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

ABSTRACT

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.