Characterization of plasma polymers from tetramethylsilane, octamethylcyclotetrasiloxane, and methyltrimethoxysilane

The products in inductively coupled plasma excited in organosilicic compounds were studied on chemical structures by spectroscopic methods. Plasma‐polymerized tetramethylsilane (PA) contains not only SiCH3 groups but also SiH groups on IR and 29Si‐NMR analyses. 13C‐NMR spectrum of PA reveals that the crosslinked structure of PA is mainly constructed of Ch2 and CH groups. Plasma‐polymerized octamethyleyclotetrasiloxane (PD4) is composed of SiCH3 and SiO groups. 13C‐ and 29Si‐NMR spectra of PD4 point out the highly preservation of the structural units similar to the monomer. These data of PD4 suggest that PD4 is formed from the ring‐opening polymerization by cleavages of SiO bonds. 13C‐NMR spectrum of poly[methyltrimethoxysilane] (PT) indicates the existence of CH3O groups, meanwhile its 29Si‐NMR analysis concludes that PT is chiefly composed of the structural units similar to the monomer. The surface analyses by XPS of PA, PD4 and PT suggest that these organosilicic plasma polymers resemble their starting materials.