Stability of Latex in Cement Paste: Experimental Study and Theoretical Analysis
To clarify the key factors affecting the stability of latex in cement paste, five latexes with varied hard and soft monomer contents were prepared, and the relationship between the stability of latex in cement paste and the amount of surfactant was investigated through flowability test and residue on sieve test. Besides, the amounts of surfactant required for covering the bare surface of polymer particles and the coefficient of restitution of polymer particles during collision process were calculated. Results show that the stability of latex in cement paste decreases with the increase of soft monomer content. Instead of the coverage ratio of surfactant on polymer particle, the coefficient of restitution of polymer particles determines the stability of latex in cement paste, and the higher coefficient of restitution contributes to the higher stability of latex in cement paste. These results provide some suggestions for the development of latex used for modification of cement-based materials.
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