MICROWAVE PLASMA REACTIONS OF SOLID MONOMERS WITH SILICONE ELASTOMER SURFACES - A SPECTROSCOPIC STUDY

A novel, microwave plasma method was developed and utilized to chemically bond solid monomers to the surface of cross-linked poly(dimethylsiloxane) (PDMS). By use of ATR FT-IR spectroscopy, it was found that maleic anhydride and acrylamide can be chemically bonded to the PDMS surface through the C=C bond opening. Such surface reactions are inhibited for succinic anhydride and propionamide which have the same respective structures but no C=C entities. The extent of surface reactions for maleic anhydride and acrylamide increases at higher microwave energy input and at lower initial gas pressures. The exposure to microwave radiation longer than 15 s, however, appears to be destructive to the surface. Utilizing microwave plasma treatments ranging from approximately 5 to 15 s, maleic anhydride and acrylamide can be chemically bound to the PDMS surface and the majority of anhydride and amide functionalities are maintained. Such functionalized PDMS surfaces can be further reacted by using base hydrolysis reactions.