Polycarboxylate Ether Superplasticizer Synthesis, Interplay Between The Structure And Properties

Polycarboxylate superplasticizers based on acrylic acid (AA) and maleic anhydride (MAn) were synthesized via free‐radical copolymerization with an ethylene glycol monomer and characterized. The copolymerization temperature (ranging from 90 to 130 °C) appeared to be the key operating factor governing the chemical structure of the superplasticizers. The chemical structures of the products were analyzed by gel permeation chromatography, whereas an optimized sample was further analyzed by Fourier transform infrared spectroscopy and 1H‐NMR. Superplasticizers of the AA and MAn classes were then incorporated into concrete, and their performances were measured by slump and slump loss tests, where a large dependency of the microstructure on the synthesis temperature was recognized. The optimum temperatures were found to be 90 and 120 °C for the AA and MAn modifiers, respectively. At their own optimum temperatures, the AA and MAn superplasticizer revealed slump losses from 23 to 4 cm and 15 to 5 cm, respectively, after 45 min. The chemical structures of the plasticizers were patterned illustratively to speculate the performance of each superplasticizer according to changes that took place in the backbone length and side‐chain density.