The Synthesis of and Study on AA/SSS/APO Terpolymer Retarder

Using acrylic acid (AA), sodium p-styrene sulfonate (SSS) and an alkylene monomer (with long hydrophilic chain) (APO) as raw materials, a terpolymer retarder, BH, was synthesized through water solution polymerization, with ammonium persulfate as initiator. Using single factor analysis, the optimum molar ratio of these monomers was determined to be 1 (AA):1 (SSS):0.1 (APO), the mass fraction of monomer's concentration 30%, the concentration of initiator, 4% (m/m), pH 5, and reaction time at 80℃, 14 hours. The molecular structure of the polymer was characterized by IR spectroscopy. Cement slurries treated with BH were studied on their retarding performance, temperature sensitivity, rheology, free water and compressive strength. It showed that the BH can be used in a wide range of temperatures (90-170℃), and is not sensitive to temperature changes. At BH concentration of 2.75% and 170℃, the BH-treated cement slurry has a thickening time of 356 min. The addition of BH improves the rheology of cement slurry, and has little, if any, effect on the strength of set cement. Cement slurries treated with BH can be used in salt concentrations of up to 16%.