Analysis of Ethylene Polymers and Copolymers by High Resolution Nuclear Magnetic Resonance ROGER S. PORTER, STEPHEN W. NICKSIC, and JULIAN
F. JOHNSON
California Research Corporation, Richmond, Calif.
b A series of ethylene polymers and copolymers has been analyzed by high resolution nuclear magnetic resonance. Various ester-containing monomerse.g., ethyl acrylate and vinyl acetatecopolymerized with ethylene have been identified and determined. NMR analyses compare well with copolymer determinations by pyrolysis-gas chromatography and by neutron activation analyses for oxygen. For certain ethylene homopolymers, NMR can provide a measure of molecular weight and chain branching. All measurements were made on 10% polymer solutions in diphenyl ether. A conventional Varian A-60 spectrometer was used. No special accessories were required. Polymer solutions in NMR tubes were heated to near 240" C. The tubes were then plcced in the conventional spectrometer probe followed by rapid scanning.
