The additive is a generic term for a few materials which could change some properties of mortar, such as redispersible polymer powders (or emulsion), fibers, retarding agents, fluidizing agents, deformation agents for adjusting the volume of mortar, and water-repellent agents. The special performance that additives give dry-mixed mortar is the key to distinguish it from.. read more →

The glass-transition temperature refers to the temperature at which polymers will be converted from an elastic state to a glassy state, expressed by Tg. When the temperature is higher than Tg, the material is rubber-like in behavior and generates the elastic deformation under load; when the temperature is lower than Tg, the material is glass-like.. read more →

The minimum film-forming temperature refers to the minimum temperature at which polymers form a continuous film, expressed by MFT. If the cement hydration temperature is below this value, the energy supplied will not be enough to start film formation. At this time polymers will be present in the form of intermittent particles in the cement.. read more →

The roles that redispersible polymer powder plays in mortar can be considered as follows. First, after water added into mortar, the powder particles will get dispersed in water and quickly form a film under the action of hydrophilic protective colloid and mechanical shear force, causing an increase in the air content of mortar and helping.. read more →

The common varieties of redispersible polymer powder currently on the market are ethylene vinyl acetate copolymer (EVA), ethylene/vinyl chloride/vinyl laurate terpolymer (E/VC/VL), vinyl acetate/ethylene/vinyl ester of versatic acid terpolymer(VAC/E/VeoVa), vinyl acetate/vinyl ester of versatic acid terpolymer copolymer (VAc/VeoVa), acrylate/ copolymer (A/S), vinyl acetate/ acrylate/ vinyl ester of versatic acid terpolymer copolymer (VAC/A/VeoVa), polyvinyl acetate  polymer.. read more →

The redispersible powder is a special water-based emulsion made by spray drying and a polymer binder prepared mainly based on the vinyl acetate-ethylene copolymer. After partial evaporation of water, polymer particles form a layer of polymer film by agglomeration and play the role of adhesive. When redispersible polymer powder is used together with inorganic cementitious.. read more →

After redispersible polymer powder is added into cement mortar, the tensile strength and flexural strength of mortar will be significantly improved, while the compressive strength won’t get significantly improved, even declined. The reason is that the toughening effect of redispersible polymer powder has enhanced the internal tensile strength of mortar and the bonding tensile strength.. read more →

After dry-mixed mortar added with redispersible polymer powder is mixed with water, the modification of redispersible polymer powder on cement mortar is accomplished by redispersion of powder, hydration of cement and film formation of polymer. The film forming process of redispersible latex powder in mortar can be divided into three stages.   In Stage One,.. read more →

Redispersible polymer powders are polymer emulsions which have been converted by a series of process such as high temperatures and pressures, spray drying and surface treatment to powdered thermoplastic resin materials. When mixed with water, these powdered organic binders can redisperse in water back into new emulsions with essentially identical properties to the original copolymer.. read more →

The production of redispersible polymer powder is mainly divided into two steps, namely, emulsion polymerization and drying, as shown in the figure. (l) Emulsion Polymerization Monomers adopted for emulsion polymerization determine the types of redispersible polymer powder. Polymer monomers used for the production of redispersible polymer powder are mainly olefins and unsaturated monomers, including a.. read more →