Randomly-Branched Polymers by Size Exclusion Chromatography with Triple Detection: Computer Simulation Study for Estimating Errors in the Distributions of Molar Masses and Branching Degrees

Abstract

This article theoretically evaluates the biases introduced into the distributions of molar masses (MMD) and number of long chain branches per molecule (LCBD), when randomly branched polymers are analyzed by size exclusion chromatography (SEC) with molar mass sensitive detectors. The MMD of a polymer with tetrafunctional branch units is simulated under ideal SEC, i.e., Theta-solvent, perfect measurements, and perfect fractionation by hydrodynamic volume except for a minor mixing in the detector cells. A negligible bias is introduced into the MMD, even when including band broadening in the columns. In contrast, poor MMD estimates are obtained when the chromatograms are contaminated with additive noise. Only qualitative estimates of the LCBD are possible.