X-ray photoelectron spectroscopy study of silane-treated newsprint-fibers

The nature of adhesion in multicomponent materials such as cellulosic fibers/thermoplastic composites is strongly dependent on the surface properties of the components. X-ray Photoelectron Spectroscopy (XPS) was used to characterize the surfaces of untreated and treated newsprint-fibers. Gamma-aminopropyltriethoxysilane and dichlorodiethylsilane were used for the surface modification of the fibers. The XPS analysis indicated that coupling between the silanes and the newsprint-fibers has occurred, and that silanols were adsorbed to the surface of newsprint-fibers by two different mechanisms: (1) an ether linkage between the silanols and the hydroxyl groups of the fibers and (2) a hydrogen bonding between the amine and the hydroxyl groups of the fibers. The formation of the hydrogen bonding was evidenced by the two observed amino states, i.e., a covalent non-protonated form and an ionic protonated form.