggregation of small molecules and improve the long-term stability. The phase diagrams are essential not only for the structural optimization of small molecules, but also for determining the composition ratio of these novel damping materials.154