The effect of chloro‐functional molecules on the ammonia plasma treatment of silicone elastomers

Attenuated total reflectance (ATR) FTIR spectroscopy was utilized for surface studies of ammonia/plasma‐modified poly(dimethylsiloxane) (PDMS) elastomer networks containing residual chloro‐functional molecules. Ammonia/plasma modification of PDMS containing chloro‐functional molecules causes the formation of surface amide groups, but due to the parallel formation of surface ammonium chloride, amide groups are not chemically bonded to the PDMS surface. The two primary sources of chlorine‐containing species are residual traces of freon and cross‐linking initiators present in the network. In the absence of chloro‐functional molecules, ammonia/plasma surface modifications of PDMS leads to the formation of stable surface amide groups.