Synthesis of polycarboxylic ether superplasticizers based on the high conversion of EPEG in a transition metal oxide heterogeneous catalytic system

Zhang, Hengtong; Liu, Cailin; Ren, Xianyan; Yang, H. J.

doi:10.1016/j.colsurfa.2022.128780

Cited by 7 publications

(4 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Molecular weight plays an important role in the performance of PCE. Too low a molecular weight leads to insufficient slump of concrete, and too high a molecular weight could decrease the dispersion of cement paste [ 44 ]. The Mn (30,125 and 24,416 Da) of the two PCEs was around 30,000 Da, which could provide a better performance in dispersing cement particles [ 45 ].…”

Section: Resultsmentioning

confidence: 99%

“…Clearly, the addition of PCE delayed the initial and final setting time of cement paste, and similar trends were observed in the study by Zhang et al [ 57 ]. The reason for this could be that the complexation between the carboxyl group on the main chain of PCE and Ca 2+ ions delayed the hydration of cement [ 44 ]. Moreover, it should be noted from Figure 11 b that with increasing SW salinity, the setting time (especially initial setting) was accelerated due to the promoted hydration, which was similar to previous research [ 58 ].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

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

Ren

Zhang

et al. 2023

Polymers

View full text Add to dashboard Cite

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.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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

Ren

Zhang

et al. 2023

Polymers

View full text Add to dashboard Cite

show abstract

“…If the molecular weight is too small, it will affect the slump of the concrete, and if the molecular weight is too large, it will affect the dispersibility of the cement slurry. Therefore, PCE can exhibit good performance only when its molecular weight is within the appropriate range (Zhang et al, 2022). The gel permeation chromatography (GPC) test results of the prepared PCE are shown in Table 6.…”

Section: Molecular Structurementioning

confidence: 99%

Study on rheological, adsorption and hydration properties of cement slurries incorporated with EPEG-based polycarboxylate superplasticizers

Fang,

Wang,

Yan

et al. 2024

Front. Mater.

View full text Add to dashboard Cite

A series of polycarboxylate superplasticizers (PCEs) with different side-chain densities, main chain polymerization degrees, and side-chain lengths were designed and synthesized using a novel highly active ethylene glycol mono vinyl ether polyethylene glycol as the ether monomer. The influence of polycarboxylate ether on the rheological properties, interface adsorption, and hydration characteristics in cement paste was investigated through characterization of charge density, rheological properties, adsorption behavior, and hydration heat. The results indicate that the adsorption process of PCE on cement particles is spontaneous physical adsorption, and the hydration kinetics fitting reveals that the geometric crystal growth exponent n is in the range of 1–2, with needle-like and lamellar hydration products formed. With a decrease in side-chain density, the broadening of molecular weight distribution and the increase of charge density accelerate the flow of slurry, reduces saturation adsorption, and delays cement hydration. A decrease in main chain polymerization degree results in a downward trend in molecular weight and charge density, leading to larger molecular conformations, reduced slurry flow, decreased saturation adsorption, and delayed cement hydration. As the side-chain length of PCE (molecular weight) increases, the charge density decreases, and the molecular conformation exhibits a compact structure with reduced slurry flow, decreased saturation adsorption, and delayed cement hydration. In cases of low side-chain density, short side chains, and low molecular weight, enhanced adsorption capacity and faster adsorption rates are observed, resulting in the lower viscosity and a delay in the cement hydration process.

show abstract

“…12 Weerni et al 13 used MPEG as the side chain and polyacrylic acid as the backbone for polymerization, which required to maintain the grafting reaction for 5 h at 150 C, resulting in a total synthesis time of 6 h or more. Despite the stable synthetic performance and mature technology of the polycarboxylate superplasticizer prepared with methyl allyl polyoxyethylene ether (HPEG) and isopentenol polyoxyethylene ether (TPEG), the relatively low double bond retention rate of HPEG and TPEG has a detrimental effect on the monomer conversion rate, leading to the production of polycarboxylate ethers (PCEs) with low molecular weights, 14 and also require a long preparation time. Li et al 15 synthesized TPEG-AA polyether PCE through free radical polymerization using TPEG and AA.…”

Section: Introductionmentioning

confidence: 99%

Research on the performances of VPEG macromonomer grafted different functional groups to prepare polycarboxylate superplasticizers

Dong,

Liu,

et al. 2024

J of Applied Polymer Sci

View full text Add to dashboard Cite

The advent of novel polyether macromonomer has garnered significant attention within the industrial domain. In this study, a range of polycarboxylate superplasticizers (PCEs) was produced via free radical polymerization, employing a new polyether monomer, 4‐hydroxybutyl vinyl polyethylene glycol ether (VPEG). This monomer served as the predominant component and was grafted with various functional monomers on its main chain. The molecular configuration of the resultant PCEs was discerned through Fourier infrared spectroscopy and gel permeation chromatography, while the surface tension underwent assessment via a surface tension meter. Both the initial and subsequent fluidity of cement paste and mortar were leveraged to ascertain the dispersion and retention efficacy of the synthetic PCEs. The ramifications of diverse functional group grafts of the new polyether monomer on the cement hydration procedure and strength attributes were elucidated via setting time, hydration heat assays of cement paste, SEM analysis, and compressive strength evaluations of mortar. Observations reveal that the carboxylic acid group significantly reduces surface tension, whereas the sulfonic acid group's effect remains minimal. The incorporation of both the amide and sulfonic acid groups marginally impacts the preliminary dispersion efficacy of PCEs but notably affects dispersion retention. Furthermore, these functional groups facilitate cement hydration, expedite the primary setting time of the cement paste, and bolster the initial compressive strength of the mortar. Specifically, the grafted of sodium methacrylsulfonate (SMAS) yields the most noticeable results. Finally, the working mechanism of PCEs with varying molecular structures has been explained in light both theoretical and experimental results. This research offers valuable insights for subsequent investigations into the fabrication of polycarboxylate superplasticizers using the VPEG macromonomer.

show abstract

Synthesis of polycarboxylic ether superplasticizers based on the high conversion of EPEG in a transition metal oxide heterogeneous catalytic system

Cited by 7 publications

References 49 publications

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

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

Study on rheological, adsorption and hydration properties of cement slurries incorporated with EPEG-based polycarboxylate superplasticizers

Research on the performances of VPEG macromonomer grafted different functional groups to prepare polycarboxylate superplasticizers

Contact Info

Product

Resources

About