Estimation of the Molecular Weight between Crosslinks of Crosslinked Semicrystalline Polyolefins

The molecular weight between crosslinks (MXL) of crosslinked semicrystalline polyolefins, polyethylene in particular, has been estimated from uniaxial tensile tests in the melt state with the Sentmanat Extensional Rheometer (SER). Applying the Mooney–Rivlin equation to these stress‐strain data resulted in the determination of an apparent molecular weight between crosslinks. This fast and convenient technique correlates well with the conventional approach where MXL is obtained via the plateau modulus from shear viscosity.