Synthesis and dispersion mechanism of AH polymers on cement particles

Abstract

The water-soluble hydroxyl carboxyl sulfonated aminophenol (AH) polymers were synthesised by the reaction between phenol, soldium sulfanilate, salicylic acid and formaldehyde. The effect of monomer ratios, pH value, reaction time and temperature on the dispersing properties of cement particles was analysed, the optimum reaction conditions were investigated. The molecular structure of AH polymers was characterised by infrared spectroscopy and gel permeation chromatography. A study was made of the surface properties of cement particles with AH polymers, such as surface tension, foaming properties and ξ-potential. The test results show that the surface tension of the solution decreases as AH polymers and aminosulfonate phenol formaldehyde condensate (AS) superplasticiser concentration increases. The solution with AH polymers has a lower surface tension than the solution with AS superplasticiser at the same concentration. The foaming capacity of AH polymers and AS superplasticiser, however, has a better foam stability than the solution with AS superplasticiser. The ξ-potential of cement particles with AH, AS polymers and AS superplasticiser increase as AH polymers and AS superplasticiser concentration and time are increased. The excellent dispersing properties of AH polymers on cement particles are attributed to the combination effect of adsorbing lubricate, electrostatic repulsive force and steric hindrance.