Effect of interaction enhancement on rheological response of polypropylene /polybutadiene blend composites

Enhancement interaction between polybutadiene (PB) nanoparticle and polypropylene (PP) matrix by grafts via hydrogen bonding was verified and characterized by dynamic rheological analysis. The introduction of acrylamide (AM) facilitated PB uniform distribution in PP and strengthened interfacial interaction. The correlated structure based on H-bonding interaction leading to the viscoelastic nonlinearity, which restricted polymer relaxation and exhibited different rheological responses. The formation of correlated structure is an energetically favorable process driven by enthalpy, while the dynamics of construction is controlled by diffusion of the binding groups correspondingly, thus, the reconstruction and recoverability depend on the thermodynamic equilibrium distorted by either the shearing or the temperature. Therefore, the recovery ratio increases from 77.31%, 96.53%, to 98.87%, for the blend with identical composition, when increment of temperature from 180, 200–220 °C, is attributed to relaxation enhancement for both the decrement of local viscosity and the acceleration of diffusion.