40 years of PCE superplasticizers - History, current state-of-the-art and an outlook

Lei, Lei; Hirata, Tsuyoshi; Plank, Johann

doi:10.1016/j.cemconres.2022.106826

Cited by 79 publications

(44 citation statements)

References 76 publications

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“…It is commonly acknowledged that superplasticizers derive their effectiveness from adsorption on binder particles or early hydrates, such as ettringite, monosulfate, syngenite, portlandite, and gypsum . Generally, superplasticizers achieve dispersion via two distinct mechanisms: electrostatic repulsion , and steric hindrance.…”

Section: Introductionmentioning

confidence: 99%

Dispersing Efficacy of Tailored IPEG PCEs in AAS Binders: Elucidating the Impact of PCE Molecular Weight

Chen

Lei

et al. 2023

Ind. Eng. Chem. Res.

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In this study, the impact of the molecular weight of isoprenol ether-based (IPEG) polycarboxylate superplasticizers on the dispersing effectiveness in sodium hydroxide-activated slag binder and slag composite cement was investigated. For this purpose, a series of IPEG polycarboxylate ether (PCE) superplasticizers possessing the same anionicity and the same side chain length but varying molecular weights (13,000−400,000 Da) were prepared. The synthesized PCE polymers were then subjected to application-related tests. It was found that their dispersing capacity in the AAS binder differed significantly and that IPEG PCE polymers possessing higher molecular weight generally were more effective. Surprisingly, it was also noticed that in the slag composite cement (90% slag, 10% OPC), generally, higher doses of the PCEs were required than in the OPC-free AAS binder system. Moreover, the working mechanism behind the enhanced dispersing ability of high M w IPEG PCEs was studied via adsorption and adsorbed layer thickness (ALT) measurements. To determine the ALT of the adsorbed PCE polymers, phosphate-modified polystyrene nanoparticles were selected as a model substrate. Results from dynamic light scattering revealed that high M w PCEs produce thicker adsorbed layers, which highly benefits the dispersing power of the PCE polymers stemming from enhanced steric hindrance. Finally, different models for the adsorbed conformations of those IPEG PCEs are proposed based on their individual molecular characteristics.

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Section: Introductionmentioning

confidence: 99%

Dispersing Efficacy of Tailored IPEG PCEs in AAS Binders: Elucidating the Impact of PCE Molecular Weight

Chen

Lei

et al. 2023

Ind. Eng. Chem. Res.

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“…PCs have been largely applied to the field of construction since its invention [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. PCs are formed by the main chain with carboxylate groups and the polyethylene oxide segment side chain, exhibiting excellent water-reducing properties and a high compatibility and processability in cement-based material; nowadays PCs are accepted as the most efficient dispersant [ 15 , 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Triblock Polycarboxylate Superplasticizers with Well-Defined Structure and Its Dispersing Performance in β-Hemihydrate Gypsum

Guo¹,

Gao²,

Jiang³

et al. 2023

Molecules

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In this work, a novel AaBAb−type triblock polycarboxylate superplasticizers (PCEs) with well defined molecular structures were designed and synthesized, firstly, by reversible addition−fragmentation chain transfer (RAFT) polymerization, to explore the structure–property relationship PCEs in the β−hemihydrate gypsum (β−HH) system. Three PCEs with the same molecular weight and different structure were obtained by changing the feed ratio of the RAFT agent, initiator, and monomer. The effect of the chemical structure of PCEs on their dispersing property and water reduction capacity were assessed in gypsum by measuring the flowability of pastes and the adsorption ability of PCEs on gypsum. Results showed that among three PCEs, when the monomer ratio is 5:1 and a:b = 1:1, PCE−1 exhibited a higher working efficiency, verifying the contribution of regulating structural parameters to the improvement in performances of gypsum paste, because PCE−1 showed the strongest binding capacity with calcium ions due to the relatively equal amount of carboxyl groups at both ends. The AaBAb−type PCEs provide a special advantage over the conventional comb polymer to understand the relation between the structure and property of PCEs, and a direction for further development of PCEs of high performance.

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“…Polycarboxylate (PCE) is a comb polymer with a strong molecular structure design, and it is considered to be the best dispersing agent for cement-based materials [ 21 ]. Based on the structure of PCE comb copolymer with both carboxyl and polyethylene glycol (PEO) side chains, PCE copolymer produces electrostatic repulsion and steric hindrance, so it has excellent performance including long-term retention, higher water reduction rate, and stronger environmental protection [ 22 , 23 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Salinity and Polycarboxylate Superplasticizer on Fresh Property of Seawater-Blended Cement

Ren

Zhang

et al. 2023

Polymers

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The salinity of seawater can affect the properties of mixtures of polycarboxylate superplasticizer (PCE) and seawater. The purpose of this research is to study the effect of different salinities of water on the property of seawater-mixed cement slurry. Two PCE types with different side chain lengths and acid–ether ratios were used. Their physicochemical properties were explained by nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), turbidimetry, and dynamic light scattering (DLS) analysis. The performance of the PCEs was measured using slump, rheological energy, and solidification time. Finally, by measuring the adsorption volume, adsorption layer thickness, and water film thickness (WFT), the mechanisms involved in performance modification were studied. The results show that the workability and rheological performances of seawater-mixed cement paste are decreased by increasing salinity. With the increase in salinity, the minislump of the seawater-blended cement pastes with two PCEs decreased from 285 mm to 120 mm and from 280 mm to 78 mm, respectively, and the thixotropic areas were increased from less than 2000 Pa/s to above 10,000 Pa/s. Moreover, the adsorption amount of the two PCEs in the cement mixed with high-salinity seawater decreased by 55.99% and 71.56%, respectively, and the thickness of the adsorption layer and water film was decreased with increasing salinity. Compared with the two PCEs, PCE with long side chains and a high acid–ether ratio provided better salt resistance.

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40 years of PCE superplasticizers - History, current state-of-the-art and an outlook

Cited by 79 publications

References 76 publications

Dispersing Efficacy of Tailored IPEG PCEs in AAS Binders: Elucidating the Impact of PCE Molecular Weight

Dispersing Efficacy of Tailored IPEG PCEs in AAS Binders: Elucidating the Impact of PCE Molecular Weight

Synthesis of Triblock Polycarboxylate Superplasticizers with Well-Defined Structure and Its Dispersing Performance in β-Hemihydrate Gypsum

Effect of Salinity and Polycarboxylate Superplasticizer on Fresh Property of Seawater-Blended Cement

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