Quantitative Determination of Comonomer Content in Ethene--alkene Copolymers by Solid State

1 H-MAS NMR is shown to be a powerful and attractive technique for quantifying the comonomer content in ethene--alkene copolymers, as exemplified by a series of ethene--hexene copolymers. The main advantages of applying 1 H-MAS solid-state NMR are related to; a) the very short experimental sampling time, on the order of a few minutes b) the bypass of sample preparation, as compared to traditional highresolution liquid-state 13 C-NMR which necessitates a high temperature (130 0 C) preparation period of days, or even weeks, c) no thermal sample treatment and d) no need for calibration. In particular, it will be shown that the technique allows the comonomer content of cross-linked LDPE to be probed, which is generally difficult, or impossible, by solution-state NMR since these polymers are mostly non-soluble.