Molmassenverteilung und lösungszustand von linearen polyethylenen, 1. Lichtstreuungs-, viskositäts- und GPC-messungen

Light scattering, viscosity and GPC measurements were performed on a homologous series of linear polyethylenes with viscosity average molar masses in decahydronaphthalene at 135°C between 1,0 · 10⁵ and 2,7 · 10⁶ g · mol^?1 and relatively broad molar mass distributions. 1,2,4-Trichlorobenzene, α-chloronaphthalene, decahydronaphthalene (decalin) and decane were used as solvents. In the case of linear polyethylene in decahydronaphthalene and decane relationships between intrinsic viscosity and weight average molar mass were established. The values of the weight average molar masses obtained by light scattering are considerably higher than those obtained by viscosity and GPC measurements. These discrepancies are explained by molecular aggregation of the polyethylene macromolecules.