Branched alkyl polyethers as novel defoamers for concrete

In this study, we report the application of branched alkyl polyethers as novel defoamers for concrete for the first time. A series of branched polyether defoamers with the same ethylene oxide (EO) unit content, but different branched chain lengths and branched degrees were prepared. The properties of the branched defoamers in aqueous solutions, and fresh and hardened cementitious mortars were evaluated. The results show that compared with traditional linear polyether defoamers, the branched defoamers exhibited better water solubility, meanwhile higher defoaming ability in both solutions and mortars. The defoamer having a longer branched chain length and higher branched degree exhibited higher defoaming ability. The hardened mortar specimens mixed with the branched defoamers also exhibited higher mechanical performance. This study found great potential of the branched alkyl polyethers for the applications as novel defoamers.