PYROLYSIS GC/MS STUDIES ON PLASMA-POLYMERIZED PYRROLE

Pyrolysis gas chromatography/mass spectrometry and infrared spectrometry have been carried out for plasma-polymerized pyrrole (PPPy). The major thermal decomposition products have been identified as nitriles with less than four carbons and alkyl pyrroles. Evolution of only monosubstituted alkyl pyrroles, such as 2-methylpyrrole and 2-ethyl-pyrrole, suggests that PPPy consists of monosubstituted pyrrole rings. This is also supported by the result that the IR spectrum of PPPy differs from that of the electrochemically polymerized pyrrole, which consists of disubstituted pyrrole rings. Evolution of linear nitriles shows evidence that a PPPy molecule has the main chain containing nitrogen atoms. The mechanism of polymerization of pyrrole in the discharge is considered to be similar to that of aromatic hydrocarbons, which mechanism involves a process of production of acetylene.