Characterisation of viscoelastic material properties during curing processes

Paper in proceeding, 2015

© 2015 International Committee on Composite Materials. All rights reserved. The present contribution is toward systematic characterisation of the thermo-viscoelastic properties of a curing epoxy resin system, here we use Huntsman LY5052/HY5052 as model material. The main focus is to verify the existence of equivalence relation (linearity) between time, temperature and degree (time) of cure. As a starting point, the cure kinetics behaviour of the model material has been characterised using DSC equipment and the results have been used to identify parameters in a generic Kamal cure kinetics model. In the subsequent work the DSC data and Kamal model was used to carefully monitor the degree of cure in the resin in all the subsequent experiments. The thermo-viscoelastic response of the curing epoxy was characterised using a dynamic mechanical thermal analyser (DMTA). All the DMTA experiments were focused on rubbery and glassy states only, were the material was subject to tests at various isothermal and non-isothermal loading conditions. The results were used to investigate the linearity between the three factors above (time, temperature and curing time). To summarize, the results indicate that these three parameters indeed obey a linear relationship in the linear viscoelastic regime.