FTIR‐ATR study of interactions in polymer blends containing polyesterurethane

Abstract

AbstractMolecular interactions such as especially hydrogen bondings are considered to play a key role in polymer compatibility. In this study binary blends produced by extrusion of a MDI based segmented polyesterurethane (TPU) together with styrene‐acrylonitrile and acrylonitrile‐butadiene‐styrene copolymers, respectively, could be investigated without additional sample preparation using the infrared spectroscopic sampling technique of attenuated total reflection (ATR). With increasing content of the nitrile group containing polymers in the blends urethane carbonyl groups completely hydrogen bonded in the pure TPU are liberated. “Free” NH groups, however, are not detectable in the NH stretching region of the ATR spectra of the blends. The interpretation of the obtained spectral effects occurring in the blends is supported by experiments with N‐butyl‐carbamideacid‐methylester as model compound with an urethane linkage. The presented results lead to the conclusion, that intermolecular hydrogen bonding involving urethane NH groups and nitrile groups of the other polymers in the blends has been arised. Quantitative differences of these interactions between the two kinds of blends investigated in this study are discussed.