Effect of molecular structure on dynamic mechanical properties of polyethylene obtained with nickel–diimine catalysts

摘要: Abstract Polyethylene made with a nickel–diimine catalyst was studied in order to understand the relationship between molecular structure and dynamic mechanical properties. Different branch lengths, from methyl longer, their contents these ethylene homopolymers, dramatically affects crystallinity of polyethylene samples, as shown by differential scanning calorimetry (DSC) crystallization analysis fractionation (CRYSTAF). T m CRYSTAF profiles are related not only content but also distribution on chain. The thermal showed three different groups materials, where stiffness varies according short-chain branching (SCB) content. Polyethylenes high SCB strong β-transition (tan  δ >1) despite lack any detectable crystallinity.