Linear viscoelasticity of an acrylate IPN, analysis and micromechanical modeling.

Abstract

An amorphous acrylate interpenetrated polymer network (IPN) was made in the laboratory and tested by dynamic mechanical analysis. Using frequency sweep tests, it was shown that the time-temperature superposition principle applies to the double network. Moreover, a generalized Maxwell model with forty Maxwell branches successfully reproduced the material's linear viscoelasticity. Using temperature sweep tests, the linear viscoelasticity of the IPN has been estimated using micromechanics, applying both mean-field homogenization models and fast Fourier transform (FFT)-based homogenization techniques. This modeling effort allowed discussing the mechanical interactions of the simple network. The microstructure of a second network, defined by a self-avoiding random walk, embedded in a continuous medium, in place of the first network, is shown to provide with satisfactory estimates of the linear viscoelasticity of the IPNs.