Redispersible latex powder is used in one-component JS waterproof coating, polystyrene board bonding mortar for building insulation, flexible surface protection mortar, polystyrene particle thermal insulation coating, tile adhesive, self-leveling mortar, dry-mixed mortar, putty, etc. The field of modifying inorganic gelling materials has been widely used.
Adding redispersible latex powder to putty powder can increase its strength, have strong adhesion and mechanical properties, and help to improve hardness. It has good water resistance, permeability, and excellent durability. Alkaline, wear-resistant, and can improve water retention, increase open time, and enhance durability.
When the redispersible latex powder is stirred evenly in the putty powder and mixed with water, it is dispersed into fine polymer particles; cement gel is gradually formed through the initial hydration of cement, and the liquid phase is formed by Ca(OH)2 in the hydration process. Saturated, while the latex powder forms polymer particles and deposits on the surface of the cement gel/unhydrated cement particle mixture; as the cement is further hydrated, the water in the capillaries decreases, and the polymer particles are gradually restricted in the capillaries. Adhesive/unhydrated cement particle mixture and filler surface form a close-packed layer; under the action of hydration reaction, base layer absorption and surface evaporation, the water is further reduced, and the formed stacked layer gathers into a film, which binds the hydration reaction product in Together they form a complete network structure. The composite system formed by cement hydration and latex powder film formation can improve the dynamic cracking resistance of putty through the joint action.
The putty used as a transitional layer between external wall insulation and paint should not be stronger than plastering mortar, otherwise cracking will easily occur. In the whole insulation system, the flexibility of the putty should be higher than that of the base material. In this way, the putty can better adapt to the deformation of the substrate and buffer its own deformation under the action of external environmental factors, relieve stress concentration, and reduce the possibility of cracking and peeling of the coating.
Post time: Mar-06-2023