Material BehaviourEffect of branching characteristics of ethylene/1-butene copolymers on melt flow index

Five different samples of ethylene/1-butene copolymers with relatively similar weight average molecular weight and molecular weight distribution, but different branching characteristics, were investigated. The co-monomer content of the samples was measured by 13C NMR technique. Then, the samples were fractionated by a step-wise crystallization method in DSC and the relative amount of each fraction was compared between the samples. By measuring the Melt Flow Index (MFI) of the samples, a qualitative relationship between the branching structure and MFI of the samples is proposed.