Nonlinear damping of associative polymers

Stress relaxation measurements under step strain γ are frequently utilized to characterize the nonlinear stress responses of polymeric materials. The reduction degree of the stress amplitude with increasing step strain is quantified by the so-called damping function, h(γ). In this review, we summarize a recent progress in molecular understanding of the damping behavior of associative polymers from both the experimental and theoretical perspectives. The damping is related to the rupture and reconstruction of associative network after applying step strain and before the terminal stress relaxation. Incorporation of this mechanism into the classic sticky Rouse model through the conformation pre-averaging protocol enables quantitative prediction of the damping behavior of randomly associating linear polymers as well as end-associative star polymers, both in the unentangled state.

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