Near infrared reflection spectroscopy: A versatile tool for rapid characterization of olefin copolymers and high-throughput experiments

Abstract

Near infrared (NIR) spectroscopy was developed as a rapid analytical method for the determination of the composition of olefin copolymers obtained in high-throughput screening. NIR spectra of ethene/propene and ethene/1-hexene copolymers, also characterized by means of 13C NMR spectroscopy, were recorded and used to design multivariate calibration models. Different methods for the preprocessing of the spectra, including the linearization by non-linear transformations, were compared. Optimal methods and error estimates were established using crossvalidation. This technique is of particular interest for the rapid on-line analysis of high-throughput experiments in the field of polymer and catalyst design employing methods from combinatorial chemistry.