Model For Deformation Of Polymers Research Articles

Revisiting the mesoscopic Termonia and Smith model for deformation of polymers

Mesoscopic models for polymers have the potential to link macromolecular properties with the mechanical behaviour without being too expensive computationally. An interesting, popular and rather simple model to this end was proposed by Termonia and Smith (1987 Macromolecules 20 835–8). In this model the macromolecular ensemble is viewed as a collection of two-dimensional self-avoiding random walks on a regular lattice whose lattice points represent entanglements. The load is borne by members representing van der Waals bonds as well as macromolecular strands between two entanglement points. Model polymers simulated via this model exhibited remarkable qualitative similarity with real polymers with respect to their molecular weight, entanglement spacing, strain rate and temperature dependence. In this work, we revisit this model and present a detailed reformulation within the framework of a finite deformation finite element scheme. The physical origins of each of the parameters in the model are investigated and inherent assumptions in the model which contribute to its success are critically probed.

The deformation mechanisms of the porous structure of a poly(ethylene terephthalate) nuclear track membrane

Deformation mechanisms of the porous structure of a nuclear track membrane made of poly(ethylene terephthalate) were investigated in the temperature range from 333 to 473 K. It was shown that the pore size of the membrane can both decrease and increase. An analytical equation based on the Alfrey mechanical model for deformation of polymers describes the experimental data satisfactorily over the whole range of temperatures and pore radii of the membrane.