SURFACE FUNCTIONALIZATION OF POLYETHYLENE TEREPHTHALATE FILM AND MEMBRANES BY CONTROLLED WET CHEMISTRY .2. REACTIVITY ASSAYS OF HYDROXYL CHAIN-ENDS

Surface functionalization of polyethylene terephthalate film and track -etched microporous membranes was performed using organic synthesis at the solid-liquid interface. The hydroxyl chain ends, naturally occurr ing in the membranes or created by basic hydrolysis in the film, were activated by reaction with p-toluenesulfonyl chloride and then coupled to [4,5-H-3]lysine used as a model of water-soluble bioactive molecul es. The ratios of derivatization were determined by liquid scintillati on counting of the radioactivity associated with the samples. The hydr oxyl chain ends were further reacted with 4,4'-methylene di(phenyl iso cyanate); the resulting surfaces equipped with sensitive isocyanate sp acers were assayed as before using [4,5-H-3] lysine. The ranges of der ivatization were from 5 to 60 pmol of fixed amino acid per open surfac e unit (cm(2)). Some samples were also analyzed by X-ray photoelectron spectroscopy. (C) 1996 Academic Press, Inc.