Heterogeneity in polymers as studied by nuclear magnetic resonance

Abstract

A knowledge of the extent to which polymers are heterogeneous is fundamental to a full understanding of their properties. This paper discusses the role of n.m.r. in probing spatial heterogeneity in polymers using two characteristic features of n.m.r.: the short-range nature of the dipole–dipole interaction and the transport of spin energy (spin diffusion) that may occur over many tens of nanometres. The contribution of cross-relaxation is also examined briefly. Several illustrative examples are discussed.