In this research, the mechanism of polymer latex modified
cement was investigated. This mechanism contained physical
and chemical aspects. When the polymer latex has no active
groups which can react with hydration products, the mechanism
in this modified system just contained physical modification mechanism.
The polymer latex film covered the surface of crystals and
filled in the cracks and pores, increasing the flexural strength of
the modified cement. At the same time, the polymer latex film
occupied the site of hydration products resulting in a lower compressive
strength. However, when the polymer latex contained
the active groups in their polymer chains, the mechanism included
physical and chemical modification mechanisms. The physical
modification mechanism was the same with the polymer latex
which have no active groups. In the chemical modification mechanism,
the active groups reacted with the hydration products, linking
the polymer latex chains together. These chemical reactions
created a 3D network structure, which increased the flexural
strength of the modified ceme