Synthesis and Performance of Polycarboxylate Superplasticizers with Hydrophobic Side Chains

Abstract

Based on polycarboxylate chemistry, polycarboxylate superplasticizers (PCs) with hydrophobic side chains were synthesized through radical copolymerization reaction. The molecular weight and polydispersity index were analyzed by gel permeation chromatograph (GPC), and the results showed the same structural information. The performances of PCs in cement paste were tested by measuring the fluidity and fluidity retention. The slump and the compressive strengths of concrete were also determined. Additionally, the foaming behavior of PCs was investigated by the foam volume, the surface tension of PCs aqueous solution,and the air content of concrete. According to the data, the hydrophobic side chains of PCs may affect the hydration reaction of cement resulting in better workability.

Influence of high mixing intensity on rheology, hydration, and microstructure of fresh state cement paste

“…Similar to the impact of mixing on the silicate phases, it is likely that the increased mixing intensity will also impact the formation of hydrates precipitating from the aluminate phases. Ettringite has a considerable impact on the rheological behavior and stiffening of fresh cement pastes [40,48] within the paste matrix and air will also affect rheological properties [51,52]. Thus, the greater sensitivity to mixing intensity seen in the plasticized mixtures as compared to the non-plasticized mixtures could be due to the polycarboxylate-based admixture inducing changes within the paste that modified the fundamental rheological response of the paste systems.…”

Progresses in Synthesis of Polycarboxylate Superplasticizer

“…e results showed that fractions of higher molar weight were adsorbed to a larger extent than fractions of lower molecular weight. Yang [36] used azobisisobutylamidine hydrochloride (AIBA•2HCl) as initiator in polymerization of polyoxyethylene allyl ether (APEG) and maleic anhydride (MA) to synthesize PCE-1. Also, Isoamyl enol polyoxyethylene ether (TPEG), the activity of acrylic acid (AA) and methacrylic sulfonate (MAS) was used to synthesize PCE-2.…”