A broad-line n.m.r. investigation of methyl motion in poly(methylmethacrylate)

Broad line n.m.r. measurements have been carried out over a wide range of temperatures on poly(methylmethacrylate) (PMMA) and several selectively deuterated forms of this polymer. The line shapes and second moments for the different samples were examined in the light of theoretical calculations based on possible structural models. A spectrum subtraction procedure was particularly useful in confirming the conclusions drawn from consideration of second moment data. A consistent set of conclusions was obtained for the motion of the methyl groups.