Determination of Polyolefin branching structure and molecular weight by High Temperature Gel Permeation Chromatography (GPC/SEC)

Viscotek, a Malvern Instruments group company, has announced a new technical article that describes and illustrates how High Temperature GPC/SEC offers scientists a breakthrough technique for determining the molecular weight and branching structure of polyolefins.

Polyethylene and polypropylene are examples of polyolefins used in large amounts throughout the industrialised world. Depending on the process and catalyst used in the manufacturing process either linear or branched polyolefins can be produced. In case of polyethylene there are at least three polymer types: HDPE (High Density Polytheylene), LDPE (Low Density Polyethylene) and LLDPE (Linear Low Density Polytehylene). The article describes how the Viscotek Model 350 High Temperature GPC/SEC-System was used to determine molecular weight distribution and branching structure of a range of polyethylene samples thereby determining the polymer type and likely properties.

The Viscotek Model 350 HT-GPC system provides absolute molecular weight without extrapolation or correction, molecular size, and intrinsic viscosity, as well as information on branching, structure and aggregation in a single GPC/SEC experiment. Representing a breakthrough in high temperature technology, the Model 350 system includes a High Temperature Triple Detector Array (HT-TDA), with an automated sample preparation & delivery system and OmniSEC GPC software for complete system control, data acquisition and processing. The Viscotek Model 350 HT-TDA combines low angle light scattering with viscometry and concentration for complete and comprehensive macromolecular characterisation. All detectors reside within a temperature-controlled oven compartment which has space for the analytical GPC columns.

Malvern Instruments acquired Viscotek in January 2008.