Plasma polymerization of organosiloxanes

Plasma polymerization of disiloxanes containing various functional groups—hexamethyldisiloxane (HMDSO), tetramethyl‐1,3‐bis(chloromethyl)‐disiloxane (CMDSO), tetramethyl‐1,3‐bis(hydroxylbutyl)‐disiloxane (HBDSO), and tetramethyl‐1,3‐bis(amino propyl)‐disiloxane (APDSO)— was carried out using an inductively coupled electrodeless glow discharge. The monomer polymerization kinetics and the distribution of chemical species deposited showed that monomer reactivity varied among the different siloxanes. Monomers of APDSO and CMDSO possessed higher rates of polymerization. Polymer IR spectra and ESCA analyses indicated that the chemical structures of plasma‐polymerized products of HMDSO, HBDSO, and CMDSO resembled that of crosslinked polydimethylsiloxane. The polar hydroxyl and chlorine functionality in the HBDSO and CMDSO monomers was not present in the deposited films. In contrast, the polymerized product of APDSO retained amino functionality and also formed new Si–H bonds.