Determination of molecular dimensions of linear polyethylene by light scattering

Multidimensional high‐temperature liquid chromatography: A new technique to characterize the chemical heterogeneity of Ziegler‐Natta‐based bimodal HDPE

“…Because of the extreme stability of the carbon stationary phase and the fact that the low molar mass samples are not affected it is highly improbable that this is the result of structural changes in the stationary phase, as this was the case for some silica gel column packings 32. A plausible explanation is provided when considering the state of the macromolecules in solution: according to Helmstedt et al,33 PE is in 1‐decanol at 140°C at θ‐conditions, which means that the polymer coils are in an unperturbed state. Using the reported data33 about the molecular dimensions of PE at these conditions, a relation between the unperturbed root‐mean‐square end‐to‐end distance of linear PE ( $\langle{h}^2_0\rangle^{1/2}$ ) and the elution volume at peak maximum of PE standards can be constructed (Figure 3).…”

“…A plausible explanation is provided when considering the state of the macromolecules in solution: according to Helmstedt et al,33 PE is in 1‐decanol at 140°C at θ‐conditions, which means that the polymer coils are in an unperturbed state. Using the reported data33 about the molecular dimensions of PE at these conditions, a relation between the unperturbed root‐mean‐square end‐to‐end distance of linear PE ( $\langle{h}^2_0\rangle^{1/2}$ ) and the elution volume at peak maximum of PE standards can be constructed (Figure 3). …”

Cloud Point Temperature Measurements on Polyolefins: Identification of Potential New Mobile Phases for Interactive Liquid Chromatography of Polyolefins

“…Relation between the θ temperature for PE and the corresponding T CP in several solvents. The line serves as a guide for the eye.…”