Chapter 11 – Polyolefins

The discovery of olefin polymerization using the Ziegler-Natta catalyst, polyolefin has become one of the most important industrially produced polymers. In particular, polyethylene, polypropylene, and ethylene-propylene copolymers have been widely used as commercial products. High resolution solution nuclear magnetic resonance (NMR) has become the most powerful analytical method used to investigate the microstructures of these polymers. Tacticity and comonomer sequence distribution are important factors for determining the mechanical properties of these copolymers. Furthermore, information on polymer microstructures from the analysis of solution NMR has added to an understanding of the mechanism of polymerization. On the other hand, high resolution solid-state NMR has been available to analyze solid structures for approximately 20 years. This is a very powerful method to analyze the structures of solids, which can reveal conformation, crystallographic forms and the morphological character of solid without special sample preparations. It is expected that the information obtained from solid-state NMR will show how the mechanical properties of the solid arise.