The Viscotek HT-GPC (high-temperature gel permeation chromatography) system from Malvern Instruments requires no user interventions, for simple filtering.
According to Malvern, it is also specified for safe, routine operation at the high temperatures necessary for analysing polyethylene and polypropylene.
It measures absolute molecular weight, molecular weight distribution, and polymer chain branching in a single experiment.
Malvern claims these are critical parameters for polyolefins that influence in-use properties such as strength and permeability.
Although GPC is a well-established and valued technique for polymer analysis, its use with polyolefins is hampered by their sparing solubility in so many solvents.
High-temperature operation is essential, increasing the risks associated with hazardous solvent use.
Fully automated and offering temperature control up to 160C, the HT-GPC is designed to be safe, accurate and productive.
With GPC the detectors used to characterise the sample, as it elutes from the separation column, dictate what information is gathered during each experiment.
The full Viscotek HT-GPC triple detector configuration includes refractive index (RI), viscometry and low-angle light scattering (LALS) detection.
Together, these detectors provide absolute molecular weight without extrapolation or correction, molecular size, intrinsic viscosity and branching information.
Three alternative detector configurations are available: RI alone; RI and LALS; and RI and viscometer.
The Viscotek HT-GPC has a modular design designed to enhance flexibility, reliability and ease of maintenance.
All configurations use the Vortex autoprep/autosampler for sample preparation and delivery.
This unit comprises an integrated autosampling device and heated mulitvial stirrer that dissolves and automatically injects the sample, eliminating the need for manual hot sample transfer.
The system is driven by Omnisec, which has full polymer branching calculations capability and a Branching View function that simplifies the study of long chain branching.
