Modification of polypropylene with composite nucleating agents containing 2, 2-methylene-bis-(4, 6-di-t-butylphenylene) phosphate/attapulgite/silica nano-particles

A series of composite nucleating agents based on inorganic nano-particles (attapulgite and/or silica) and organic phosphate nucleating agent (NA11) were prepared via spray drying technique. The effects of nucleating agents on the mechanical properties and nucleation behavior of PP were studied. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), polarizing optical microscopy (POM) and wide angle X-ray diffraction (WAXD) were employed to characterize the dispersion of composite nucleating agents and their effects on the crystallization behavior of polypropylene. The mechanism of influences of composite nucleating agents on the properties of PP was also discussed. The research results suggested that the mechanical properties of PP were improved substantially with addition of composite nucleating agents into the system. The stiffness of PP was increased significantly with increasing the loading of composite nucleating agents. The ternary composite nucleating agents showed significant effect on improving the stiffness of PP at a loading of 0.2 wt%.which was similar as using pure NA11 at such loading. The observation on microscopic morphology showed that the three components in the ternary composite nucleating agent were inter-partitioned with each other, resulting in the improved dispersion of NA11 and the inorganic nano-particles in PP matrix.