It is well established that the performance of super-plasticizer (PCE) is mostly determined by its molecular structure. This research tends to combine PCE with hyperbranched polymer and design PCE molecule structure, aiming to enhance the water-reducing performance of PCE. Here, a novel PCE with hyperbranched molecular structure (HBPCE) was synthesized through two steps. With diallylamine, methyl propenoate and trihydroxymethylpropane as raw material, firstly, a hyperbranched monomer B was successfully synthesized. Then through free radical polymerization of methylallylpoly oxygenethene ether 2400 (HPEG 2400), propenoic acid (AA) and the monomer B in aqueous solution, the final product HBPCE was obtained. 1 H nuclear magnetic resonance (1H NMR) and infrared spectroscopy (IR) measurements were used for structural characterization, and gel chromatography was used to measure the molecular weight distribution of HBPCE. In addition, performances of HBPCE in cement paste were investigated. It is concluded that HBPCE has a good dispersing effect on cement paste and the water reduction ratio is up to 38.6%.Since came out in the 1980s, polycarboxylate superplasticizers (PCE) have been increasingly used in cement and concrete industry, such as buildings, bridges and dams fields. [1][2][3] Traditional PCE polymers are composed of polyethylene main chain, poly (ethylene glycol) branch chain and carboxylic side groups, [4][5][6][7][8] and it's convenient to achieve diverse functions and specially solve some problems in concrete engineering because their chemical structure has the potential to be modified. [9][10][11] As an important type of concrete admixture, the main function of superplasticizers is to increase the dispersion of cement paste, [12,13] leading to a low water-to-cement ratio (w/c) and high strength concrete. Compared with other water reducing agents, PCE exhibits excellent water-reducing performance, outstanding slump retention ability, low dosage and wide range of adaptability. [14][15][16][17][18][19][20] More importantly, PCE's performances are able to get breakthrough by means of adjusting and optimizing their molecular structure.The relationship between the structure and performance of PCE is determined by its working mechanism. Recent years, many researches on the working mechanisms of PCE have been carried out, [21][22][23] however, working mechanisms of PCE can hardly be confirmed with certainty at present. The effect of chemical structure of PCE on the dispersion effectiveness is still not sure, and the reason may be that the structure of PCE polymers is complex and changeable. Even so, it is certain that the mechanism behind the dispersion effectiveness of PCE is based on steric hindrance between cement particles as well as electrostatic repulsion forces. [24] Hyperbranched polymer, a kind of highly branched polymer in macromolecule field, has attracted considerable attention because of its remarkable properties, such as high solubility, low viscosity, multifunction, approximately globular three-dime...
