Analysis of plasma‐polymerized hydrocarbons by pyrolysis/gas chromatography

Plasma‐polymerized oils, films and powders obtained from ethylene, acetylene, butadiene, and benzene were characterized by flash pyrolysis and gas chromatography (P/GC). None of the pyrograms resembled those of commercial polyethylene, polybutadiene, or polystyrene. Each of the plasma‐polymer pyrograms did exhibit essentially the same fragments up to C8, albeit in a different distribution, indicating that all samples are structurally similar. Analysis of the P/GC data shows these materials to contain a random arrangement of side chains, crosslinks, double bonds, and aromatic structures. Changes in the fragment distribution were obvious when the sample was a powder, solid film, or oily film produced from the same monomer. It was shown that powder products generally have a higher concentration of branches and/or crosslinks than the oil or film products. There are also differences in the pyrograms of products of the same form derived from dissimilar monomers. The results obtained from P/GC generally support those derived from infrared or NMR measurements performed earlier.