Polyolefin Characterization in Xylene by High-Temperature Gel Permeation Chromatography with a New Evaporative Light Scattering Detector

Abstract

The advances in nebulizer technology of the evaporative light scattering detector (ELSD) for high temperature gel permeation chromatography (GPC) allowing lower operation temperatures, overcome the limitations of the differential refractive index (DRI) and infrared (IR) detectors, thus allowing xylene as solvent for evaluation of the molecular weight distributions (MWD) of polyolefins. Different types of polyolefins, previously characterized by GPC in trichlorobenzene (TCB) with a DRI detector, in an interlaboratory study conducted by International Union of Pure and Applied Chemistry (IUPAC) (Luruli, Phase 1: IUPAC SEC/GPC round robin project report: repeatability and reproducibility of sample preparation and analysis in high-temperature SEC, http://media.iupac.org/projects/2005/2005-011-3-400_rpt-phase1_110510.pdf , 2010), and also in a recent study by GPC in TCB with an ELSD and DRI (Boborodea and O’Donohue, Int J Polym Anal Charact 22:631–638, 2017), were for the first time analyzed by GPC with ELSD in xylene. In this solvent, the power exponent, governing the non-linear correlation between the ELSD signal and concentration, was found to be 1.40. After linearization of the ELSD signal, the measured average molecular weights of polyolefins in xylene were in good agreement with the values given by DRI detector in TCB. The molecular weight distributions obtained in xylene with an evaporative light scattering detector are similar with those evaluated by classical GPC with differential refractive index detector in TCB.