Fabrication and characterization of a novel hydrophobic CaCO3 grafted by hydroxylated poly(vinyl chloride) chains

The hydroxylated PVC (PVC-OH) was successfully synthesized by a suspension polymerization of vinyl chloride (VC), butyl acrylate (BA) and hydroxyethyl acrylate (HEA). Novel hydrophobic CaCO 3 was then prepared by a urethane formation reaction between methylene diphenyl diisocyanate (MDI) and the OH groups both in the PVC-OH chains and on the surface of pristine CaCO 3 particles. The effect of the PVC-OH content on the grafting ratio of treated CaCO 3 particles was extensively investigated. Combining the result of Fourier transform infrared (FTIR) with that of water contact angle, it can be concluded that the hydrophobicity of CaCO 3 had been efficiently improved by the PVC-OH segments grafted on the surface of CaCO 3 particles. X-ray diffraction (XRD), thermal gravity analysis (TGA), scanning electron microscope (SEM) and transmission electron microscope (TEM) were also used to study crystalline behaviors, thermal stability and surface morphology of the modified CaCO 3 particles, respectively. The change of specific surface area implying surface modification was investigated as well.