Title: Meta-Analysis of PCE Structures as Dispersants in Cementitious Materials

Author(s): Thomas Wagner, Tobias Lange, Torben Gädt

Publication: Symposium Paper

Volume: 354

Issue:

Appears on pages(s): 61-74

Keywords: cement; dispersant; meta-analysis; polycarboxylate ether; rheology; slump flow; yield stress

DOI: 10.14359/51736062

Date: 7/1/2022

Abstract:
The structure-activity relationship of dispersants in cement was explored by conducting a meta-analysis of academic publications on polycarboxylate ether (PCE). Therefore, structural data of PCE dispersants was collected from the academic literature together with the corresponding mini-slump data. The structures were summarized using the structural parameters P (the number of repeat units of the side chain), n (the number of repeat units in the backbone), and N (the number of monomers per repeat unit). It was found that the distribution of side-chain length is multimodal, reflecting the availability of commercial macromonomers based on poly(ethylene glycol) (PEG). For the mean values, it was found P = 38.5, N = 4.7, and n = 24.3. The most frequently employed charge-bearing monomers are acrylic acid, methacrylic acid, and maleic acid. The main macromonomers are either based on methoxy poly(ethylene glycol) methacrylate, isoprenyl-poly(ethylene glycol) (IPEG), methallyl-PEG, or allyl-PEG. Additionally, rheology data from mini-slump tests containing this PCE was transformed into yield stress data. In an attempt to identify the most dosage-efficient PCE structures, the yield stress data were compared with PCE structural descriptors and dosage. It was found that PCE with a P/N ratio between 6-12 and an adsorption constant between 10-100 show the highest dosage efficiency.