Article: Streamlining PET Viscosity Measurement Using an Automated Differential Viscometer

By Alba Cárdenas, Alberto Ortín, Pilar del Hierro, (Polymer Char).  

Streamlining PET Viscosity Measurement using an automated differential viscometer.

Published on LCGC International

Abstract

The determination of dilute solution viscosity is crucial in the polyethylene terephthalate (PET) industry due to its correlation to the polymer’s molecular weight, which determines its macroscopic properties and classification according to application grades. Historically, this test has been performed using manual glass capillary viscometers (Ubbelohde or suspended-level viscometers) measuring the drop times of the solvent and the polymer solution. In this work, a new fully automated method is applied to PET viscosity determination based on a two-capillary differential viscometer. The precision of this new automated method is tested with virgin and recycled PET with different ranges of viscosity and crystallinity.