Preparation of Polyacrylamide Emulsion Modified Waterproof Desulfurization Building Gypsum

In this paper the waterproofness of desulfurization building gypsum had been improved by polyacrylamide(PAM) emulsion. The effect of dosage and molecular weight of PAM emulsion on the physical mechanical properties and waterproofness have been investigated and XRD, SEM have been employed to determine the phase compositions of the material. The results showed that softening coefficient of desulfurization building gypsum increased from 0.34 to 0.69, the compressive strength after soaking in water for 24 h increased from 4.9MPa to 6.1 MPa. The effect of PAM emulsion modification prepared by PAM with molecular 3 million weight of on desulfurization building gypsum are better than with molecular weight of 5 million. The effect mechanism of PAM on desulfurization building gypsum was that PAM reacts with the Ca2+ cations produced desulfurization building gypsum hydration to form the ionic compounds acting as a filler and reinforcement in the porosity of desulfurization building gypsum, and also PAM covered the surface of desulfurization building gypsum particles to prevent the crystallization of CaSO4.2H2O.