In latex cement slurry system, latex is the most important part of cement slurry. Latex can have a series of physical and chemical interactions with multivalent cations such as calcium ion and aluminum ion in cement slurry phase. Latex cement slurry system is a kind of dispersion system of inorganic components and organic polymer in cement, and its mechanism is quite complex. Experts and scholars at home and abroad have also done a lot of research in this aspect. These studies found that in the process of fierce mixing of latex polymer and cement, the hydration products of cement first combine with latex polymer, and then form a three-dimensional network structure between the hydrated cement phase and the unhydrated cement particles, and finally rely on this three-dimensional network structure to improve the mechanical properties of cement paste It can be improved. We often divide the formation process into three steps

(a) The latex particles can be evenly distributed in the cement slurry after mixing the latex polymer and cement. In the process of cement hydration, the hydration products of cement particles can react with saturated Ca (OH) 2 on the surface of hydrated silicate, and then form a thin layer of calcium silicate.

(b) The water usually confined in the capillary space is the free water between polymer latex particles and cement colloid unit structure. With the continuous hydration process, the free water confined in the capillary space also decreases. In this way, latex particles will form a continuous latex polymer coating on the surface of cement particles which have not yet participated in the hydration reaction, and it can bond with the coating surface of silicate mixture. However, since the pore size of cement slurry is generally in the range of 100 nm to hundreds of nm, the groups in polymer latex particles (such as those containing - COOH and - COO polyacrylic acid latex) that automatically enter into the mixture or adsorb larger than the pore size will react with calcium ions produced in the hydration process of cement on the surface of Ca (OH) Ψ solid particles or silicate hydrate, and then react with calcium ions This makes the performance of latex cement slurry system changed.

(c) Polymer latex particles are separated from the liquid phase of cement slurry system and can form a continuous film on the surface of cement hydrate. This film can "hinge" the unit network structure of hydration products of cement particles together, so that it can be firmly bonded into a solid cement stone. The filamentous film of these latex polymers can cross the defects and microcracks of cement paste, and shuttle and connect with each other, which not only reduces the stress concentration at the defects and microcracks of cement paste, but also increases the deformation capacity of cement paste, and finally improves the fracture resistance, permeability resistance, filtration reduction and gas channeling resistance of polymer latex cement paste.