Melt-State 13C MAS NMR Determination of Comonomer Type and Content in Ethylene/.alpha.-Olefin Copolymers

Melt-state 13 C NMR with magic angle spinning and dipolar decoupling is presented as an attractive method for the determination of comonomer type and content in polyolefins. The primary advantages of this approach are a decrease in analysis time and an ability to characterize samples not amenable to study by solution-state NMR. To illustrate this technique, five ethylene/α-olefins are characterized including a sample that had been rendered insoluble due to cross-linking and one that had been formulated into an inorganic matrix. In all cases, the melt-state approach yielded comonomer contents in good agreement with those obtained via solution-state NMR.