Presented at ACS (American Chemical Society), 2011. Santa Rosa, CA, USA.
Alberto Ortín, Jesús Montesinos, Pilar del Hierro, Benjamín Monrabal. Polymer Char, Valencia, Spain.
GPC / SEC analysis of polyolefins, performed at high temperature to dissolve the polymer, is a dedicated and demanding task in both sample preparation and analysis.
Significant efforts in engineering have been done in recent years to bring high temperature GPC analysis to a modern, reliable, and automated task. The use of Infrared detector provided a stable baseline for concentration analysis with the capability of performing composition – molar mass interdependence analysis simultaneously.
New developments in Infrared detection have allowed the design of an integrated IR detector with ten times more sensitivity over the existing IR4 detector of the GPC-IR instrument. This development allows for the use of lower sample concentrations (required very often to prevent viscous fingering effects in the analysis of high molar mass resins) and provides better sensitivity to measure low levels of branch content simultaneously (pipe resins).
The new detector uses a Mercury Cadmium Telluride sensor (a modified integrated version of the well known IR5 MCT detector) that is thermoelectrically cooled and has been integrated into the existing GPC-IR instrument without demanding external blocks or heating interfaces.