Preparation and crystallization of isotactic polypropylene composites filled by titanium dioxide-supported montmorillonite with a β-nucleating surface

To obtain multi-functional beta-iPP composites, beta-iPP composites are always filled by multiple fillers with alpha-nucleating ability. To prepare beta-iPP/TiO2/MMT composites, TiO2-supported MMT with a beta-nucleating surface was prepared through hydrolysis reaction of Tetra-n-butyl titanate and chemical reaction between pimelic acid and calcium ion. X-ray diffraction and scanning electron micrograph confirmed the formation of TiO2 on the surface of MMT. The differential scanning calorimeter and X-ray diffraction illustrated that the beta-iPP composites filled by TiO2 and MMT had lower relative beta-phase contents than beta-iPP. It is observed by polarized optical microscope that addition of TiO2-supported MMT with a beta-nucleating surface into iPP can increase the spherulite nuclei density and decrease the spherulite size significantly and obtain the beta-iPP/TiO2/MMT composites with high relative beta-phase content.