Polymer latexes with varied glass transition temperature for cement
The influence of styrene-acrylate latexes with varied glass transition temperature (Tg) on the cement hydration was analysed in a research work.
Results show that polymer latexes with varied Tg retard cement hydration to different extents. Specifically, low Tg polymer shows stronger retardation effect than the high Tg polymer. Despite similar surface charges, colloidal particles with lower Tg exhibit higher affinity to surface of cement grains than the high Tg polymer, indicated by the higher adsorption amount and denser covering layer.
Stronger retardation
The low Tg polymer experiences particle packing, deforming, and film forming processes along with the consumption of water during cement hydration, which eventually produces a covering layer of polymer surrounding cement grains. However, for the high Tg polymer, film forming process is absent. Consequently, the higher adsorption amount and the film-formation process along with cement hydration are the two reasons for the stronger retardation effect of the low Tg polymer.
The study is published in: J. Appl. Polym. Sci. 2017, 134, 45264.
