Obtaining and evaluation of polyethylene nanocomposites with graphene nanoplatelets through in-situ ethylene polymerization

In-situ polymerization of ethylene with graphene has been previously studied; however, the reported nanocomposites exhibit poor filler dispersion, even at low graphene loadings. In the present work, well dispersed and homogeneous graphene nanoplatelets (GNP)-high density polyethylene (HDPE) nanocomposites were obtained in up to 12.5% weight content of graphene through an in-situ polymerization of ethylene in graphene suspensions. The composites' potential as masterbatches was evaluated by melt mixing them with commercial HDPE. The obtained materials exhibited important physical-mechanical properties increases when compared with those of commercial HDPE. To our knowledge, our materials' GNP concentration (<= 0.82 wt.%) is the lowest reported, with the composites showing a 27% increase in their maximum tensile strength and a 41% increase in their flexural modulus when compared with blank HDPE. In addition, Raman spectroscopy and scanning electron microscope (SEM) analyses give evidence of the higher exfoliation degree of GNP obtained in the in-situ ethylene polymerizations.