Mechano-activated surface modification ofcalcium carbonate in wet stirred mill and its properties
(1. School of Materials Science and Engineering, China University of Geosciences(Beijing), Beijing 100083, China; 2. School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China )
Abstract: Surface modification of calcium carbonate particles using sodium stearate(SDS) as a modification agent incorporated with the simultaneous wet ultra-fine grinding in the laboratory stirred mill was investigated. The physical properties and application properties of modified calcium carbonate were measured and evaluated. The action mechanism between SDS and calcium carbonate in the modification was studied by infrared spectrometry(IR) and X-ray photoelectron energy spectroscopy(XPS). The results indicate that the crushing mechanic force intensity can obviously influence the modification effect of calcium carbonate because of mechano-chemical effect. The hydrophilic surface of calcium carbonate is turned into hydrophobic after modification. The properties of polyethylene(PE) filled by modified calcium carbonate powder is markedly improved. And the adsorption of SDS could occur by chemical reaction with calcium carbonate surface.
Key words: surface modification; calcium carbonate; mechano-chemical effect; action mechanism