Influence of polymer latexes on the hydration kinetics of organic inorganic composite cementitious materials: From the perspective of kinetic model simulation

In this study, an enhanced boundary nucleation and growth (BNG) kinetic model with time-dependent nucleation and growth rates is established to analyze how four polymer emulsions—VAE, SiA, ER-SA, and OS-SA—modulate calcium silicate hydrate (CSH) formation throughout the hydration process. By introducing kinetic parameters representing dynamic hydration states (e.g., I n , G ini , t nstop , p up , p down ) and integrating a genetic-algorithm-based automatic fitting procedure, the model accurately reproduces calorimetric curves (RMSE < 5 %) and characterizes how functional groups regulate nucleation suppression, growth inhibition, and the evolution of the maximum critical C-S-H length. VAE shows only slight reductions in In and Gini, implying weak physical adsorption without altering the induction period; SiA causes a marked increase in t nstop and a pronounced drop in I n , quantitatively demonstrating its strong suppression on nucleation via Ca²⁺-affinitive adsorption; ER-SA and OS-SA produce sharp decreases in both I n and G ini together with significant increases in t nstop and p down , consistent with strong Ca²⁺-chelation-driven inhibition on both nucleation and growth. SEM observations corroborate the model-derived trends, showing progressive film formation and steric restriction consistent with the parameter evolution. The proposed time-varying BNG framework provides a quantitative pathway to connect molecular-level interfacial interactions with macroscopic hydration kinetics, offering a practical tool to guide the rational design of polymer-modified cementitious systems. • Developed a time-dependent BNG model to quantify polymer latex effects on CSH nucleation and growth. • Analyzed regulation patterns of four latexes on hydration kinetic parameters (Iₙ, G ini , etc.). • Revealed synergistic mechanisms of physical barriers and chemical adsorption on hydration rates. • SEM validated model predictions of CSH crystal growth inhibition by high latex dosages.