Polyvinyl Alcohol Powder PVA 2488 2688 1788 1799

Function and mechanism of Polyvinyl Alcohol Powder in putty

After dry mixing Polyvinyl Alcohol powder PVA with other powders, add water to form paste. After the water evaporates, a frame structure composed of inorganic and organic binders is formed, that is, a brittle and rigid framework composed of hydraulic materials, and a flexible connection of polyvinyl alcohol powder with a film structure on the solid surface. This connection can be imagined as a connection of many tiny springs on the rigid framework. Because the tensile strength of polymer resin film formed by polyvinyl alcohol is much higher than that of hydraulic materials by orders of magnitude, the strength of putty itself is enhanced, that is, the cohesion is improved. Because of the flexibility of polymer, the deformation capacity is much higher than that of rigid structure formed by hydraulic materials, etc., so that the deformation capacity of putty can be improved, and the role of stress dispersion can be greatly improved, thus improving the crack resistance of putty. The water resistance of polyvinyl alcohol powder is weaker than that of Redispersible Latex Powder. However, in the alkaline system of water-resistant putty containing cement, polyvinyl alcohol will be saponified by the alkali generated by the hydration of the putty, and absorbed by Shi Ying materials at the same time. The hydrophilic property of polyvinyl alcohol is greatly weakened, so it will not affect the water resistance of water-resistant putty.