Water-Redispersible Low-T_g Acrylic Powders for the Modification of Hydraulic Binder Compositions

摘要

Water-redispersible,low-T_g acrylic polymer powders are obtained in a free-flowing form by spray drying the structured aqueous dispersions.Powder sticking and caking phenomena are minimized thanks to the heterogeneous particla morphology achieved through a sequential polymerization technique.Redispersibility is reached by the presence of functional monomers containing acid groups,properly distributed in the polymer particles.The influence of the different synthesis parameters on the drying and redispersion processes is discussed.The acrylic powders developed here are well suited for the modification of Portland cement mortars,giving performances comparable to their corresponding "mother"latices.