The Function and Mechanism of Polyvinyl Alcohol Powder in Putty
After the PVA powder is mixed with other powders, the paste slurry is formed by adding water. After evaporation, the structure of inorganic and organic binder is formed, the brittle rigid skeleton of the water rigid material, and the flexible and ductile connection of the PVA powder in the gap and the film structure of the solid surface, this connection can be imagined by a lot of small spring connected to the rigid skeleton, because the polyvinyl alcohol formation of polymer resin film tensile strength is far higher than the number of water rigid materials, so that the strength of the putty can be enhanced, that is, cohesion can be improved.
Because of the flexibility of the polymer, the deformation ability is much higher than the rigid structure formed by the water rigid material, so it can improve the deformation ability of the putty, the effect of the dispersing stress is improved greatly, and the crack resistance of the putty is improved. The water resistance of polyvinyl alcohol powder can be weaker than that of dispersible latex powder. But in the cement-containing putty alkaline system, polyvinyl alcohol will be putty in the cement produced by the alkali saponification, at the same time by the absorption of quartz materials, polyvinyl alcohol hydrophilic can be greatly weakened, so it will not affect the water resistance of waterproof putty performance.