A nondestructive analysis of silane coupling agents on E-glass cloth by transmission FTIR spectroscopy.

Fourier transform infrared transmission spectroscopy without destructive sample preparation was applied as a convenient method for evaluating the silane coupling treatment on E-glass cloth that is usually employed to make laminate boards. The glass cloth treated with a silane coupling agent, γ-anilinopropyltrimethoxysilane, was subjected to the measurement in the intact state. To eliminate the absorption and the scattering by the glass cloth from the spectra measured with the treated glass cloth, the difference spectra were obtained with the original cloth as a reference. Those spectra gave the same absorption bands as those of the coupling agent alone above 1200cm-1 The siloxane band was affected by the erosion of glass surface with acetic acid which was employed in silane treatment. When the cloth treated with acetic acid solution free from agents was used as another reference, the difference spectra gave no peaks due to siloxane formed on glass surface. This disappearance means that the siloxane bonds are not detectable in this method. In addition, the absorption bands due to the coupling agent treated on the glass were little given below 1200cm-1 These results are attributed to the anomalous dispersion near the intensive absorption due to the glass.