| Abstract: | The surface treatment of a glass fiber using mercapto-functional silane coupling agent having a di- or trialkoxy group has been studied. The surface of silane-treated fiber is observed by scanning electron microscopy. The treated layer looks hard like glass for the trialkoxy silane-treated, whereas it looks soft for the dialkoxy silane-treated. Molecular mobility of the treated layer is analyzed by 1H pulse nuclear magnetic resonance spectroscopy. The amount of silane loading increases with increased silane concentration in the treatment solution. The relaxation time for the surface layer is longer for the dialkoxy structure than for the trialkoxy structure. The silane chain is flexible in the dialkoxy structure, but is rigid for the trialkoxy structure, independent of the loading amount of silane. The relaxation behavior for the mixture of the di- and trialkoxy structures is between those of the pure dialkoxy and trialkoxy structures and depends on the mixing ratio. The network density of silane chains on the glass fiber can be controlled by varying the mixing ratio of the di- and trialkoxy compounds. |
