POLYMERS CONTAMINATED BY MINORITY CONSTITUENTS: A METHOD FOR CORRECTING THE MOLAR MASSES DETERMINED BY SEC/DR

CLEMENTI, LUIS A.; VEGA, JORGE R.; MEIRA, GREGORIO R.; BEREK, DUSAN

Porto de Galinhas

Simposio; XIV Simposio Lationoamericano de Polymeros; 2014

Brazilian Polymer Association

A numerical method is proposed for estimating the molar mass distribution (MMD) of a polymer contaminated by a minority constituent, when the sample is measured by size exclusion chromatography with a differential refractometer (SEC/DR). The method involves three main steps: 1) the detection of a minor contaminating fraction on the basis of the second derivative of the smoothed DR chromatogram, 2) the approximation of the DR chromatogram with a combination of previously-defined analytical functions, and 3) the calculation of the MMD of each constituent identified in the previous step. The estimation method is evaluated on the basis of experimental examples analyzed with column sets of different resolutions and effective fractionation ranges.