Record curing processes – even in process!
DEA 230 Epsilon – Dielectric Analyzer
Info & Service:
Product Information
Would you like to request more information on a particular product?
We will be happy to send you what you need.
Continue
Service Information
Find out more about our various service offerings.
We are at your assistance!
Continue
Epoxy Resin during Melting and Curing
As temperature is ramped, the multi-frequency loss factor ε" shows a series of dipole relaxation peaks as the epoxy resin passes through its glass transition temperature. The loss factor then rises rapidly as the epoxy melts, reflecting the dramatically increasing ionic mobility in the resin. The ion viscosity curve is derived from the ionic mobility component of the loss factor and is a frequency independent parameter related to the viscosity of the polymer before gelation and to rigidity after gelation. The ion viscosity initially decreases reflecting the effect of increasing temperature on the dynamic viscosity, of the resin. The initiation of reaction, however, competes with the temperature effect by restricting mobility and results in a clearly defined viscosity rises, reflecting the increasing viscosity and cure state of the material. To illustrate the degree of cure, the dielectric cure index may be utilized.
Correlation with Viscosity Measurements (comparison DEA with rheometer data)
A comparison of DEA and rheometer data during the cure of an epoxy-graphite composite system shows that for the first 150 min the mechanical viscosity and ion viscosity curves nearly superimpose, demonstrating the clear correlation between the two properties. Early in the 175°C final hold, the epoxy resin goes through gelation and the mechanical viscosity can no longer be measured. The ion viscosity signal continues to follow the entire reaction, even as the material cures into a rigid glass.
Simultaneous DEA-DMA
Combining the DEA 230 Epsilon with the DMA 242 C, the simultaneous measurement of a polymer's dielectric and dynamic-mechanical properties can be investigated in a single experiment. In this configuration, the compression sample holder of the DMA is used as parallel plate electrodes for the DEA. The techniques are complementary: DMA can clearly identify gelation and vitrification of the resin, while DEA is more sensitive in the viscosity minimum region and to the end of the curing reaction.
Please also visit the following product pages:
)
)
)
print this page
back to top
back
