The formation and dissociation of networks formed by polymer‐plasticizer interactions

Systems containing polycarbonate and aromatic plasticizers with nitro groups were investigated. It was found, experimentally, that in these systems the tensile strength and tensile modulus increased. These changes of mechanical properties termed as antiplasticization can be interpreted as a result of crosslinking by the van der Waals bonds between the macromolecules and molecules of plasticizer. Considerations concerning the equilibrium of formation and dissociatiation of these networks were made in order to explain the phenomenon of threshold concentration of the plasticizer, below which antiplasticization and above which plasticization occur, as well as the nonlinear dependence of the glass transition temperature on the plasticizer concentration.