Abstract:
The project concerned the development of a novel measurement and analysis tool,
designed to aid the study of cure in thermosetting polymers. Cure is the
irreversible process whereby an initially liquid (unreacted) resin turns into a
rubbery solid and eventually into a rigid crosslinked glass. The process usually
requires the application of heat to proceed to completion. The changes in
structure are reflected in changing mobilities of electrically charged species
in the resin and dielectric signals can therefore be used to monitor the
progress of cure. In this project, the normal heating–up of the resin was
accompanied by a superimposed sinusoidal temperature variation of +/- 1°C.
Deconvolution of the resulting dielectric signal into its reversible and
irreversible components made it possible to distinguish between the signal
contributions arising from the temperature change alone and from those directly
contributable to the irreversible chemical chain extension and crosslinking.
This proves the original hypothesis put forward in the proposal. The new ideas
generated during the course of the project enabled us to obtain significant
follow-on funding from the EPSRC. A new dielectric cell has been designed, which
will be used in attempting to track particle dispersion in thermosetting
nanocomposit
