Polyacrylonitrile-MWCNT hybrids obtained by free radical polymerization in miniemulsions

Abstract

Polyacrylonitrile (PAN) and poly(acrylonitrile-co-vinylcarbazole) (PAN-VK) hybrids were obtained in presence of multiwalled carbon nanotubes (MWCNT) by a one-step free radical polymerization in miniemulsions. MWCNTs, in an unmodified state, as well as MWCNTs functionalized with maleic anhydride or monoethoxy dimethylvinyl silane, were used. The presence of MWCNT increased the molecular weights of the polymers and affected the polydispersity index. The polymers obtained next to the MWCNT showed a high value in their crystallinity index (33 %). The method was proven as an efficient route for dispersing nanotubes in the polymer matrix. Functionalized MWCNTs restrict the transfer reaction to areas next to the walls of the nanotubes during the polymerization and increase the dispersability in the final polymer matrix. MWCNT –polymer hybrids showed perspectives in membrane fabrication, as well as a specific profile, for carbon fibers precursors (with advantages in the three main stages: cyclization, dehydrogenation and decomposition).