Physical properties and dynamics of the amorphous phase for some polymers by NMR from the processing point of view

Abstract

This review presents the NMR parameters and physical properties of polymeric materials in terms of the structure and dynamics of the amorphous phase. Reactor powders of ultra-high molecular weight polyethylene do not show differences by X-ray diffraction or thermal measurements, but these differences can be clarified by NMR. With regard to the kneading of thermoplastic elastomers, the plasticisation behaviour of the matrix and the penetration of the matrix components into the cross-linked components could be clarified. Cyclodextrins and methylated cyclodextrins were identified as candidates for plasticisers for polylactic acid, enabling stretching. A measurement system that enables in-situ observation of the stretching process has been developed, revealing structural changes during melt stretching of polyethylene and polypropylene. The role of tie molecules in the stretching and shrinkage of polymer actuators was clarified.