Investigation of interfacial structure of couping agent treated fillers by fourier transform infrared spectroscopy and attenuated total reflection‐FTIR spectroscopy

Abstract The interfacial structures of fillers treated by coupling agents were studied with FTIR and a Attenuated Total Reflection (ATR)‐FTIR spectrometer. The interfacial interaction was investigated by FTIR, and the nature of interaction was proved to be a chemical bonding, which could not be destroyed by extraction. Using a variable angle ATR technique, the average interfacial layer thickness of filler treated with different amounts of coupling agent was determined. A calibration curve was obtained from these studies to determine the optimal amount of coupling agent for different fillers, which was in agreement with the results of mechanical tests. ATR‐FTIR technique is a convenient method to determine the proper amount of coupling agent in composites.