Combined quantitative NMR imaging and relaxometry on polymer materials: a fundamental study of rubbers and water uptake in polyamide 46

Abstract

Introduction excerpt: As the demand for high-performance materials increases, so does the need for an analytical method, which can provide spatially localized information on the internal structure of the substance. This is necessary since a polymer material can be microscopically heterogeneous for example due to processing and which can influence the material properties such as strength, toughness, elasticity, … Magnetic resonance imaging (MRI), first proposed by Lauterbur in 1973,1 has proven to be a superior technique to characterize the materials’ interior and to obtain more information on the local molecular dynamics. It is a unique, nondestructive and non-invasive technique, which does not require the use of ionizing radiation and enables one to obtain a three-dimensional reconstruction of the studied specimen. The different chemical components in a sample can be visualized individually by applying chemical shift selective MRI. By adjusting the experimental conditions, it is possible to manipulate the image contrast and to use the different relaxation parameters to emphasize local differences in molecular chain mobility. In the modern micro-MRI, where only objects of a few centimeters are studied, a resolution of ± 10 µm is attainable.