Branching in Polyethylenes. Study by High Resolution Nuclear Magnetic Resonance

Abstract
The values of the CH3/CH2 ratios measured from accumulated NMR spectra of polyethylenes samples are in good agreement with those obtained from conventional IR techniques. Because NMR does not require calibration, systematic errors could be less important. Owing to the estimated values of the CH/CH3 ratios, tetrasubstituted carbon atoms are present in all the high-pressure polyethylene specimens.