In situ polymerization of ethylene in the presence of graphene by α‐diimine Nickel (II)/MAO catalyst system: Thermal and rheological study

Abstract

In situ polymerization of ethylene with pretreated graphene nano‐platelet (GNP) was carried out by (α‐diimine nickel)/MAO catalyst system. The molecular weight of the synthesized samples was determined using rheometric mechanical spectroscopy. The number of branches and melting temperature values was evaluated by regular differential scanning calorimetry (DSC) and successive self‐nucleation and annealing (SSA) technique. According to obtained results, the molecular weight of the samples was increased from 72,730 to 260,100 g/mol for neat PE and high‐filled GNP, respectively. The number of chain branches decreased by the addition of GNP from 61.51 per 1,000 carbon atoms to 37.10 for neat PE and the sample containing 22.36 wt% of GNP. Obtained results revealed that the samples containing low branches and high molecular weight were achieved in the presence of highly loaded GNP. Also, the electrical conductivity, storage modulus, loss modulus, and complex viscosity of the samples improved by increasing GNP weight fraction.