Preparation of shish-kebab and nanofiber polyethylene with chromium/Santa Barbara amorphous silica-15 catalysts



Cr/SBA-15 catalysts were prepared by the grafting of chromium nitrate nonahydrate [Cr(NO3)3·9H2O] complexes onto SBA-15 mesoporous materials. Shish-kebab and nanofiber polyethylenes (PEs) were prepared under different temperatures via ethylene extrusion polymerization with the Cr(NO3)3·9H2O catalytic system. The diameter of a single nanofiber was 100–250 nm. Scanning electron microscopy images showed that the polymer obtained from the SBA-15-supported catalyst under different polymerization temperatures produced nanofiber and/or shish-kebab morphologies. X-ray diffraction and differential scanning calorimetry were used to characterize microstructures of the materials. Polymers obtained with all of the catalysts showed a melting temperature, bulk density, and high load melt index; this indicated the formation of linear high-density PE. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010