Synthesis and properties of multi‐armed polycarboxylate superplasticizer modified by β‐cyclodextrin

Abstract

AbstractThe polycarboxylate superplasticizer with a multi‐armed structure (multi‐armed‐PCE) was synthesized via RAFT polymerization of pentaerythritol triacrylate, acrylic acid, macro‐monomer polyethylene glycol ether (GPEG) and a certain amount of β‐cyclodextrin esterified by maleic anhydride (MA‐β‐CD). The precise structure of the multi‐armed‐PCE was characterized by NMR, FTIR, and GPC. Benefitting from the stronger steric hindrance effect provided by the multi‐armed topology and MA‐β‐CD side chains, the polymer exhibited efficient dispersion and fluidity retention properties. As a result, the water reduction rate of the polymer multi‐armed‐PCE can reach 32.5% under the condition of 0.28% dosage. Compared with comb‐like PCE‐B, the cement paste containing multi‐armed‐PCE exhibited better fluidity retention of 2 hours. Moreover, the multi‐armed‐PCE can significantly increase the mechanical strength of cement hydration products, which can provide potential prospect for the design of high‐strength concrete products.