Polydisperse polymers: predicting fluctuations, flow and crystallisation

Professor Daniel Read, University of Leeds. Part of the Applied Mathematics seminar series.

All industrial polymeric materials are polydisperse – they contain molecules with a wide range of lengths (and also, commonly, branches too).  There exists a good deal of understanding of how simple liquids containing ideal monodisperse polymers (all the same length) behave when subjected to flow. However, there is a significant challenge in generalising these models to more messy, polydisperse materials. 

In this first half of the talk I will attempt to give a broad introduction to common rheological (flow) measurements, and simple models for the dynamics of entangled polymers. Then (depending on time) I will try to give an overview of recent results for bidisperse polymers (two chain lengths), how these can be generalised to polydiperse materials in order to make quantitative predictions which are helpful to industry. I’ll also show how all this can be packaged up in useful software. And (if time) I might get chance to mention some very recent ongoing work on predicting how polymer flow affects nucleation barriers for crystallization.