high solids polycarboxylate synthesis for cement superplasticizers

摘要

The present invention provides efficient methods for forming a high solids polymeric polyacid or a comb polymer useful as a superplasticizer or dispersant comprising heating to 80 to 100 ° C for a first period of time and then sequentially heating to a second temperature 150 to 250 ° C for a second time a wet reaction mixture having a solids content of 80 to 99 wt% and comprising 15 to 60 wt% of one or more ethylenically unsaturated acids or a salt thereof from 37 to 76.99% by weight of one or more polyether polyols, alkyl polyether polyols, polyether amines or alkyl polyether amines in the presence of (i) from 0.01 to 1% by weight of one or more soluble radical initiators in water or redox pairs and (ii) from 2 to 22% by weight of one or more phosphorus oxide-containing compounds, all weights based on the total weight of the wet reaction mixture.