Applied Catalysis A: General, Vol.580, 149-157, 2019
Modification of rGO by B(C6F5)(3) to generated single-site Lewis Acid rGO-O-B(C6F5)(2) as co activator of nickel complex, to produce highly disperse rGO-PE nanocomposite
We investigated the incorporation of reduced graphene oxide (rGO) into branched polyethylene, achieving nanocomposites with different rGO contents. The strategy included the direct reaction between B(C6F5)(3) (BCF) with rGO (reduced graphene oxide) and demonstrated by XPS, B-11, F-1(9) -MAS NMR, FT-IR the efficient modification of the rGO. The resulting solid contains sites -O-B(C6F5)(2 )capable of acting as co-catalysts in the activation of an (alpha-iminocarboxamidate)nickel (II) complex. The results show the efficient activation of this nickel catalyst through an exocyclic Lewis acid-base interaction and the subsequent ethylene polymerization. We achieved with this heterogeneous catalytic system activity greater than those previously reported for the BCF-Ni, homogenous system, while the characterization of the black colored polymer generated in situ, showed a complete delamination of the rGO. It became the first rGO-B(C6F5)(2) -Ni system fully characterized and capable of delaminate the rGO support by producing a nanocomposite rGO-LLDPE without loss of activity, compared to the homogeneous system. In addition, the polymer contains about 70% of methyl branches and a melting point higher than 125 degrees C.
Keywords:rGO-PE nanocomposite;rGO-Bis (pentafluorophenyl) borane;In situ activation;Nickel catalysis;Olefin polymerization;Remote activation