(230e) Polycarboxylate Ether Cement Superplasticizers Containing Copolymer Backbones with Improved Rheology Performance

Polycarboxylate ether (PCE) superplasticizers are used in cement to reduce the water level necessary to achieve flow and the desired open time for workability, thus reducing the impact of water’s deleterious effect on concrete strength. Standard PCEs used in cements are graft copolymers consisting of a polyacrylic acid (PAA) backbone with acrylic ester units containing polyethylene glycol (PEG) side chains. Unfortunately, while PAA-based PCEs show equal or better performance initially, the alkalinity of the cement leads to rapid hydrolysis and loss of slump flow. We have found that using an acrylic acid copolymer backbones to produce PCEs provides excellent flow and open time characteristics. The acrylic acid copolymers are statistical copolymers of acrylic acid and hydrophobic acryloyl morpholine (ACMO). This acrlylic acid and acryloyl morpholine copolymer based PCE has shown extended open time for workability, indicating better stability in cement formulation than PAA based PCE.