Study on the Compatibility of Acrylic Acid-acrylamide-diethyldiallyl Ammonium Chloride Copolymer with Cement Slurry in CO₂ Environment

This paper investigates the structure and aggregation stability of acrylic acid-acrylamide-diethyldiallylammonium chloride (FA367), followed by an investigation into the impact of acidic CO₂ environments on the interaction between FA367 and cement slurry. The results showed that FA367 formed stable flocculation in cement slurry filtrate, which was not affected by acid gas CO₂. With an FA367 concentration of 0.6%, the fluidity of the cement slurry measures 18.1 cm, but this fluidity is lost upon introducing CO₂. At 90 °C, the compressive strength after 1, 3, and 7 days is 10.23, 77.48, and 62.97%, respectively, compared to pure cement. However, with the addition of CO₂, the compressive strength increases to 27.03, 99.59, and 75.47%, respectively. The interaction between FA367 and cement slurry impedes cement hydration without altering hydration product composition. Instead, it fosters needle-like aggregations between hydration products, affecting the cement stone's compact structure. Upon CO₂ introduction, these needle-like structures diminish, resulting in an overall more intact cement stone structure.