Characterization of surface-modified poly(ethylene terephthalate) fibres by inverse gas chromatography

The effect of surface cleanliness on the alkaline hydrolysis of poly(ethyle ne terephthalate) fibres was investigated using inverse gas chromatography (IGC) in conjunction with mass loss measurements and electron microscopy. T he sizing agent was removed from the fibre surface by two methods: soxhlet cleaning in acetone and washing in an aqueous solution of a non-ionic deter gent. Alkaline hydrolysis was carried out using two concentrations of aqueo us sodium hydroxide, 1% and 10% by mass. The measurement of the specific re tention volume of undecane and the heat of adsorption using IGC indicated t hat the acetone cleaned samples were essentially surface contaminant free, while partial contamination of the surface by the sizing agent remained in the detergent cleaned samples. The presence of sizing agent significantly a ltered the degree of hydrolysis and the surface topography. The increasing values of the heat of adsorption indicated that significant surface hydroly sis increased the surface crystallinity. (C) 2000 Society of Chemical Indus try.