WIM/WISE NMR studies of chain dynamics in solid polymers and blends

Wideline separation (WISE) NMR with windowless isotropic mixing (WIM) is de veloped as a method to study the dynamics of polymers and blends. This expe riment is designed to measure the dynamics of polymers through the proton l ineshapes that are correlated with the carbon chemical shifts in two-dimens ional NMR experiments. If the atoms experience large amplitude fluctuations that are fast compared to the dipolar broadening, then the proton lines wi ll be narrowed relative to rigid solids. We have modified the WISE experime nt by replacing the cross polarization step with WIM to quench spin diffusi on during the cross polarization so that the proton linewidths can be direc tly related to the chain dynamics. Two-dimensional WIM/WISE has been used t o measure the main-chain and side-chain dynamics in poly(n-butyl methacryla te) and blends of polystyrene and poly(vinyl methyl ether). (C) 2000 Academ ic Press.