Kinetic Ising model for polymer dynamics: Applications to dielectric relaxation and dynamic depolarized light scattering

Abstract

We introduce a new one-dimensional kinetic Ising model to study the cooperative dynamics of linear chain molecules. Correlation functions for the model are calculated approximately. We discuss the connection between these correlation functions and certain relaxation functions that can be measured by dielectric and dynamic depolarized light scattering experiments. These relaxiation functions are extremely well represented by the Williams–Watts empirical function φ(t)=exp[−(t/τ)β] with β between 1/2 and 3/4. This is in reasonable agreement with both dielectric and light scattering experiments on amorphous polymers. Our results lead to a microscopic interpretation of this ‘‘universal’’ nonexponential decay function.