Hydrophobic recovery behavior of PMMA and PEA ionomers treated with PSII

Abstract

The surfaces of poly(methyl methacrylate) (PMMA)-based and poly(ethyl acrylate) (PEA)-based ionomers were treated either with plasma or with plasma source ion implantation (PSII), and their hydrophobic recovery behavior was studied by measuring water contact angles. It was found that the hydrophobic recovery of the plasmatreated and PSII-treated surfaces of PMMA ionomers was much slower than that of the acid-form copolymers. This was due to the presence of hydrophilic ionic groups on the ionomer surface. In addition, in the case of the PMMA ionomers, a slow hydrophobic recovery behavior for a long period of time was observed. In the case of the PEA ionomer, the water contact angle values were found to be larger than those for the PMMA ionomers. When the contact angle values of the PMMA and PEA ionomers were compared to those of polystyrene (PS) ionomers, it was found that the order of ionomers showing higher angle value at comparable aging time was as follows: PS ionomer > PEA ionomer > PMMA ionomer. This was due to the difference in polarity and matrix glass transition temperature of the ionomers. (C) 2003 Wiley Periodicals, Inc.