Investigating Secondary Equilibration in Thermoplastic Ionomers Under a Thermo-Electric Field

Ionomers are polymers containing a small fraction of charged groups in their polymer backbone. These ionic groups link together to form ionic aggregates which act as temporary cross-links. On heating over the ionic dissociation temperature, these ionic aggregates become mobile in the melt and reaggregate upon cooling. The structure and dynamic behavior of these ionic aggregates gives rise to interesting mechanical and functional properties of the ionomers. Thermal processing of ionomers leads to secondary equilibration of these ionic aggregates. We study this phenomenon of secondary equilibration on application of a thermo-electric field where an electrostatic field is maintained over the ionomer melt. The end goal is to achieve control over the size and distribution of the ionic aggregates by means of an external electric field. The characterization techniques utilized to study the onset of secondary equilibration are UV-Vis Spectroscopy, Differential Scanning Calorimetry, Fourier Transfer Infrared Spectroscopy and Attenuated Total Reflectance analysis. The results indicate that the phenomenon of secondary equilibration is present under the application of a thermoelectric field as indicated by change in spectral and thermal data. A fundamental understanding of the secondary equilibration phenomenon and eventual prevention of the onset of secondary equilibration will lead to long term control of the ionic aggregates by means of an external electric field which will improve the function and utility of these ionomeric materials.