Dielectric spectroscopy for the characterization of the microstructure of latexes

A TSC (thermally stimulated current) study of n-butyl acrylate styrene copolymers has shown the influence of polymerization conditions on the microstructure of those amorphous copolymers. The semicontinuous introduction of monomers gives a relatively homogeneous statistical copolymer. Indeed the TSC peak observed around T _g is due to elementary process following a single compensation law. DSC data (differential scanning calorimetry) are consistent with this result since the DSC trace is characteristic of a monophasic polymer. The stepwise introduction of monomers leads to a block copolymer. Two TSC peaks are observed in the same temperature region, while the DSC spectrum only shows the existence of a broad transition region. The fine structure of the TSC peaks is well described by two compensation laws and thus confirms the presence of two well-resolved mechanisms. These results are indicative of a core shell structure