Molecular weight‐intrinsic viscosity relationship and molecular weight distribution of low pressure polyethylenes

Abstract

Abstract Molecular weights of low pressure polyethylene fractions were measured by an ebulliometric method and an osmotic pressure method. The results can be correlated by an equation, [η] = 5.10 × 10 −4 M 0.725 , with the intrinsic viscosity measured at 130°C. in Tetralin, for a molecular weight greater than 3750. All three types of polymer fractions, Ziegler‐type low pressure polyethylene, Phillips low pressure polyethylene, and polymethylene from the decomposition of diazomethane, conform to the above correlation. The molecular weight distributions of two samples of Ziegler type polyethylene and one sample of Phillips' Marlex 50 were determined. All three distributions were found to be very broad and contained large amounts of low molecular weight materials.