Abstract：In order to the improve compatibility between hydromagenesite(4MgCO₃·Mg(OH)₂·4H₂O) and polymer materials, the hydromagnesite powders was modified with stearic acid, the effects of the amount of modifier on the BET specific surface area,oil absorption value, particle size, dispersion and sedimentation properties of hydromagnesite powders were researched, the hydromagnesite before and after modification were also characterized by FTIR. The results show that when the amount of stearic acid is 2.5%, the BET specific surface area, oil absorption value, d₅₀ and d₉₇of hydromagnesite powders are 9.049 m²/g,2.425 m L/g, 4.58 μm and 7.96 μm, respectively, and its dispersion property in the organic phase is improve obviously, and IR spectrum illustrates that the stearic acid is adsorbed on the surface of hydromagnesite powders.

Keywords: hydromagnesite; surface modification; stearic acid