High impact strength of polypropylene composites with complex titanate whiskers/multiwalled carbon nanotubes

Isotactic polypropylene (PP) composites achieved high impact strength by melt mixing with complex titanate whiskers/multiwalled carbon nanotubes (MWCNTs). The complex fillers, obtained via coupling agent γ-aminopropyl triethoxysilane, triggered additional reinforcement with stiff backup of whiskers and strengthened interfacial adhesion generated from MWCNTs, forwarding positive synergy on the PP composites. In presence of compatibilizer maleic anhydride-grafted polypropylene, 5 wt% of the complex fillers brought about impact strength 6.3 ± 0.3 kJ/m2 to the composite, which was 103% higher than PP. Meanwhile, tensile strength was also improved with 34.8 ± 0.5 MPa as compared with that of PP (32.6 ± 0.3 MPa). Morphology witnessed by scanning electron microscope revealed that the complex fillers favored dispersion of MWCNTs in polymer matrix, fulfilling bridging for reinforcement. Detection of differential scanning calorimetry also indicated that the complex fillers facilitated crystallization of PP in the composites. Upon high impact strength and improved tensile property, the PP composites could find potentials with facile processing manipulation in applications.