Investigation of interfacial structure of coupling agent treated fillers by fourier transform infrared spectroscopy and Attenuated Total Reflection-FTIR spectroscopy

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.