STRUCTURE OF AMORPHOUS POLYETHYLENE FROM NMR LINE-SHAPE ANALYSIS AND MAR-NMR

Based on results of proton nuclear magnetic resonance measurements with magic angle rotation (MAR n.m.r.), the line of amorphous polyethylene in conventionally measured proton n.m.r. spectra is described as a convolution of a basic narrow line-shape function S(v) with an orientation-dependent dipolar broadening function G(v). With this approach it is possible to describle to describe the broadline n.m.r. spectrum of polyethylene as a superposition of the crystalline component and of a single amorphous phase. The fit of experimental and computed spectra, and the parameters obtained by this type of line-shape analysis are discussed for a series of polyethylene samples of different crystallinity. © 1979.