Chain conformation basic principles

High-resolution NMR in the solid state of matter has been developed fairly recently. Since this technique can detect the local structure of molecules via chemical shift and magnetic relaxation, it has been possible to obtain detailed information on chain conformation as well as chain dynamics of macromolecules not only in the crystalline state but also in the non-crystalline, glassy or rubbery state. This chapter gives a brief description of the basic principles of solid-state high-resolution NMR as well as its recent application to crystalline polymers. 

Electrically conductive polymer nanocomposites are widely used especially due to their superior properties and competitive prices. It is expected that as the level of control of the overall morphology and associated properties increases we will see an even wider commercialisation on traditional and totally novel applications. In this section we have discussed the basic principles of the percolation theory and the different types of conduction mechanisms, outlined some of the critical parameters of controlling primarily the electrical performance and we have provided some indications on the effect such conductive fillers have on the overall morphology and crystallisation of the nanocomposite. The latter becomes even more critical if we take into consideration that modem nanosized fillers offer unique potential for superior properties at low loadings (low percolation thresholds) but have a more direct impact on the morphology of the system. Furthermore we have indicated that similar systems can have totally different behaviour as the preparation methods, the chain conformation and the surface chemistry of the fillers will have a massive... 

The conformation assumed by polymer chains in the crystalline state depends on the configuration of the stereoisomeric centers present along the chains, and is defined by two basic principles [1,2,23-25]. 

Starting from an analysis of the conformation of a polymer chain in the liquid (amorphous) and crystalline (ordered) states, it has been possible to develop the basic thermodynamic, kinetic, and stmctural principles that govern the crystallization... 

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