Quantitative measurement of the effect of OH radicals on the surface treatment of polypropylene

Abstract

AbstractOH and O radicals are considered to be the most important reactive species in polymer surface treatment using plasma. However, the treatment effect of OH and O radicals has not been measured quantitatively due to the difficulty in separating the effects of OH and O from those of many other reactive species produced in plasma. In this study, the effect of OH radicals on the surface treatment of polypropylene (PP) is quantitatively measured using specially designed equipment that was developed in our previous research. The equipment produces OH radicals using vacuum ultraviolet photolysis of water vapor and supplies them to the PP surface while limiting the supply of other reactive species. The water contact angle on the PP surface is decreased by 1° per OH supply of [OH]τ = 7.1 × 1012 s/cm3, where τ is the treatment time.