The Application of Nutting's Equation to the Viscoelastic Behavior of Certain Polymeric Systems

Abstract

The Nutting equation ε=ψ×σβ×tn , where ε=strain, σ=stress, t=time, and ψ, β, and n are material constants, is applicable to a large number of polymeric systems, such as plasticized polyvinyl chloride, styrene‐butadiene copolymers, polystyrene. It has been shown that the material constant n is closely related to the damping coefficient as obtained from dynamic mechanical measurements The temperature dependence of n and δ (damping coefficient) are about the same; and, in some cases, there exists a simple quantitative relationship between the two constants. A mathematical derivation of the relationship between n and δ is given and a physical interpretation of the dimensional changes in the Nutting equation, in terms of complex moduli, is presented. Furthermore, it is shown that, in the case of styrene‐butadiene copolymer,n varies with the differences in gel content and gel structure.