Study of the two-component segmental dynamics of poly(vinylethylene)/polyisoprene miscible blends

The two components of the segmental dynamics of poly(vinylethylene) (PVE) and polyisoprene (PIP) miscible blends, as observed dielectrically, are resolved and analyzed. This analysis is based upon a generalization of the CONTIN algorithm for inverse Laplace transformations presented in a previous publication. By means of this procedure, a distribution of relaxation times, corresponding to Debye-like processes, is directly obtained from the dielectric data in the frequency domain. This method allows a straightforward comparison between our dielectric results and those previously reported from 2D-NMR measurements. The calculated distributions have a bimodal character, i.e., two different dynamical processes contribute to the whole dielectric alpha-relaxation of the blends. It is found that, although the faster process resembles to the PIP dynamics, the slower contribution involves the dynamics of both the PIP and PVE units. This fact explains the differences between the dielectric and nuclear magnetic resonance results.