Title: A New Type of Superplasticizer Possessing Dendrimeric Structure
Author(s): Manuel Ilg and Johann Plank
Publication: Symposium Paper
Appears on pages(s): 89-102
Keywords: hyperbranched superplasticizer; polyglycerol; dendrimeric structure; dispersion; calorimetry; sulfate tolerance; small molecule; admixture.
In this study, the synthesis of a new superplasticizer is described which is composed of a hyperbranched polyglycerol scaffold with multiple carboxylate groups in the periphery and one single side chain comprised of ethylene oxide as well as propylene oxide subunits at the branching point. This hyperbranched superplasticizer was obtained via a three-step synthesis from Jeffamine and glycidol by anionic ring-opening polymerization. Additionally, a linear small molecule was synthesized as reference using a Michael type reaction to assess the effect of the dendrimeric structural motif on the dispersing capability and application properties (e.g. slump retention, sulfate tolerance). Both polymers were characterized by SEC and their anionicity was captured by charge titration. Furthermore, mini-slump tests and heat flow calorimetric measurements were conducted. For the hyperbranched superplasticizer a superior dispersing performance was found compared to the reference, resulting from improved steric hindrance induced by the dendrimeric polyglycerol.