Benzoxazine-functionalized multi-walled carbon nanotubes for preparation of electrically-conductive polybenzoxazines

Functionalization of multi-walled carbon nanotubes (MWCNTs) has been carried out using benzoxazine-containing compound (BPA-FBz) and polymer (PFBz) as modifiers through Diels–Alder reaction. The benzoxazine-functionalized MWCNTs (MWCNT-FBz and MWCNT-PFBz) have been characterized with Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analyzer, and high-resolution transmission electron microscopy. MWCNT-FBz and MWCNT-PFBz are thermally cross-linkable nanomaterials and could be fabricated with press molding and other thermal-forming processes. The cross-linked pellets of MWCNT-FBz and MWCNT-PFBz show surface electrical conductivities of 0.05 S cm−1. Moreover, nanocomposites have also been prepared from BPA-FBz and MWCNT-FBz. The nanocomposites have shown high electrical conductivities (about 7 × 10−5 S cm−1) and good mechanical strength. The attractive properties have been attributed to the good compatibility between the polybenzoxazine matrix and MWCNT-FBz, as the benzoxazine groups of MWCNT-FBz could copolymerize with BPA-FBz in the preparation of nanocomposites.