Reorientational Dynamics of Dipolar Relaxations in Reactive Polymers

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Mijovic This research is on molecular and phenomenological aspects of dielectric properties of reactive systems in the frequency domain of the dipole relaxation process. The work concerns both monofunctional (non-polymer forming reactants) and multifunctional or polymer forming reactants. The unique feature of the investigation is that it will probe the exact molecular make-up of the reactive system, where the molecular probe is the dipole itself and the response is measured in real time. The analysis is based upon the premise that the dielectric response in the course of reaction must reflect a change in the type and concentration of dipoles and a decrease in their mobility. Reorientational dynamics of dipoles will be experimentally determined as a function of reaction time and temperature over a wide frequency range that will always include the major relaxation process. The observed dielectric behavior will be checked against model predictions. For the monofunctional reactive formulation, we shall seek to establish correlations between the dielectric properties and the known mechanistic kinetics. Modelling of the multifunctional polymer forming system will be based upon the fundamental correlation between the frequency-dependent dielectric constant and its time- dependent counterpart, which will be appropriately modified to account for the distribution of relaxation times in reactive polymers. %%% This fundamental research is of utility in the preparation of polymer-matrix composites in that it will allow a better control of the chemical reactions in their manufacture.