Modification of isotactic polypropylene by silica nanocapsules via melt blending method

Isotactic polypropylene (iPP) fibers containing silica nanocapsules (described as SNCs) were prepared with twin‐screw extruder. Modification of silica nanocapsules was hydrolyzed with octadecyltrimethoxysilane in order to improve the interaction between capsules and the hydrophobic PP matrix. Characterization of iPP/SNCs blends were performed by transmission electron microscopy, field‐emission scanning electron microscopy (FE‐SEM), differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, and tensile strength tests. Dispersion quality of silica nanocapsules was examined using FE‐SEM. As a result, the modified silica nanocapsules with octadecyltrimethoxysilane (SNCs‐C 18 ) could be well dispersed into iPP matrix because of the hydrophobic surface of modified capsules. The incorporation of all the SNCs samples showed little influence on the crystallization behavior, thermal stability of iPP and mechanical properties. By contrast, the presence of unmodified SNCs in iPP showed a negative effect on mechanical properties due to the poor interface interaction between the inorganic and organic phases. This study presented a successful potential applied for encapsulation. POLYM. COMPOS., 39:762–769, 2018.