Motional phase disorder of polymer chains as crystallized to hexagonal lattices

A review. Chain-dynamics of flexible synthetic macromols. in the cryst. state has been clarified by multinuclear solid-state NMR observations. Massive motional phenomena are shown when chains are crystd. in the hexagonal phase. Several examples have been surveyed, where motion is induced by high temp. and pressure or favored by inclusion of moderate amts. of comonomer units in the main chain and by the use of monomers contg. mobile side chains. Also, motional phenomena of fast spinning and large librations of the macromols. are promoted when the isolated chains are confined to nanochannels formed in hexagonal crystal structures of suitable matrixes. The motional behavior can be modulated by the topol. and the interactions in the unusual environments. This knowledge provides information about polymers in close contact with heterogeneous interfaces, such as polymers in nanocomposites or at surfaces.