Synthesis, characterization and crystallization kinetics of nanocomposites prepared by in situ polymerization of ethylene and graphene

High-density polyethylene (HDPE)/graphene nanocomposites were synthesized by in situ polymerization. Zriconocene was used as a catalyst and methylaluminoxane as a co-catalyst. The effect of graphene on the activity of the catalyst and on chain microstructure, crystallization kinetics, mechanical and thermal characteristics of HDPE was investigated. Both the thermal and mechanical properties of HDPE were enhanced. The catalyst showed a slight reduction in the activity. The molecular weight of the polymer was analyzed by gel permeation chromatography, and a significant increase in weight-average molecular weight (M (W)) of HDPE was observed in the presence of graphene. Isothermal crystallization kinetics was studied by differential scanning calorimetry. The crystallization rate was increased with the addition of graphene. Microcalorimetric analysis indicated a major decrease in the peak decomposition temperature as well as the total heat released for the HDPE/graphene nanocomposites.