Synthesis and Properties of a Polycarboxylate
Polycarboxylate superplasticizers (PCEs) emerged as one of the most important superplasticizers for concrete due to their superior performance. (1,2) Compared to other products like polycondensates, they fluidize cement even at low water to cement ratios, require relatively low dosages, and exhibit a long slump retention capability. (35) The
Progresses in Synthesis of Polycarboxylate Superplasticizer
It was shown in Fourier transform infrared spectroscopy (FITR) that the molecular structure of modified polycarboxylate superplasticizer (MPCE) contained sulfonic acid groups, carboxylic acid groups, polyethylene oxide vinyl groups, and other groups and had comb-shaped molecular structure.
Specific molecular design of polycarboxylate polymers
The adsorption of polycarboxylate ether (PCE) superplasticizer on the surface of cementitious materials is a prerequisite for its dispersion and water reduction capability. This paper investigated the adsorption isotherms and kinetics of PCE on montmorillonite (MMT) at 278, 288, 298, and 308 K, respectively.
Synthesis and performance of a modified polycarboxylate
It is well established that the performance of polycarboxylate (PCE) superplasticizers can be severely affected by the composition of individual cements. Here, a novel allylether/maleic anhydride (APEG)-based PCE was synthesized using allyl maleate monomer as a new, additional building block.
An efficient organosilane-modified polycarboxylate dispersant
Herein, four kinds of novel organosilane-modified polycarboxylate dispersants P (AA 3 -APEG 1 -Si x) with different silicone contents ranging from 0 to 0.5 mol were successfully synthesized using acrylic acid (AA), allyl polyethoxyether (APEG-1000) and organosilicon modifier 3- (trimethoxysilyl)propylmethacrylate (MAPTMS) as monomers, and their
- Can Apeg be used to make polycarboxylate superplasticizers?
- The preparation of polycarboxylate superplasticizers using APEG only requires solution polymerization under normal pressure with co-polymer monomers. However, APEG has poor polymerization properties, resulting in a high amount of monomer residue and instability in the performance of the produced superplasticizers.
- Is Apeg a good polymer?
- However, APEG has poor polymerization properties, resulting in a high amount of monomer residue and instability in the performance of the produced superplasticizers. Currently, the production volume of APEG is decreasing year by year.
- Are Apeg polymers able to disperse clay?
- Thereafter, their dispersing ability was probed in the absence and presence of sodium bentonite. Allyl ether-based polycarboxylate (APEG) polymers possessing short side chains were found to exhibit enhanced clay resistance as compared to that of conventional MPEG PCEs holding long pendant chains.
- How are IPEG and hpeg polycarboxylate superplasticizers synthesized in aqueous solution?
- Two different IPEG and HPEG polycarboxylate superplasticizers were synthesized in aqueous solution according to prior literature . Here, the reactions were initiated with ammonium persulfate (APS) while sodium methallyl sulfonate was added as chain transfer agent.
- Which Apeg polymer has a lower d-spacing value?
- For example, 7APEG2 with the lowest anionic charge exhibits a similar d -spacing value to that of the APEG macromonomer. 7APEG4.5 and 7APEG15 exhibit a lower d -spacing value, namely 1.39 nm and 1.19 nm respectively, which again confirms that PCE polymers possessing lower side chain density intercalate less than those with high side chain density.
- Is MPEG a polycarboxylate superplasticizer?
- MPEG was one of the early large monomers used in the production of polycarboxylate superplasticizers. Its synthesis requires two steps: esterification and polymerization, making the process relatively complex.
