In-situ generation of a well-dispersed multiwall carbon nanotube/syndiotactic polystyrene composite using pentamethylcyclopentadienyltitanium trimethoxide anchored to multiwall carbon nanotubes

A well-dispersed multiwall carbon nanotube (MWCNT)/syndiotactic polystyrene (sPS) composite was prepared by simple in-situ polymerization of styrene using pentamethylcyclopentadienyltitanium(IV) trimethoxide (Cp*Ti(OMe)3) attached to the shortened and functionalized MWCNT (f-MWCNT). The attachment of Cp*Ti(OMe)3 to the f-MWCNT was confirmed by thermogravimetric analysis, X-ray photoelectron spectroscopy, Fourier transformed infrared spectroscopy, and energy dispersive X-ray spectroscopy. Cp*Ti(OMe)3 attached to pristine MWCNT in the presence of methylaluminoxane (MAO) did not produce PS, whereas Cp*Ti(OMe)3 attached to f-MWCNT showed a high catalytic activity for the syndiospecific polymerization of styrene under the same polymerization conditions. Obtained sPS showed a narrow molecular weight distribution (PDI ≈ 2), a high SI value (≥90%), and a high melting point (≈272 °C). Scanning electron microscopy and transmission electron microscopy images showed that MWCNT strands were well dispersed in the MWCNT/sPS composite. Such composites had greatly improved thermal stability compared to normal sPS polymers.