Calcium stearate modified nano-CaCO3 (CaSt-nano-CaCO3) was prepared

and iPP /calcium stearate modified nano-CaCO3 (iPP/CaSt-nano-CaCO3) was prepared by melt blending iPP with CaSt-nano-CaCO3 particles.Compared with pure iPP

the addition of CaSt-nano-CaCO3and nano-CaCO3particles both increased flexural strength and flexural modulus of iPP

and impact strength was also improved in these two series composites.In comparison with iPP/nano-CaCO3

the impact toughness of iPP/CaSt-nano-CaCO3composites was improved slightly

while the flexural modulus of iPP/CaSt-nano-CaCO3was obviously increased.Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) tests showed that with increasing CaSt-nano-CaCO3content

the crystallization temperature and the nucleating ability of the composites were all increased.The crystallization temperature of iPP/CaSt-nano-CaCO3is lower than that of iPP/nano-CaCO3 with the same filler content

indicating that the nucleating ability of CaSt-nano-CaCO3is weaker than that of nano-CaCO3 in iPP matrix.Wide-angle X-ray diffraction (WAXD) results showed the composites did not exhibit crystal form after addition of nano-CaCO3and CaSt-nano-CaCO3 particles.Compared with iPP/nano-CaCO3

the presence of calcium stearate increases the melt flow rate (MFR) of iPP composite with the same filler content

implying that the processability of the composites will be improved with the modification of nano-CaCO3 with calcium stearate.