Rheological measuring techniques and their relevance for the molecular characterization of polymers

摘要: Abstract The zero shear viscosity η0, the linear steady-state compliance and elongational are rheological quantities, which can preferably be used for a molecular characterization of polymers. techniques applied to obtain reliable results described. It is demonstrated that polyethylenes high-density fulfill relationship η0 ∼  M w 3.6 independently polydispersity. Mw absolute mass-average molar mass. Long-chain branched significantly deviate from this relation. characterize electron beam irradiated polypropylenes. clearly shown long-chain branches introduced by irradiation topography changes with dose. Measurements viscosities support conclusions experiments. Creep tests in extension show existence run through maximum as function rates reached at steady state. shape curves depends on dose indicating once more change structure irradiation.