FUMARIC-ACID AS AN ADHESION PROMOTER IN RAYON NYLON COMPOSITE FIBERS

Rayon/nylon skin/core composite fibers with enhanced adhesion were produced using a wire coating process. After spin finish removal by water washing, the nylon core fibers were pretreated with fumaric acid (FA) as an adhesion promoter and then coated with viscose rayon. Fourier transform infrared spectroscopy was used to identify the chemical bonds formed between FA and both rayon and nylon. The results indicate that carboxyl groups of FA reacted with amine end groups of nylon, forming amide bonds. Other carboxyl ends of FA reacted with hydroxyl groups of rayon, forming ester bonds. Due to the formation of these bonds, the interfacial adhesion in the composite fibers significantly improved under specific sets of application conditions.